Table of Contents Subject Page IHKA Automatic Heating and Air Conditioning System Objectives of the M odule .2 Purpose of the System.3 System Overview .5 Air Conditioning System System Components.11 Principle of Operation.15 Workshop Hints.17 Heating System System Components.18 IHKA Heater and Air Conditioner Housing System Components.19 Control Panel/Control Module Detailed Controls.23 Temperature and Air Flow Control Principle of Operation.27 Air Distribution Principle of Operation.35 Stationary Functions Principle of Operation.45 Non-Air Conditioning Functions Rear Roller Blind Control.48 Coding Key Memory.50 Vehicle M emory.51 Workshop Hints.54 Review Questions 55 IHKA Automatic Heating and Air Conditioning System Model: E65 - 745i / E66 - 745Li Production Date: 11/2001 - E65, 01/2002 - E66 Objectives of The Module After Completing this module, you will be able to: List the gasses detected by the AUC-2 sensor. Explain how the refrigerant compressor output is varied. List the refrigerant compressor "Run In" procedure. Locate the blower motor and blower control module. Describe the control panel functions. Explain the "Y" factor. Explain how the temperature is increased during air conditioning operation List the functions that apply to heater operation when the coolant is cold. Demonstrate M anual Air Distribution individual adjustments. 2 E65 IHKA IHKA Automatic Heating and Air Conditioning System Purpose of The System The E65 IHKA automatic heating and air conditioning system is designed with technologi¬ cal improvements and new or modified functions. The design objectives for the E65 IH KA system meets the requirements of customers worldwide for heating and cooling capability. The control display provides indication and operation. Important primary functions are controlled by basic knobs and pushbuttons on the control panel which includes: Temperature control Blower speed Recirculating air Defrost Maximum Air Conditioning Rear window defogger Automatic functions I > • 42-14-01 1. IHKA Control Panel/Module 4. Face Vent Outlets 3. Upper Air Flow Outlets (defrost) 5. Front Footwell Outlets Customer Benefits: Straightforward understandable operation. Individual adjustment is possible using the virtual controls in the control display. Individual settings are stored in memory. The rear seating area has air inlet grilles in the center console and in the B pillars. The design allows direct and indirect air flow to all occupants. Individually adjustable temperature stratification (warm/cold). Consideration for warm and cold air distribution (head, chest and leg regions). The system prevents drafts. Primary function controls are grouped in a single unit that is readily visible and accessi¬ ble to the driver and front seat passenger. The temperable ventilation (air stratification) is controlled by adjusting elements in the air inlet grilles and the control display. 1 — iOv t 3 E65 IHKA IHKA automatic heating and air conditioning system features: Activated charcoal inlet air micro-filter Recirculation air filter Residual heat Independent ventilation AUC-2 sensor (gas sensor for automatic recirculation air control) 2 separate drives for outside air/recirculated air Air outlets in the B-pillars for rear passengers Solar sensor Vehicle and Key M emory for blower and temperature Dual temperature control (left/right) Automatic air distribution Airflow control Ventilation temperature stratification using the Controller in the Control Display menu Rear seat ventilation temperature control by the knurled knobs E65 innovations: Refrigerant Circuit Clutch-less refrigerant compressor is regulated externally by a pulse width modulation (PWM signal). Dryer integrated into condenser. Heater Circuit Auxiliary water pump is separate from dual water valve and installed in a remote position (easier to fill and bleed). Heater supply is from upper radiator hose for better accessibility and pressure limitation. IHKA Air Conditioner Layout with offset positioned blower unit. M odified functionality of the flap system for air flow control and stratification. Blower with single fan impeller. Blower control module (clock regulator with K-Bus and diagnosis capabilities). Flap drives (stepper motors) with blockage recognition. 4 E65 IHKA System Overview The heating and air conditioning system spans the entire vehicle. The major component locations including the optional rear air conditioner (E66) with cooler box is shown below. KT-7780 1. Heater and Air Conditioner housing assembly 2. Rear air conditioner with cooler box (E66 only) 3. Condenser (Not shown: refrigerant compressor and auxiliary fan) Overview of System Components Refrigerant System: The refrigerant system components include the following 1. Auxiliary fan with shroud 2. Condenser (2a) with integrated dryer (2b) 3. Refrigerant compressor 4. Pressure sensor (in the line) 5. Fill adapter pipe 6. Interface connection at bulkhead 7. Evaporator (inside the housing) 8. Shutoff valve (rear AC - E66) 9. Expansion valve 10. Pressure and suction lines for IHKA The layout includes two shutoff valves (one at the front for IH KA and one at the rear for E66 IHKA) and an additional evaporator with expansion valve. R134a refrigerant is used in the E65. The system capacity is 1.78 +/- .02 lbs (810 +/-10 grams). 5 E65 IHKA Heating System: Components of the heating circuit (coolant) with the N62 engine include 1. Return hose 2. Heat exchanger 3. Supply hose 4. Supply hose 5. Dual water valves 6. Electric auxiliary water pump 7. Supply hose 8. Hot coolant supply hose 9. Radiator 8214 Air Ducts: Air ducts refers to all components that distribute the air supplied by the fan to the outlets. The ends of the air ducts are fitted with directional grilles. 1. Air intake/filter housing 2. Defroster ducts 3. Ventilation ducts 4. B-pillar ventilation 5. Front footwell ducts 6. Outlet ducts in the instrument panel 7. Ventilation for rear seating area 8. Heating ducts for rear seating area 9. Side window air ducts 10. Heater/Air Conditioner housing Heater and Air Conditioner Housing: The IH KA housing is secured to the middle of the engine compartment bulkhead, underneath the instrument panel. The blower is mounted inside the passenger compartment offset to the passenger's side (in front of the glovebox). 6 E65 IH KA The IHKA housing is the central unit in the heating and air conditioning system, it performs the following functions: Create and control airflow Distribute the air M ix the air (air stratification) Dehumidify the air Convert the energy supplied by the cooling system Transfer the refrigeration power of the refrigerant system 8011 Layout of the IH KA major components (as viewed from the back) 1 . Defroster duct 11. Blower motor 2. Drive, warm air left 12. Blower control module 3. Ventilation, left 13. Evaporator 4. Heating exchanger 14. Condensation drain 5. Drive, defroster 15. Drive, footwell 6. Drive, cold air right 16. Drive, rear compartment ventilation 7. Drive, warm air right 17. Rear seat area duct, left, ventilation 8. Drive, recirculated air 18. Footwell/rear seat area outlet, left 9. Drive, fresh air 19. Footwell outlet, front left 10. Recirculated air flap 20. Drive, cold air left 7 E65 IHKA Control Panel/Control Module: The control panel is a dashboard insert with integrated electronic controls. The electronic circuits monitor and control the entire IH KA system. The control panel provides the essential basic controls. Precision adjustments are made using the Controller and the Control Display menu settings. IHKA control panel front view There are also controls for the hazard warning lights and central locking (Centerlock) func¬ tions (not part of IH KA system, only for location convenience). Functional Overview: DME (ECM)- Digital motor electronics PT-CAN - Bus cable K-CAN - Bus cable ZGM - Central gateway module MMI - control display TM - Door module SH ZH - auxiliary heating IHKA - E66 rear air conditioner PM - power module CAS - car access system ECU - IHKA control module LSZ - light switch center M PWR - stepper motors HR - rear window roller blind I/Os - inputs/outputs S-Sen - solar sensor AUCI/ll-Sen - AUC I and AUC II sensors B-Sen - fogging sensors (future) SI - limit position switch Poti - adjusting potentiometer 8 KT-8202 E65 IHKA Additional Sensors and Actuating Components: The system includes other compo nents in addition to those previously listed. AUC-2 sensor for automatic recirculated air control One solar sensor for each side One temperature sensor on each side in the center vent outlets One potentiometer on each side in the rear center outlets (for adjusting air stratification) One limit position switch on each side in the rear compartment center outlets AUC-2 Sensor: The AUC-2 sensor provides an input to the IHKA module that will auto¬ matically activate recirculation mode when excessive ambient pollution is detected. This sensor detects pollutant gases emitted by gasoline and diesel engines that include the fol¬ lowing: Hydrocarbons Carbon monoxide N itrogen oxides The heating and electronic analyzer (and software) are integrated into the sensor (located on the fan shroud). The sensor signal is pulse width modulated (PWM) to the IHKA control module. The sensoris self diagnosable. Within the first minute of operation it determines if there is a fault in the sensor electronics. A fault will be set in the IH KA control mod¬ ule when a fault is detected. Solar Sensor: The solar sensor is mounted on the dashboard top center grille. The black cap is visible which masks the diffuser and two (left and right) photo resistors. The cap only allows infrared light to pass through. The solar sensor supplies the control module with a separate signal for left and right. These signal levels depend on the intensity of the sunlight striking the sensor. The solar sensor influences: Blower output Opening angle of the ventilation flaps Air stratification temperature KT-8037 9 E65 IHKA Temperature Sensors: The various temperature readings used by the IHKA control mod¬ ule are supplied from the following sensors: In the Heater and Air Conditioner Housing Evaporator temperature sensor Two heat exchanger temperature sensors In the Control Panel Interior temperature sensor with blower On the Vehicle Exterior temperature sensor (signal provided overthe K-CAN bus) Center air outlet grill of the dashboard (one temperature sensor for each side, 1 right) Each temperature sensor consists of a Negative Temperature Coefficient (NTC) unit in a plastic housing with injection molded connectors. The IHKA control module interprets the varying analog voltage signals as changing temperature. The NTC units used for evapora¬ tor and heat exchanger have different resistances, so the holders are mechanically coded to ensure that the sensors cannot be installed in the wrong location. Microfilter System (Air Intake): There is a microfilter in each of the two air intake filter housings. The microfilters are a combination of particle filter and activated charcoal filter. The activated charcoal filters out unhealthy and noxious gases from the intake air before it enters the heater and air conditioner housing. The service life of the filter depends on the degree of air pollution in the operating environ¬ ment. The automatic recirculated air control function (AUC) with the filtration system pro¬ vides optimum protection forthe occupants of the car. The AUC function also prolongs the service life of the filter. 1. Inducted particles and gases 2. Particle filter (prefilter) 3. M icro-fiber matting 4. Carrier material 5. Activated charcoal filter 6. Covering layers, activated charcoal 10 E65 IHKA KT-8201 I Air Conditioning System System Components Refrigerant Compressor (KMV): The refrigerant compressor compresses the refrigerant gas inducted from the evaporator and forces it to the condenser. The compressor does not have a clutch and it always operates when the engine is running. The compressor output is variable and is controlled internally by signals from the IHKA control module. Delivery rate and pressure is produced by seven pistons. The piston stroke is influenced by a swash plate. 1. Solenoid valve 2. Hollow piston (Teflon coated) 3. Swash plate (M 0 S 2 coated) 4. Belt pulley 5. Rubber elements KT-8339 Clutchless Drive Advantages Application and Function Compact Saves Weight No electric power consumption The illustration (right) shows the design of the refrigerant compressor drive with rubber ele¬ ments. 1. Splines in the drive hub 2. Drive hub contour 3. Splined shaft 4. Rubber elements 5. Belt pulley The rubber elements mesh with drive hub con¬ tour and will deform to give way (slip) if the compressor seizes. Vibration damping function Torgue transmission Protective function in the event of a blockage KT-8338 11 E65 IHKA The position of the swash plate is varied by the internal pressure which is controlled by the electric control valve integrated into the compressor. The control valve influences the force at the swash plate by changing the crankcase chamber pressure (Pc). When de-energized (control valve open), the swash plate is almost vertical and not deflected. The compressor output is approximately 0 - 2% which is required to maintain internal lubrication. The IH KA control module sends a pulse width modulated signal (12V, 0.85A at 400 Hz) to close the control valve. This causes the pressure in the crankcase chamberto diminish. The swash plate is deflected (angled) and the compressor output increases (variable between 2 - 100 %). KT-8279 1. Orifice between crank case chamber pressure Pc and intake pressure Ps 2. Crankcase chamber pressure Pc 3. Gas flow 4. Spring 2 5. Coil 6. Valve tappet 7. High pressure Pd 8. Bellows with spring 1 9. Intake pressure Ps Condenser with Dryer: Compressing the refrigerant gas in the compressor causes the temperature to rise. This heat energy is dissipated to the environment by air cooling the sur¬ face of the condenser, which causes the refrigerant to condenses and become liquid. 12 E65 IH KA Any moisture that might be present in the sys¬ tem is trapped in the integral dryer to avoid cor¬ rosion damage in the refrigerant system. The dryer insert (1) is replaceable. The granulat¬ ed desiccant can absorb up to a maximum of 8 grams of water. It is important to keep the refrigerant system sealed for as long as possible when performing repairs. Auxiliary Fan (ZL): The auxiliary fan (approx. 420 mm diameter) has 5 asymmetrically rear¬ ward curved blades. The motor is the brushless type with electronic commutation (no brushes to wear). The fan speed is variable from 30 to 100%. The required fan speed is requested by the IH KA to the EC M over the CAN bus. The ECM sends a PWM control signal to the fan motor final stage (integrated into the fan housing). At lower speeds and standstill (engine idling) cooling is assisted and maintained by the auxiliary fan. The auxiliary fan is deactivated at vehicle speeds > 80 km/h (fan stage 0 is output). At high¬ er vehicle speeds, ram air is sufficient to cool the condenser. The auxiliary fan is activated when the vehicle speed drops below 70 km/h. The operating stage depends on the refrig¬ erant pressure. There are 15 possible speeds depending on refrigerant system pressures. KT-8204 Pressure Sensor: The pressure sensor is in the pressure line between condenser and the evaporator. The sensor sends the IHKA control module an analog signal between 0.4V and 4.6V as a rep¬ resentation of system pressure. The 5V supply is provided by the IHKA control module and the sensor current consumption is < 20 mA. KT-8205 13 E65 IHKA Expansion Valve: The block type expansion valve in the E65 functions the same els currently in use. The expansion valve is mounted directly on the evaporator conditioner housing (accessable from the driver's side) and controls the inlet rate fied refrigerant into the evaporator. This ensures that the evaporator receives only as much liquefied refrigerant as it can evaporate (supply side = liquid/blue, outlet side = gas/red). 1. From evaporator 2. To evaporator 3. From condenser 4. To refrigerant compressor as mod- in the air of lique- 1 KT-8207 Evaporator: The evaporator is an aluminum plate type surface that consists of 27 plates with a total surface area of approximately 5 square meters. To avoid corrosion, the evapo¬ rator has a very thin coating to speed conden¬ sation drain off. Cooling the air causes some of the contained moisture (humidity) to condense, so the evapo¬ rator control is set not to drop below approxi¬ mately 2 2 C in orderto prevent ice from forming. The temperature is monitored by the evaporator temperature sensor. KT-8212 Notes: 14 E65 IHKA Principle of Operation Evaporator Temperature Control and Refrigerant Circuit Monitoring The evaporator temperature control keeps the evaporator temperature at a constant 2 2 C and operates independently of the other control circuits. The variable output to the refrig¬ erant compressor is derived from or limited by the following criteria: Difference between requested setting and actual value of the evaporator temperature Compressor speed Coolant temperature Compressor load torque Torque limitation Refrigerant pressure limitation Kick down (vehicle acceleration) Battery voltage Requested Setting and Actual Evaporator Temperature Difference The cold air exiting from the evaporator is reheated to the desired temperature by the heat exchanger. To control ventilation, the measured evaporator temperature is used as an influ¬ encing variable to compute the angle of the cold air flap. Refrigerant Compressor The compressor is activated on demand when all switch on criteria is met. It is an internal¬ ly regulated and externally controlled compressor. The control valve is the manipulated by a variable PW M (400 Hz) signal to ensure that only the refrigeration required at a given time is generated by the compressor. This reduces the load when full cooling power is not need¬ ed. Compressor Speed K-CAN messages provide the IH KA with engine speed information (from the ECM) which represents compressor speed. 15 E65 IH KA Compressor Load Torque The variable load torque is derived from the evaporator temperatures (requested setting and actual) by the IH KA to generate the PW M signal for the solenoid valve to deflect the swash plate. The physical compressor load torque requirement is calculated by the IHKA control module and sent to the ECM overthe K-CAN Bus. Torque Limitation The IHKA receives a K-CAN message from the ECM containing a maximum specified torque. Under full throttle/kick down and at high coolant temperatures, the EC M uses this signal to restrict the maximum possible compressor load torque. Refrigerant Pressure Limitation The refrigerant pressure is monitored through the pressure sensor to avoid excessive sys¬ tem high side pressures. The IHKA limits refrigerating power linearly from 100% to 0% (shutdown) between 22 to 28 bar of pressure. The compressor is deactivated when the pressure is < 1.8 bar. The compressor is reacti¬ vated when the pressure is > 2 bar, provided that all the other switch on criteria is met. Compressor - Running In When the compressor is operated forthe first time it must be run in to ensure proper lubri¬ cation (oil distribution). During the Running In procedure the compressor must be operat¬ ed at speeds between 300 to 1200 rpm. If the speed drops below 300 rpm or rises above 1200 rpm during the Running In phase, it is interrupted and automatically resumed after a delay of 5 seconds (refer to Service Functions). Communication between IHKA and the ECM The IHKA notifies the ECM of the request for compressor activation in a K-CAN message (Control A/C ready). 16 E65 IHKA In anticipation of the compressor load and based on the outside temperature, this is accomplished by increasing engine idle speed from 550 to 750 rpm. There are three different switching criteria: 0 = No air conditioning required, system ON 1 = Air conditioning required, system ON without speed increase 2 = Air conditioning required, system ON with speed increase The ECM provides the IHKA with a torque of 30 Nm, provided that deactivation criteria does not apply (high coolant temperature, kick-down, etc.). The IHKA will activate the refrigerant compressor in the permitted torque range and reports the actual torque applied back to the ECM . Limitation of Compressor activation by the ECM The ECM sends a K-CAN message notifying the IHKA of the maximum available torque. If this maximum available torque is less than the current compressor load torque, the valve signal is reduced until the load of the compressor drops to or below this value. If this can not be accomplished by the minimum valve signal, the compressor is shut down. Workshop Hints Initial Operation after Replacing the Refrigerant Compressor When the compressor is operated for the first time (after replacement) it must be run in to ensure proper lubrication (oil distribution)! Procedure: 1. Set all air vents in the instrument panel to "OPEN". 2. Start the engine and wait until it stabilizes at a constant idle speed. 3. Set the speed blower to at least 75% of the maximum output. 4. Switch on the A/C system and allow it to operate for at least 2 minutes at idle speed (risk of damage at higher speed). Note: The engine speed must not exceed 1200 rpm. If it does, the procedure will auto¬ matically abort and must be repeated. Consult the Repair Information (in TIS) for the correct compressor oil filling procedure and the Running In phase that allows thorough and uniform mixing with the refrigerant. 17 E65 IHKA Heating System System Components Auxiliary Water Pump (ZWP): The ZWP is a rotary pump with an electronically commut¬ ed direct current motor. The pump housing is sealed from the motor. Drive from the motor is transmitted to the impeller through the sealing partition. The ZWP is protected against blockage and reverse polarity. In the event of a thermal overload, power is reduced down to intermittent operation. The ZWP enhances hot water flow (1 - outlet, 2 - inlet) and ensures the minimum flow rate, particularly when the engine is idling or off (residual heat function). Dual Water Valve (WV): The dual water valve operates electro mag netically to meter the volume of coolant flow to the left and right heat exchangers. This function is performed by an open/close ratio that the IHKA control module varies according to the demand. The valves are sprung open when de-energized. 1. Left heat exchanger circuit 2. Hot coolant inlet 3. Right heat exchanger circuit Heat Exchanger (WT):The aluminum heat exchanger is the flat tube type consisting of two halves (left and right) with one inlet for each and a common outlet. It transfers the ther¬ mal energy supplied by the flow of heated coolant to the air flowing through. Under ideal conditions as much as 10 kW of heating power can be produced. There are two heat-exchanger temperature sensors located in the air stream (left/right) that measure the exiting air tempera¬ ture. 18 E65 IHKA KT-8210 2 KT-8206 IHKA Heater and Air Conditioner Housing System Components The Heater and Air Conditioner Housing consists of the following components/functional units: Evaporator/evaporator sensor Heat exchanger/sensor Blower Blower speed control module Flaps/flap actuating mechanism Flap drives/stepper motors Flap Drives: 1. Warm air left 2. Defrost 3. Fresh air 4. Recirculated air 5. Warm air right 6. Cold air right 7. Footwell right 8. Rear seating area right 9. Rear seating area left 10. Footwell left 11. Cold air left 9S7 KT-8376 Blower: The blower assembly is a radial flow blower with a fan impeller on one side. It is mounted with the blower motor in a sound proofed housing (1), offset to the passenger's side. The blower control module can be sepa¬ rated from the motor. The blower produces the required air mass flow and under ideal conditions can achieve a maximum flow rate of approximately 9 kg/min. KT-8346 19 E65 IHKA Depending on the positions ofthe airflow control flaps, the required quantity of airis induct¬ ed either through the fresh air filters or through the recirculated air flap depending on the operating status. Technical data of the blower motor: Type Permanent Direct current motor Voltage 12 V Rated speed 3350 rpm Rated current consumption 27 A Blower Control Module: The blower control module is mounted directly on the blower motor housing. It has self diagnosis capabilities and is addressed by the IHKA control module over the K-bus (view from below inside open IHKA housing). 1. Blower control module 2. Blower KT-8208 The blower control module uses a "clocked" regulator which reduces control power losses. This significantly saves energy and requires a smaller heat sink. The diagnostic information is transmitted to the IHKA control module for processing. If a fault is detected in the regulator or blower that would cause an overload (overheat), current is reduced or the blower is temporarily shut down. Flaps/Flap Actuating Mechanism: The flaps distribute the air and mix cold air with warm air. The flap actuating mechanism includes the flaps, corresponding shafts with lever assemblies and the drive motors. The flaps in the IHKA are as follows: Fresh Air Flap: This flap regulates the quantity of fresh air inducted by the blower. It is actu¬ ated by a rapid action drive to close quickly when the system is operating in automatic recirculation air mode (AUC mode). This flap also acts as a dynamic pressure compen¬ sator. 20 E65 IHKA Recirculation Air Flap: This flap is a three vane louver (1). The recirculation air flap regulates the volume of recirculated air inducted into the system. The recirculating air filter is located directly above it. FootweliFlap: These flaps (separate for left and right) control the flow of air to the front and rear footw ells. Rear Seating Area Ventilation Flap: These flaps regulate the volume of airflow and the temperature (air stratification) from the rear ventilation outlets (separate flaps for left and right). Defrosting Flaps: These two flaps are coupled together to regulate the air flow against the windshield. In all adjustment and control functions, these two flaps are controlled from the driver's side only. Warm Air/Cold Air Flap: These flaps control the airflow/temperature stratification to the outlets in the dashboard and B pillars (separate flaps for left and right). Each pair of flaps (warm air/cold air) regulate the airflow and the temperature at the same time. KT-8347 Flap Drives/Stepper Motors: All flap drives are designed basically the same, including the following components: Stepper motor Plug housing Reduction gearing The external distinguishing features are the dif¬ ferent types of levers and rods and the physical configuration (alignment) of the connectors. The drives are decured by clips. IH KA has a total of 11 stepper motors: 10 Stepper motors for all other flaps 21 E65 H KA 1 Rapid action motor for the fresh air flap Rapid Action Motor (Fresh Air Flap): The windings of this drive are actuated directly by the IH KA control module at a stepping freguency up to 500 Hz. The rapid action motortorgue depends on the stepping freguency, not on the supply voltage. Stepper Motors (All Other Flaps): Each of these motors contain an integrated circuit (M UX- 4 chip) in the plug connection housing. This 1C controls the windings of the motor and is linked by a motor bus with diagnosis capabilities. All stepper motor drives are controlled by the IH KA control module over the motor bus. Each drive has a permanent address (stored on the chip) which is a unigue identifier for the individual motor (for bus communication). The stepper motors are all different and are not interchangeable. Faults (blockages) reported by the drives are stored in the IH KA control module, which responds by discontinuing control signals to the motor in guestion. Notes: 22 E65 IH KA Control Panel/Control Module i KT-8297 The IHKA detailed controls are: 1. AUTO left button (LED: green) 2. Recirculated air/AUC button (LED: both green) 3. DEFROST button (LED: orange) 4. TEMPERATURE left knob 5. MAX AC button (LED: green) 6. AIR VOLUME left knob 7. System OFF button (LED: orange when system is switched off) 8. AIR VOLUME right knob 9. TEMPERATURE right knob 10. REST button - residual heat mode (LED: green) 11. Rear window defroster button (LED: orange) 12. Air Conditioner button (LED: green) 13. AUTO right button (LED: green) 14. Air grill for interior temperature sensor 15. Parked-car ventilation system indicator (flashing when activated) 23 E65 IHKA Function Operations Based on Ignition Switch Positions Terminal 30 (Ignition OFF) Terminal 15 Terminal R (Accessory Position) Residual heat (Rest function) Parked-car ventilation AUTO (residual heat/parked-car ventilation) OFF (residual heat/parked-car ventilation are deactivated when "OFF" is selected) Residual heat (Rest function) Parked-car ventilation Parked-car ventilation AUTO Driver AUTO Front passenger AC DEFROST MAX AC Recirculating air AUC HHS (rear window defroster) OFF Communication Between IHKA and Control Display The following messages are interchanged between the IH KA and the Control Display over the K-CAN bus: From Control Display to IH KA: Operation of air conditioner, front Operation of air distribution, driver's side Operation of air distribution, passenger's side From IHKA to Control Display: Status of air conditioner, front Status of air distribution, driver's side Status of air distribution, passenger's side Functions of Other Buttons on the Control Panel CENTERLOCK: The status of the CENTERLOCK button is looped through the IHKA to the appropriate control module. HAZARD WARNING LIGHTS: The status of the HAZARD WARNING LIGHTS button is looped through the IH KA to the appropriate control module. The hazard warning lights indi¬ cator LED is activated by the lights switching center. Connected Loads The power requirement of the control module is 16 Amp (max.). 24 E65 IHKA Connections at the Back of the Control Panel/Control Module The rear of the control panel accommodates All plug in connections to the vehicle electrical supply and to the heater/air conditioner components Connection to the K-CAN bus Replaceable sensor blower (directs air onto the integrated interior temperature sensor) Rear View of the Control Panel: 1. Replaceable sensor blower 2. Pin receptacle 04, 3-pin, black 3. Pin receptacle 03, 12-pin, blue 4. Pin receptacle 01, 12-pin, black 5. Pin receptacle 05, 5-pin, black 6. Pin receptacle 02, 26-pin, blue Notes: 25 E65 IHKA M1 to M10 - Flap drives (stepper motors) BEL AB - Ventilation for storage box (future) WHZG - Wiper parked zone heating Mil - Fresh air flap PM - Power module WTFL - Pleat exchanger temperature sensor, left KMV - Refrigerant compressor WTFR - Pleat exchanger temperature sensor, right HSR - Rear window roller blind VDF - Evaporator temperature sensor KL30 - Terminal 30 F2 - Fresh air grill, front GEB - Blower DSEN - Refrigerant pressure sensor CON - Controller AUC - Automatic recirculated air control BZM - Center armrest control console WV - Water valve CD - Control Display ZWP - Auxiliary water pump DME - (ECM) Digital engine electronics LM - Light module ZGM - Central gateway module WB - Plazard warning lights system SP - Blocking circuit CTL - Centerlock HHS - Rear window defroster CAS - Car Access System AT - Antenna tuner SSEN - Solar sensor PT-CAN - Powertrain bus FI - Fresh air grill, rear seating K-CAN S - Body controller area network system BSEN - Fogging sensor (future) Functional Circuit Diagram 26 E65 IHKA Temperature and Air Flow Control Principle of Operation Temperature Control The basis of the temperature control system consists of the left and right master controllers (Y Factor). These controllers compare the interior temperature actual value with the occu¬ pant's requested temperature settings for left and right. The control obtains a differential signal, which it uses to generate the variable Y (factor). The operating range of the master control is from - 200% to + 311.5% Y. A wide variety of functions in the IHKA are influenced by this, for example: the flap and automatic blower control. The subordinate systems include two auxiliary regulating circuits for the left and right heat exchangers to suppress the temperature fluctuations in air throughput or water flow. Two other independent loops control the ventilation temperature for left and right, thus allowing stratification of the air temperature between the footwell outlets and the ventilation outlets. Passenger Compartment Control (Master Controller) The passenger compartment controller is proportional (linear). The temperature range that the vehicle's occupants can select is from approx. 61 s F to 90 s F (16 s C to 32 s C). The step interval is: Temperature 2 F in increments of 1.0 2 F Temperature 2 C in increments of 0.5 2 C 42 - 14-11 MAX Heating Function When the setpoint is 32 2 C, MAX heating is activated for left and/or right individually. The interior temperature controller is overridden. The temperature of the heat exchanger is brought up to the maximum of 90 2 C. The variable Y is set to maximum heating (true 311.5%). Exception: The water valves will remain closed in the parked-car ventilation mode, so the MAX heating function is cancelled. 27 E65 IHKA MAX Cooling Function When the setpoint is 61 s F, MAX cooling is activated for left and/or right indi¬ vidually. The interior temperature controller is overridden. The heat exchang¬ er temperature is reduced to the minimum of 5 2 C and the water valve(s) is closed. The variable Y is set to -200% (maximum cooling) and the recircu¬ lation mode automatically takes place. 42 - 14-11 Correction for Setpoints Outside Temperature Influence: The outside temperature is registered by a sensor at the bumper and is sent to the IH KA over the K-CAN bus. The setpoint is corrected to com¬ pensate for the effects on the vehicle's occupants from radiant heat. The outside temper¬ ature influence and the associated setpoint increase can be between +12 to -2 2 C. Interior Temperature Sensor: The temperature sensor measures the temperature inside the passenger compartment. This temperature sensorfurnishes the most important, the sen¬ sor value is monitored and processed at a very high resolution (0.1667 2 C). Heat Exchanger Control The temperature of the heat exchangers is monitored by temperature sensors situated directly in the discharge air flow (left and right). The heat exchanger setpoint is calculated on the basis of the master controller's variable Y to correct fluctuations in heat exchanger temperature. Exception: If the variable Y factor is < 0%, the water valve of the heat exchanger(s) is closed. Heat Exchanger Characteristic Map The duration of water valve(s) opening compensates temperature control based on a speed dependent heat exchanger characteristic map for various engine speeds. Pulse width modulation from the IH KA controls the water valves to open longer for lower engine rpm and open shorter for higher rpm. 28 E65 IH KA Filling Station Effect The filling station effect occurs when the valves are de-energized (sprung open), allowing the heat exchanger to filll with hot coolant. This is avoided by maintaining the power sup¬ ply to the water valves for 3 minutes after KL15 is switched "OFF". Engine Characteristic-Map Cooling To avoid damage to the heater and air conditioner, the heat exchanger temperature is lim¬ ited to a maximum of 90 2 C. If a defective water valve causes the temperature in the heat exchanger to rise too high (> 98 2 C), a K-CAN message is sent to activate the Characteristic-Map cooling in the ECM . Auxiliary Water Pump The electric auxiliary water pump ensures that the requested water flow rate is maintained even at low engine speeds. ON: Residual Heat Function or KLI5 ON and Engine temperature > 0 2 C and Blower not on zero setting and Variable Y (driver or passenger) > 5% or DEFROST or MAX heating OFF: Residual heat function not active and KL15 OFF or Engine temperature < 0 2 C or Blower setting on zero or Variable Y (driver or passenger) < 0% and DEFROST not active and MAX heating not set 29 E65 IHKA Face Vent Outlet Stratification To achieve the air temperature and airflow rate, output is calculated taking the following variables into account: Temperature setting selected by the occupants (variable Y) Air stratification setting using the Controller in the Control Display settings menu Ventilation temperature (actual value) Solar sensor Outside temperature Flap characteristics for the footwell DEFROST ON/OFF Correction factors Temperatures of evaporator and heat exchanger Once the face vent outlet stratification is set, characteristics are applied to correct the posi¬ tions of the cold air and warm air flaps (air mix) to achieve the desired flow rate and tem¬ perature at the ventilation outlet. The proportions of the warm and cold air flow deter¬ mines the ventilation temperature. This affects the tem¬ perature and the airflow rate in the entire system each time the angle of a flaps is changed. 1. Face vent outlet duct 2. Airflow to ventilation (ventilation temperature) 3. Cold air flap position 4. Cold airflow (evaporatortemperature) 5. Warm airflow (heat exchanger temperature) 6. Warm air flap position KT-7792 Ventilation Control (Stratification) Front The inputs used to generate the setting for the face vent temperature are Temperature variable (Y) Stratification using the Controller in the Control Display settings menu Solar sensor value Outside temperature 30 E65 IH KA The setpoint calculation for the ventilation temperature is based on the heat exchangerand evaporator temperatures. The calculation provides the approximated flap angles to pro¬ duce the ventilation temperature. There are ventilation sensors (left and right) to monitor the ventilation temperature. These sensors allow the IHKA to monitor the true ventilation temperature which is compared to the requested ventilation temperature. The IHKA will "fine tune" the flaps to decrease the difference. The angle of the footwell flap is taken into account as a factor for the volume of air that is lost when the footwell flap is open. The variable (Y) function is added to force the warm air flap open in cooling mode (heat exchanger cold) to increase the air volume flow. 1. Evaporator 2. Heat exchanger 3. Warm air flap 4. Cold air flap 5. Flap for rear seating ventilation (warm air, cold air and shut off) KT-8345 Ventilation Control (stratification) Rear The air stratification flaps forthe rearof the passengercompartment (left/right are separate) discharge perform two functions: Shut off the flow of air to the vents (shut off flaps at the vents are closed manually) Control the discharge temperature by mixing warm air and cold air (flap 5 above) The limit position switches atthe shut off flaps ofthe center vent will signal a requestto the IH KA to closed or open the supply flap (flap 5 above). 31 E65 IHKA Air Flow Control Automatic Blower and Flap Control 42-14-06 When the "AUTO" button (left or right) is pressed ora request is made by using the Control Display, the automatic blower and flap control is activated (depends on variable Y) and the "AUTO" LED is illuminated. When the blowercontrol knob is turned, automatic blowercon- trol (forthat)side is deactivated. Automatic flap control remains active. Pressing the "AUTO" button again reactivates automatic blowercontrol. The current blower output is displayed on the Control Display in manual mode only. Dynamic Pressure Compensation As vehicle speed increases, the increase in "ram air" is controlled by Dynamic Pressure Compensation to maintain consistent airflow volume. The ram air is compensated by clos¬ ing down the fresh air flap to restrict the air intake duct in response to the road speed sig¬ nal (over K-CAN). To prevent the flap position from being changed continuously in response to minor changes in road speed (overcompensation), buffering is included in the calculation for the desired flap position. In the 80 to 180 km/h speed range, the fresh air flap angle is reduced from 100% to 30%. Manual Blower Adjustment 42-14-09 Turning the control knob(s) clockwise increases blower output and counter clockwise decrease output. The knobs do not have limit stops and detente in stages from 1 - 14 (power is increased ordecreased one level foreach click). Bloweroutput is visualized in the bar indicator in the Control Display. Once the maximum or minimum set¬ ting is reached, turning the poten¬ tiometer further in the same direction has no additional effect and output remains at the MAX or MIN setting. The new blower value is immediate¬ ly transmitted to the Control Display. A. Manual blower setting B. Bloweroutput C. Potentiometer detent position D. Blower stage A 32 E65 IH KA Automatic Blower Boost Automatic blower boost is avail¬ able when the flaps are adjusted manually or automatically. A. - Blower output Y. - FA variable, driver's side tw -i» m *» «c 1&9 IK ho an V- FA ——————— To expedite cooling or heating to counter extreme cabin temperatures, the normal range of adjustment (Y) is increased to - 200% ... 310%. Automatic blower control only responds to the driver's side value. Limitation in Cold and Warm Ranges When the variable (Y) > 10%, maximum bloweroutput is limited as a function of coolant tempera¬ ture. This avoids unwanted cold air drafts until warm air can be pro¬ duced. A. Limitation in cold/warm ranges B. Coolant temperature C. Maximum blower output A (V > 10 %| y: ‘ C {%) rci H p in M 40 3 rq KT-8738 Blower Control Function Based on Electricity Supply When the power module triggers a consumer shutdown over the K-CAN bus, the follow¬ ing applies: Blower Output Prioritv Level OFF 1 50% 4 100% >4 33 E65 IHKA Note: The reduction in bloweroutput orshutdown for priority level 1 or4 does not apply to the "DEFROST" function. Blower voltage is reduced in the same ratio as the vehicle voltage from 12.0 V downward Effect of Terminal 50 (Start Signal) During engine starting, the battery is not subjected to the extra load by the blower current consumption. As long as "KL50 logically on" remains (starter motor), the blower control voltage is held at OV (blower off). Fault Handling, Terminal 50: A communication defect affecting the "terminal 50 logically on" bus message will shut down the blower and the duration of the active state (KL50) is monitored. The "Terminal 50 Logically On" Status is overridden When: KL50 active for longer than 30 seconds Engine speed >500 rpm "Engine running" K-bus message is received The original KL50 status is considered invalid, and although no fault message is in memo¬ ry the function is "logically off". The blower circuit remains inactive until KL15 is switched "OFF". The blower circuit is reactivated by the next KL15 ignition "ON" status. Notes: 34 E65 IH KA Air Distribution Principle of Operation There are a number of ways to select the air distribution mode: Automatic program - selectable by the button on the control panel or the air condition¬ ing menu on the Control Display. Prioritized programs - selectable by the buttons on the control panel. Manual air distribution programs - selectable by the air conditioning menu on the Control Display. INDIVIDUAL settings (no program) - selectable by the DUAL function in the air condi¬ tioning menu on the Control Display (future). The air distribution status is always transmitted to the Control Display for the flap range from 0% (flap closed) to 100% (flap open). Flap Positions The flaps are positioned according to the driver's side control setting (including Y). The LHD/RHD ID is needed forthis purpose when coding. The flaps and positions that are acti¬ vated (together) for both sides of the heater and air conditioner unit are: fresh air, recircu¬ lating air and Defrost. Flap Position Priorities The initial position of each flap is defined in according to the following priorities Calibrating run (after connection of the battery) Parked-car ventilation OR utilization of residual heat (Rest feature) Position run (when KL15 is switched OFF) DEFROST program MAX-AC program OFF mode (blowerzero position) Cold starting interlock 35 E65 IHKA If one of these functions is active, the nominal positions of the motors are used. If none of these functions are active, the nominal position is recalculated for each flap, taking into account the button selected (flap program). Calibration Run The stepper motors do not have a "feedback" function to recognize the actual positions, they always move to a reference position. The reference position is the flap limit positions 0% or 100%. The flaps always move to a limit position for each "power-on reset" (reconnect battery). This allows the IHKA to start from the reference to properly position the flaps during normal operation. A calibrating run can also be initiated by the DISplus. Overflow When at the limit position (0% or 100%), the fresh air flap is subjected to an OVERRUN (precautionary measure). In OVERRUN, the stepper motor is sent "10 overrun steps" every 20 seconds. The fresh air motor is sent overrun steps in the CLOSED direction (so flap is sealed correctly) and in the OPEN direction (correction if the flap is frozen closed). Position Run When the ignition (KL15) is switched "OFF", the fresh air/recirculated air flap is moved to the "fresh air position". This ensures the supply of outside air to the passenger compart¬ ment in the event of an IH KA failure. Manual (Individual) Air Distribution Manual air distribution is controlled through the Control Display. The IHKA provides separate individual air distri¬ bution settings to increase /decrease airflow for the driver's and passenger's side. 36 E65 IHKA 42-14-17 Automatic Program Defrosting flaps To avoid post start fogging, the defroster flap remains closed for 12 seconds after the engine is started, before operations return to normal. When the DEFROST function is can¬ celled, the defroster flap is moved to the new flap position (after a slight delay). When the AUTO button on the driver's side is pressed, the defroster flaps are opened or closed according to program variable (Y). The AUTO button on the passen¬ ger's side does not effect the posi¬ tion of the defroster flaps. A. Variable Y B. Flap aperture Footwell Flaps When the AUTO button on the dri¬ ver's or passenger's side is pressed, the footwell flaps are opened or closed according the the variable (Y) program. A. Variable Y B. Flap angle KT-8743 Settings for the "INDIVIDUAL" Program The flaps that can be set individually by the Control Display are Drivers Side Passenger's Side 37 E65 IHKA Defroster flap Virtual flap Footwell flap Virtual flap Footwell flap When the positions of the flaps on the left side are changed, the program set for the right side is deleted. The individual settings allow the flaps on the left and right sides to be opened or closed sepa¬ rately in steps of 10%. The correct flap positions are held and can be called up with the INDIVIDUAL program. Special Case: When a special program is active (MAX-AC, DEFROST, etc.) the program selected beforehand is reselected initially if an individual air distribution setting is selected. Cold-Starting Interlock Cold-starting interlock avoids unwanted cold air drafts until warm air can be produced and is activated with the following conditions: ON: Variable (Y) DRIVER setting = 100% and AUTO program selected and Heat exchanger temp, driver's side < 30 2 C Cold-starting interlock is deactivated when any one of the three conditions is not met. The flap positions for cold-starting interlock depends on the outside temperature. If outside temperature is < 0 2 C, the defroster flap is OPEN and the footwell flaps CLOSED. The opposite applies for outside temperatures > 0 2 C. MAX-AC Function The MAX-AC function enables the user to select the maximum cooling powerby a single touch of a button on the control panel. The MAX-AC func¬ tion has the highest priority after the DEFROST function. All functions including DEFROST are deactivated when the MAX-AC button is pressed and the air conditioning function is switched on. The air conditioning function will remain active when the MAX-AC function is terminated. 42-14-11 38 E65 IH KA The MAX-AC function is terminated when any button on the control panel is pressed ora change made to the settings on the Control Display. The newly selected function becomes active and the settings selected before the MAX-AC function are reactivated (except DEFROST). Pressing the MAX-AC button while the MAX-AC function is active also termi¬ nates the MAX-AC function. Special functions in conjunction with the MAX-AC function M ulti-function steering wheel (MFL) actuation: When the MAX-AC function is active there is no reaction to the MFL controls. DEFROST Function The DEFROST function is a priority function in air distribution. DEFROST is activated by pressing the DEF button. The DEFROST function is the highest priority function after the OFF function. When the DEFROST function is acti¬ vated all the function LEDs go out, with the exception of the rear window heating LED is active (if selected). The blower can be adjusted while the DEFROST function is active. I W 42-14-08 Additional Outside Temperature Influence for DEFROST The corrected setpoints are increased in accordance with the curve above Heat exchanger temperature is brought up to maximum value. Controlled DEFROST function: Outside temperature > - 5 2 C The corrected setpoints are increased in accordance with a curve above. The heat exchanger setpoints are increased to at least 30 2 C. 39 E65 IHKA Reactions to Termination of DEFROST Function When the DEFROST function is active, only the rear window defroster, A/C functions and the temperature settings can be changed without switching off the DEFROST function. The DEFROST function is deactivated by pressing any button (except: temperature control knob, rear window defroster and REST buttons). When the DEFROST function is terminat¬ ed by pressing the DEFROST button, the control panel settings (stored in memory) are reactivated. A recirculated airfunction activated priorto DEFROST is deactivated, because recirculation and automatic A/C mode cannot be activated at the same time. This measure prevents the windows from fogging when the DEFROST function is switched off and further assisted by a delayed closure of the defroster flap. If the system is coded fora hot climate, the recirculated airfunction is stored in memory along with the other settings (if selected prior to the DEFROST function). Solar Sensor Effect The solar sensor allows the IH KA to compensate for sunlight that affects the temperature inside the vehicle. The solar sensors have an effect on air conditioning control. An increase in sunlight produces a shift in the functions listed below. The effect is opposite at night or when the vehicle enters a tunnel. The solar sensor consists of two photo resistors (left and right), which register the varying intensity of the light rays. The sensorsignals are interpreted in the solar sensor module and output to the IH KA control module (voltage range from 0 to 5V). The effect of the solars sensor separately affect the driver's and passenger's side to influ¬ ence the following air conditioning components/functions: Blower: The blower control curve is shifted (increased airflow compensation) Air stratification: The stratification temperature is shifted (increased temperature com¬ pensation) Flaps: The angle of the virtual flap is corrected (increased airflow/temperature compen¬ sation) 40 E65 IH KA Rear Window Defroster (HHS) Pressing the HHS button activates the rear window defrosting and the function LED illumi¬ nates. The system is deactivated by pressing the button fora second time, or automatically when the defrosting period (10 or 17 minutes) expires. Pressing the button during cyclic operation starts the post-defrosting phase (5 minutes). The HHS function is independent of the other button activated functions of IH KA with the exception of the "OFF" function. Defrosting Phase: After KL15 is switched "ON", the time period to optimize the rear win¬ dow defrosting is set as follows: Outside Temperature Heating Period (,Defrosting Phase) >-15 2 C 10 minutes <-15 2 C 17 minutes The function LED remains on for the duration of the heating period. Cyclic operation: The defrosting phase is followed by cyclic operation with 1/4 power for 30 minutes. This is cancelled by switching KL15 "OFF". 3 seconds ON / 9 seconds OFF. The function LED remains OFF during cyclic operation. Reactivation: If the rear window does not remain clear during cyclic operation, pressing the button again activates the defroster at full power for another 5 minutes. The function LED lights up. This post-defrosting phase is followed by cyclic operation. As of priority level 5 of the K-CAN message, low-voltage cutout by the power module is possible (protection effect of the power module). The HHS is controlled by the IH KA con¬ trol module. Fault handling KL50 The communication defect "KL50 logically on" bus message will shut down the rear win¬ dow defrosting and the duration of the KL50 active state is monitored. After 30 seconds of "physically on" this status is considered invalid and no fault message is entered in memo¬ ry. The function will be "logically off" and the HHS circuit remains inactive. 41 E65 IH KA Rear Window Defrosting - ON/OFF Criteria During Starting During starting (KL50 active), the rear window defrosting is "OFF". The status of the rear window defroster is transmitted by the IF! KA control module overthe K-CAN bus because: The power module switches the heated rear window on and off. The door modules control the outside mirror heating parallel with activation of the rear window defrosting. The navigation system requires the current flow status of the rear window (effects of the magnetic field). Wiper Parked Zone Heating In order to prevent the wiper blades freezing to the glass at low outside temperatures, the wiper parked zone heating is activated depending on the outside temperature. < 3 2 C Wiper parked zone heating ON > 6 2 C Wiper parked zone heating OFF Low voltage cutout of the wiper parked zone heating by the power module is possible. Switching conditions for shutdown are applied as of priority level 5 (K-CAN message). OFF Function The OFF Function is activated by pressing the left air volume control knob. The functions switched OFF (current status is saved) when the button is pressed are: Function LED in OFF button comes on, all others off OFF at Control Display All flaps to 0% Refrigerant system switched off Blower off Auxiliary water pump off Temperature control switched off Interior sensor blower continues to run Sensor value is retained Water valves receive power to maintain the closed position 42 E65 IH KA Recirculated Air / AUC / Auto Recirculated Air The RECIRCULATED AIR/AUC button has two functions. Changeover from RECIRCULATED AIR to AUC and vice verse Switch off RECIRCULATED AIR/AUC function (fresh air mode). FI 42-14-09 Changeover from fresh air mode to AUC or RECIRCULATED AIR: RECIRCULATED AIR /AUC Button Function Press once AUC function is activated - AUC LED "ON" and RECIRCULATED AIR LED "OFF" Press twice RECIRCULATED AIR function is activated - AUC LED "OFF" and RECIRCULATED AIR LED "ON" Press three times Return to fresh air mode - AUC and RECIRCULATED AIR LEDs both "OFF" To avoid whistling noises from the IH KA, closure of the fresh air flap is delayed for 0.5 sec and the stepper (MUX) motor for the recirculated air flap is activated. Recirculated Air Mode The recirculated air function can be used to preserve the air quality inside the cabin in sit¬ uations of poor outside air, when the vehicle is stopped in traffic, or when driving through tunnels. The recirculated air function is activated when the RECIRCULATED AIR/AUC but¬ ton on the control panel is pressed or when AUC detects a recirculated air condition. The fresh air flap closes within a maximum of 1 second; the recirculated air flap opens in approximately 4 seconds. The recirculated air function is not saved before the control module enters sleep mode, the function is not active following a reset. Note: When in the recirculated air mode, the air conditioning is not automatically activated. 43 E65 IH KA Automatic Recirculated Air Control (AUC) The IHKA measures air quality by analyzing the AUC-2 sensor signal. The AUC-2 sensor provides a PWM signal corresponding to the noxious-gas content. The sensor is provided 5V to activate the heating circuit (approx. 500 - 800 mW). Each time the vehicle is started, the fresh air position is actuated for 30 seconds to allow proper sensor heating. Sleep mode does not cancel the AUC function. Relative humidity inside the car can increase during a recirculated air phase, because the proportion of fresh air is low. This can cause the windows to fog, therefore recirculation in the AUC function is limited. The limitation time depends on whether the system is in heat¬ ing or air conditioning mode: Heating mode - The recirculating airtime period is limited to 4 minutes at outside tem¬ peratures > 6 2 C and is followed by 1 minute of fresh air. A/C mode - The recirculating airtime period is limited to 12 minutes at outside temper¬ atures > 6 2 C and is followed by 1 minute of fresh air. Automatic Recirculated Air This special function rapidly cools the interior of the vehicle. When the occupant requests maximum cooling power from the air conditioning, cool air from inside the cabin is drawn back through the evaporator again. This results in a quicker temperature drop inside the vehicle. This function initially operates for 12 minutes in the full recirculation air mode and then in partial recirculation air mode (fresh air 30% / recirculated air 100%). If this function is can¬ celled within the initial 12 minutes and reactivated, the function operates in the partial recir¬ culation air mode. The automatic recirculated air function is switched ON and OFF accord¬ ing to the following: ON OFF A/C mode selected and the variable (Y) < -20% A/C mode is terminated The variable (Y) > -5% 44 E65 IHKA Stationary Functions Principle of Operation The IHKA will operate features (when programmed) to enhance cabin comfort based on exiting heating and air conditioning systems and components. The IHKA Stationary Functions include: Residual Heat (rest) and Parked-car Ventilation. Residual Heat The Residual Heat (rest) function uses the residual engine heat after it is switched off to heat the passenger compartment. When the REST button is pressed, the Residual Heat func¬ tion is activated when KL15 is switched "OFF" and KLR is "ON". The auxiliary water pump is activated to circulate the hot coolant. The maximum "ON" time is 15 minutes. The Residual Heat function active when: REST button is pressed Outside temperature < 15 2 C Engine coolant temperature is > 70 2 C Ignition switch is in position R (KL15 OFF) 42 - 14-13 15 minutes has not elapsed since KL15 was switched "OFF" This function is deactivated when KL15 is switched "ON". When KLR is "ON", the AUTO buttons can also be pressed. The AUTO function is cancelled when KLR is switched "OFF", but the Residual Heat function will still remain active. Settings with "ignition Lock in Position R": Control panel remains active Temperature can be controlled Flap program available Blower speed adjustable Function lighting ON DEFROST, HHS, RECIRCULATED AIR/AUC and M AX-AC functions are not active 45 E65 IHKA Settings with the "Ignition OFF": Control panel is inactive Temperature control is held Flap program and blower setting of independent heating are held REST function lighting is active Parked-car Ventilation (SL) The Parked-car Ventilation blows ambient air into the passengercompartmentto lowerthe interior temperatures. The air enters the passenger compartment through the vent outlets in the instrument panel, which can be adjusted for both direction and flow (must be open for the system to operate). The system remains on for 30 minutes. The system can be switched on and off manually. The outside temperature must be > 50 C to activate this function. Using the Control Display, the Parked-car Ventilation function has 2 control options: Direct (manual) operation and Timer programming. Activating and Deactivating Manually: Ignition in position "KLR" Select "Indep. vent." on the second page of the "Climate" menu and confirm to activate Select "Indep. ventil." a second time and confirm to deactivate Timer Programming (two available times): Ignition in position "KLR" Select "Indep. vent." on the second page of the "Climate" menu and confirm Select "Set timel" / "Set time 2" and confirm Enter the desired time by turning the Con¬ troller and press to confirm 46 E65 IH KA 42-14-22 To Activate Timer: The Parked-car Ventilation is only available for activation within the subsequent 24 hours. After this the time will have to be reconfirmed. Select "Switch time 1" / "Switch time 2" and confirm 42-14-23 Terminal R "ON" (Control Panel is Active): Temperature control OFF (water valves closed) Flap program manually selectable Blower manually adjustable Function lighting ON Function buttons not active Terminal 15 "OFF" (Control Panel is Inactive): Temperature control: OFF (water valves closed) Flap program (0% = flap closed / 100% = flap open) - Warm air left and right 100% - Recirculating air 0% - Defrosting 0% - Footwell left and right 0% - Cold air left and right 100% - Rear seating area left and right 0% - Fresh air 100% - Blower set to 50% Function lighting OFF Note: The stationary functions are registered with the power module and are subject to deactivation bythe powermodule (priority leverconsumershutdown >6). The power mod¬ ule continuously monitors the battery state of charge while the Parked-car Ventilation func¬ tion is active. When the power module issues the shutdown signal forthe independent con¬ sumers, the IH KA will shut down the Parked-car Ventilation and it will not be reactivated. The IH KA will send a CAN message "status air conditioner Parked-car Ventilation" with the "INDEPENDENT VENTILATION not active" information to the Control Display. The Control Display responds by updating the on screen display. 47 E65 IH KA Non-Air Conditioning Functions Rear Window Roller Blind Control The IHKA controls the roller sun blind for the rear window and provides the OPEN/CLOSED information to the side window roller sun blinds. Principle of Operation The rear window roller blind is controlled by K-CAN messages sent by one of the door modules. The IHKA distinguishes between short and long actuation of the button. Short actuation of the button (< 750 ms) will cause the rear window roller blind to be acti¬ vated. If the button is pressed longer, a request is sent to the door modules to move the side window roller blinds in the same direction as the rear window roller blind. When the motor of the rear window roller blind is stopped short, the motor will move in the opposite direction (OPEN or CLOSE), depending on the previous detected limit position. The direction of motor rotation is reversed when the button is pressed while the motor is in operation. The motor continues to receive the drive signal until it stops. The first time the button is pressed after the engine is started (and KLR active), the motor will attempt to move the roller blind down, because the current position is not known. If the motor immediately blocks, the direction of rotation is reversed. To protect the motor, the drive signal is cancelled after 15 seconds (or current draw exceeds 8 amps). Actuation and Fault Recognition The illustration shows the motor of the rear window roller blind. S - Switches in doors TM - Door module CAS - Car Access System K CAN P - K bus periphery K CAN S - K bus system mC - Micro-controller ECU - IHKA control module D - Diagnosis output S1...S4- Electronic switches A - Rear window roller blind "OPEN" signal B - Rear window roller blind "CLOSED" signal 48 E65 IHKA The following faults can be recognized: Short circuit to B+ or open circuit: A fault is detected as long as the motor is actuated and the current is below the threshold. The motor is de-energized. Short circuit to ground: A fault is detected when one of the outputs is actuated and the current is above the threshold. The motor is de-energized. Excessive temperature: The internal temperature monitor deactivates the outputs. Overvoltage, undervoltage: The outputs are switched off in response to overvoltage or undervoltage. Notes: 49 E65 IHKA Coding The following coding information is factored into the IHKA control module: Vehicle type variants Engine versions Specifications for national markets Special equipment Control module variants (independent heating, RHD/LHD cars) The coding data is uploaded to the memory (EEPROM) of the IHKA control module, but is not active until the control unit has been reset. Control Module Identification The data written into the memory chip for control module identification is BMW part number BMW control module version number BMW coding index BMW diagnosis index BMW variant number Manufacturer's date of production Overview of B M W control module versions: Version for IH KA M anufacturer IH KA High without roller sun blind IHKA High with roller sun blind M anufacturer's catalogue of messages Manufacturer's software version Manufacturer's standard core version Manufacturer's reserve BMW change index BMW test stamp Control Module Number 03 04 Key Memory The custom settings of four different radio control keys can be saved in memory (EEPROM) after KL15 is switched "OFF". One of these four sets of settings is reactivated when KL15 is re-energized with the corresponding key. The last setting is activated either when the engine is started with the workshop key or if the information for the key number is incor¬ rect. The information for the key number is sent as a K-CAN message. 50 E65 IH KA Following a reset (KL15), the IHKA sends a message to the CAS requesting what key is currently in the initialization phase. Driver specific data is stored in memory blocks (EEP¬ ROM) for the total of four distinctive radio control keys. When one of these radio control keys is used, the appropriate memory block is called and the contained settings are activated. A fifth memory block contains default settings (in case a valid key is not recognized). The following data is stored in each of the five memory blocks: Temperature, left Air distribution program, left Air distribution, bottom left Air distribution, top left Blower, right Air stratification, right Air distribution, middle right Blower, left Air stratification, left Air distribution, middle left Temperature, right Air distribution program, right Air distribution, bottom right Air distribution, top right Active function: Always saved: AUC, AC, OFF Can be activated by coding: - Start with AUTO - Start with AC - Higher/lower blower characteristic Vehicle Memory Vehicle M emory includes all actions permanently saved in the IF! KA before the control mod¬ ule enters sleep mode and are reactivated after a reset (KL15). Saving Control Panel Status Terminal 15 ON, engine stopped. Each change to the control panel settings is saved approximately 1 second later in the control module. Terminal 15 ON, engine running. Each change to the control panel settings is saved approximately 10 seconds later in the control module. DEFROST, MAX AC, RECIRCU¬ LATED AIR and HHS are cleared when the consumer is switched off. 51 E65 IHKA Exception: Hot-climate version (can be coded). The RECIRCULATED AIR or MAX AC func tion, if activated before shutdown, is saved with the other settings. Coding Variants for Control Panel Functions Hot-climate version. When this version is coded the recirculated air function (if active) it is saved to memory (EEPROM)along with the otherdata when the control module enters sleep mode and is immediately available the next time the engine is switched on. Off lock. When this version is coded the OFF function is deleted when the control mod¬ ule enters sleep mode, the next time the engine is switched on the functions active before the OFF button was pressed are automatically reactivated. Automatic variants and automatic air stratification. The IHKA offers three variants for handling the AUTO function. There are also three different modes of setting air stratifi¬ cation to 50% when the AUTO function is switched on. Custom Settings The INDIVIDUAL program (EEPROM) can be used to save a data set with the following user-configurable flap settings for each side: Air distribution, head Air distribution, chest Air distribution, feet The data sets forthe INDIVIDUAL program are saved when the "NO PROGRAM" option is active and the memory button is pressed. The flap position settings are reactivated as soon as the user selects the "INDIVIDUAL" setting on the Control Display. Power Module Influence The power module uses the CAN message (power management) battery voltage signal "Control peak-reduction priority" to control consumershutdown by priority levels. The IH KA system responds to these priority signals by implementing the following measures: Priority 6 measures - Wiper parked zone heating OFF - Rear window defrosting OFF (applies to normal operation only, not in cyclic operation) 52 E65 IHKA Priority 5 measures - Wiper parked zone heating OFF - Rear window defrosting OFF (applies to normal operation, not in cyclic operation) Priority 4 measures - Blower set to max. 50% Priority 1 measures - Wiper parked zone heating OFF - Rear window defrosting OFF (applies to normal operation, not in cyclic operation) - Blower set to max. 25% (at this time the blower is shut down) When the "Status of independent consumers" is received = SHUTDOWN - Parked-car Ventilation OFF - Residual heat OFF Note: The DEFROST function always has 100% blower power available (safety relevant function). Sleep / Wait / Power Down Modes Sleep Mode To achieve the IH KA control module required standby current consumption (< 100 mA), network management forces it to enter sleep mode by isolating it from terminal 30. Wait Mode Conditions for wait mode: The control module run on time must be expired, 2 run on times are possible. Run on time of the control unit Terminal 15 Conditions for Residual Heat 3 minutes OFF not satisfied 15 minutes OFF satisfied The run on time for the water valves must be expired (fuel station effect can be coded) The control module enters a wait routine and is de-energized when all run on timers have timed out. Individual Sensor Values / Actuator Outputs Interior temperature sensor Heat exchanger temperature sensor Evaporator temperature sensor Ventilation temperature sensor Pressure sensor The pressure sensor outputs a voltage that to 4.6 V range). The refrigerant compressor Failsafe value: 20 2 C Failsafe value: 55 2 C Failsafe value: 2 2 C Failsafe value: 20 2 C Voltage supply: 5 V ±0.25 V Output voltage: 0 V...5 V linear to the refrigerant pressure (from 0.4 V switched off if pressure is excessive. Solar sensor Voltage supply: 5 V ±0.2 V Output voltage: 0 V...5 V AUC-2 sensor Voltage supply: 5 V ±0.25 V Output voltage: 0 V to 5 V Refrigerant compressor control valve Resistance of control valve at +20 2 C: 10.6 W ±0.5 W Resistance of control valve at +70 2 C: 14.5 W ±0.5 W Auxiliary water pump Switch on current: Rated current: approx. 5.0 A/100 ms 1.5 A Fresh air flap / rapid action motor 8 ohms ±7% (500 Hz) Bus stepper motors 100 ohms (200 Hz) 54 E65 !HKA Review Questions 1. List the gasses detected by the AUC-2 sensor. 2. Explain how the refrigerant compressor output is varied 3. List the refrigerant compressor "Run In" procedure 4. Where is the blower motor and blower control module located 7 5. What are the "M aster" function controls on the control panel 7 6. Explain the "Y" factor. 7. How is the temperature increased during air conditioning operation 7 8. List the functions that apply to heater operation when the coolant is cold 55 E65 IHKA