TABLE OF CONTENTS Subject Page Introduction.2 Control Panels.3 Air Distribution Control.5 Rear Window Defrosterl.5 Components.6 Temperature Regulation - Heating.7 Temperature Regulation - Air Conditioning.9 Fan Speed Controi.11 IHKS Diagnosis.13 INKS System Diagnosis.14 Chart A: A/C Compressor Does Not Operate .17 Chart B: A/C Insufficient Cooling .18 Chart C: Insufficient Heating.20 Chart D: Compressor Ciutch Does Not Engage.21 Chart F: Blower Relay Test.23 Chart G: Insufficient Cooling/Heating Flap/Valve Test.24 Chart H: Air Intake.25 INTRODUCTION The heating/air conditioning systems of the E36/5 and /7 (318ti and Z3) were specifically designed for use in these models. The system is a so-called “controlled” system. The temperature and air distribution are controiied, NOT reguiated. The systems are called “INKS”. Translated from German, the acronym means, “Integrated Heating and Air Conditioning Controi.” Highlights of the IHKS system include: • Compact heater case design with microfilter for air iniet (318ti only). • Temperature control through air blending fiap. • Mechanicai air distribution control. • One fresh/recirc air flap stepper motor. • Four-speed resistor controlled blower motor. 2 CONTROL PANELS Control panels for the 318ti and Z3 systenns are similar. Each consists of rotary knobs and push button switches. The control panel Is integrated into the center console. 318ti ROTARY KNOBS Right = Air distribution control Middle = Temperature control Left = Fan speed control switch PUSH BUTTONS • Top = Rear window defroster - • Middle = A/C compressor request switch • Bottom = Recirculating air control button MUTE i SCO ■■■■ ■■■■ ■ ■ ■ ■ ■■■ ■ ■■■ J BAND • ANTI THEFT BMW m I DOLBY B NR M — 0 D + - E . PROG SCAN The air distribution and temperature control knobs are mechanically linked to cables that operate the internal flap levers. The fan speed switch controls the blower speed through a resistor pack. 3 ROTARY KNOBS PUSH BUTTONS • Bottom = Recirculating air control button • Top = A/C compressor request switch — • Right = Fan speed control switch • Middle = Temperature control - • Left = Air distribution control — 4 AIR DISTRIBUTION CONTROL The air distribution is totally dependent on the position of the rotary knob. It Is similar in operation to the E36 IHKR system. The defrost, face vent and footwell flaps are all controlled with a bowden cable and gear linkage mechanism. The knob rotates 360° to give the following air distribution: FULL BLEND OF BOTH BLEND OF BOTH FULL FOOTWELL FULL FAOE VENT REAR WINDOW DEFROSTER The rear window defroster is switched on through a relay when the control button button is pressed. It remains on until switched Off by the button or the ignition is switched Off. There is no timed operation for the rear window defroster. 5 COMPONENTS HOUSING The lightweight design of the INKS housing provides a strong, compact, integral structure for the INKS components. The Z3 and 318ti system housings are Identical In function but have differences in the following areas. • The Z3 has a dual squirrel cage blower wheel versus the single blower wheel of the 318tl. • The Z3 housing has a slightly shorter profile. • The Z3’s INKS control module Is mounted on the driver’s side of the housing versus the passenger’s side of the 318ti. • The Z3 does not utilize an air inlet microfilter like the 318tl. • The mounted angle of the heater core In the Z3 system is “flatter” In the housing compared with the 318ti. 6 318ti Housing TEMPERATURE REGULATION - HEATING Discharge air temperature in the heating mode is controlled by the air blending flap. The rotary temperature knob controls the air blending flap, which determines how much air passes through the heater core. Turning the knob clockwise will gradually Increase the temperature of the air discharged into the cabin. + WATER VALVE IS POWERED CLOSED WHEN IN MAX COLD 318 ti SHOWN (Z3 IS SWITCHED B+) AIR BLENDING FLV\P EVAPORATOR HEATER CORE WHEN DEFROST & VENTILATION FLAPS ARE BOTH CLOSED AIR IS DISTRIBUTED TO THE FOOT WELL VENTS (NOT ILLUSTRATED) CONDENSATE DRAIN CHANNEL 318ti Housing DRAIN OUTLET 7 WATER VALVE Water flow through the heater core is controlled by a water valve. The water valve is either open or closed. There is no pulsed regulation of the valve. The water valve is open except when the tennperature knob is in the full cold position. This is controlled by a microswitch mounted on the heater control panel. The microswitch provides either switched: • Ground in the 318ti or • Power in the Z3 HEATER CORE The single heater core unit has one coolant supply tube and one return tube. The heater core can be removed without removing the housing from the vehicle. Remove the retaining screws as shown in the illustration. Drain the coolant from the system and disconnect the hoses from the supply and return tubes. Slide the heater core from the housing. 8 TEMPERATURE REGULATION - AIR CONDITIONING Discharge air temperature in the A/C mode is also controlled by the air blending flap. The rotary knob controls how much air passes through the heater core. Compressor control Is a function of the IHKS control module and the Engine Control Module (ECM). When the “snowflake” button is pressed, the ECM is signaled for idle stabilization; it then switches the compressor On by activating the control side of the compressor relay. The ECM will switch the compressor Off when the IHKS control module senses that evaporator temperature has dropped to approximately 3°C (or under full load as with the previous ECM systems). EVAPORATOR EVAPORATOR TEMPERATURE SENSOR The evaporator temperature sensor is a long, thin probe which is inserted into the left side of the INKS housing. The sensor is a Negative Temperature Coefficient (NTC) thermistor, whose resistance varies according to temperature. The evaporator temperature sensor tip reaches several inches into the evaporator core, where an accurate measurement of the core’s temperature can be obtained. INKS CONTROL MODULE The INKS control module is mounted on the system housing: • Z3 on driver’s side • 318ti on the passenger’s side The INKS control module’s scope of function is to monitor the evaporator temperature sensor signal and notify the ECM to switch off the compressor if the evaporator is close to freezing temperature (3°C). EXPANSION VALVE The expansion valve of the INKS system Is accessible from inside the vehicle in the passenger’s footwell area. To access the expansion valve, a housing cover must first be removed. The expansion valve Is Installed in the INKS housing. Sound deadening putty is packed around the expansion valve to minimize noise. Remove the putty to access the mounting bolts. When reinstalling the valve, make sure a sufficient quantity of putty is packed around the expansion valve to prevent a future noise complaint. 10 FAN SPEED CONTROL 318ti Fan speed is controlled using a four-position switch and a resistor pack to vary blower motor voltage. The resistor pack is mounted on the heater case in the air stream for cooiing purposes. The resistor pack is accessibie from the engine compartment with the microfilter removed. To access the microfilters, remove the air inlet grille at the center of the cowl. Unscrew the air inlet bulkhead panel and plastic cover. Pull the bulkhead panel from engine compartment and remove the exposed microfilters. KL 15 FAN SPEED RESISTOR PACK BLOWER MOTOR INKS CONTROL MODULE r f TO FRESH AIR/ RECIRCULATING FLAP MOTOR The fan switch is the master controller for the system. In the 0 position, the A/C compressor is switched off, the recirc flaps are opened, and the fresh air flaps are closed. In fan speeds 1, 2 and 3, the blower motor’s speed is cut back with the resistor pack. In speed 4, the blower motor receives full battery voltage. The recirc LED over the button will remain On when the fan switch is Off to indicate the recirc mode. There is no possibility of fresh air in the cabin with the fan switch Off. The fresh air/recirc flaps are controlled with one motor. The fresh air flaps are open until the recirc button is pressed or the fan switch is switched Off. 11 The resistor pack in the Z3 INKS is located on the blower motor. It’s accessible from the engine compartment. Remove the blower motor cover. Unclip the resistor pack from the blower motor and pull outward. On the Z3, the fan switch controls only the fan speed. It has no influence on the recirculating air function as it does on the 318ti. The fresh air flaps remain open when the switch is in the 0 position, if the recirculating air or “snowflake” button Is pressed with the fan switch in the 0 position, the fan will automatically run at very slow speed. RESISTOR PACK BLOWER /""X MOTOR KL 15 FAN SPEED TO FRESH AIR/ RECIRCULATING FLAP MOTOR TO ENGINE CONTROL MODULE (COMPRESSOR ON REQUEST) INKS CONTROL MODULE 12 IHKS DIAGNOSIS The IHKS system is not connected to the diagnostic link. Conventionai troubieshooting methods are used for diagnosis/troubleshooting probiems with this system. The best diagnostic tool you can have is a thorough understanding of the system’s individual components and the way they work. You should know which inputs affect which outputs, and how the ECM and IHKS module will respond if an input is outside allowable values. Also, know how to use the resources available to you: • Electrical Troubleshooting Manuals (ETMs). • Service-Information Bulletins. • Diagnosis and Information System (DIS). Refer to the DIS for repair manual procedures, technical data, etc. • If insufficient cooling is the complaint, make sure the water valve is actually closing. Technician Tip: have an assistant turn the temperature knob from the Fuii Hot to the Fuii Coid position and back severai times. Use a stethoscope to iisten to the water valve, to make sure it is actuaiiy ciosing, and check temperature of heater hoses. • Check high-side and low-side pressures when the compressor is operating. • When leak checking, look for wet spots on the hoses or at fitting connections. 13 INKS CONTROL SYSTEM DIAGNOSIS start all diagnosis of the INKS control system with the “INKS Function Check.” The function check leads to a specific chart or test. Finish all diagnosis by repeating the “IHKS Function Check ” to ensure correct diagnosis. Some diagnostic procedures require the ignition switch to remain On for extended periods of time. Low battery voltage may result, causing incorrect voltage readings. If vehicle system voltage becomes low, connect a battery charger to the electrical system and apply a slow charge while testing. Most intermittent failure, check suspect circuits for: • Poor mating of connector halves or • Improperly formed or damaged terminals backed out. terminals. • Dirt or corrosion on the terminals. • Poor termlnals-to-wire connection 14 IHKS FUNCTION CHECK The following procedures check the IHKS control system. All the steps can be performed without using tools. Detailed diagnostic procedures follow the system check and are referenced in each step. Complete this check with the temperature outside the vehicle at 60° F or higher, and with the engine running. SET A/C CONTROLS NORMAL RESULT FOR DIAGNOSIS REFER TO: 1. “Snowflake” button: off. Fan speed control switch: 0. • Blower is not running. Symptom Table E 2. Air temperature control knob: full hot. Fan speed control switch: 1. Air distribution control knob: full footwell. • Blower runs at lowest speed. • Air flows from floor outlets. • Air flow becomes warm. Symptom Table E Chart G 3. Increase fan speed control switch from 1 to 4. • Increased air flow, at each step. Symptom Table E 4. “Snowflake” button: on. Air distribution control knob: full defrost. Air temperature control knob: full hot. • Air flows from windshield outlets. • Compressor turns on. • Air flow becomes warm. Chart D Chart G 5. “Snowflake” button: off. Air temperature control knob: full cold. Fan speed control switch: 4. Toggle the recirculating air control button on and off. • Air flows from the windshield outlets. • Blower noise increases when the recirculating air control button is on and decreases when it is off. Chart D Chart H 6. “Snowflake” button: on. Air distribution control knob: blend of footwell and face. Air temperature control knob: full cold. Fan speed control switch: 1. • Air flows from face and footwell outlets. • Compressor turns on. • Air flow becomes cold. Chart D Chart G 15 IHKS SYSTEM DIAGNOSIS 16 CHART A: A/C COMPRESSOR DOES NOT OPERATE 17 CHART B: A/C INSUFFICIENT COOLING 18 (Continued on next page) CHART B; A/C INSUFFICIENT COOLING (Cont.) (Continued from previous page) 19 CHART C: INSUFFICIENT HEATING 20 CHART D: COMPRESSOR CLUTCH DOES NOT ENGAGE • Do tests only when the outside temperature is above 16°C (60°F). (Continued on page 22) 21 CHART D: COMPRESSOR CLUTCH DOES NOT ENGAGE (Cont.) (Continued from page 21) (Continued from page 21) 22 SYMPTOM TABLE E: BLOWER CONTROLS SYMPTOM ACTION Blower runs continuously with fan speed control switch in position 0 (ignition switch on). Replace the blower switch. Blower does not run in one of the fan speed control switch positions 1,2, or 3. Disconnect the blower resistor assembly: measure the voltage at the corresponding terminal of the connector. If battery voltage is present, replace the resistor assembly. If not, troubleshoot the fan speed control switch and wiring to the resistor assembly. Blower does not run in position 4. Troubleshoot the fan speed control switch and the wiring to splice X906. Blower does not run in any speed. Refer to Chart F. CHART F: BLOWER RELAY TEST 23 CHART G: INSUFFICIENT COOLING/HEATING FLAP/VALVE TEST 24 CHART H: AIR INTAKE 25 Table of Contents BMW FEATURES Subject Page • Purpose of The System.02 -System Components • INKS Panel.03 • Control Panel Connections. 04 -Blower Settings •System Operation.05 -Flap Setting. 06 - Auxiliary Water Pump.06 -Temperature Control. 07 -Airconditioning. 07 -Idle Speed Compensation. 07 -Filling Station Effect. 07 -Characteristic Map Cooling. 08 -Defrost Functions. 08 -Rear Defogger. 08 -Program Selector Switch. 09 -Auxiliary Fan K-Bus Interface. 10 -K-Bus Interface.11 Revision Date: 12/00 IHKS - Heating and Air Conditioning Purpose of the System An integrated heating/air conditioning controi system (IHKS) is used in the Z8 to provide the driver and passanger a comfortabie atmosphere regardiess of conditions outside the vehicle. The heater/air conditioner is designed as an air-based controi. 6 actuator are used to distribute the air and controi the temperature. 64E52IHKSAIRFLOW0100 System Components The IHKS consists of the foliowing main components: • Eiectronic Control panel/module with integrated fresh air griile • Heater/air conditioner unit • Five actuator (bus stepper motors) for controliing the recirculated air, temperature mixing, defroster, face vent and foot-weii flaps • One actuator (high speed stepper motor) for controliing the fresh air flap • Electric shut-off water valve • Electric auxiliary water pump • Refrigerant pressure sensor • Evaporator temperature sensor • Rear window defogger relay • Series resistors for blower motor 2