TABLE OF CONTENTS Subject Page INPUTS Power and Ground Inputs.2 Starting Input.4 Distribution / Air Delivery Seleotion .6 Temperature Seleotion .8 Blower Control.10 Stratified Air.12 Temperature Sensor Monitoring.14 Automatio Reoiroulated Air .16 Compressor Shut Off Signal .18 Refrigerant Pressure Sensor 20 POWER AND GROUND INPUTS Constant battery power supply (KL30) is neoessary for IHKA operation as well as memory (early systems). For the “battery draw test” see the repair manual referring to 16 minute “sleep” mode. Switohed ignition power (KL15) is required for IHKA operation when the ignition is in the “run” position. This allows the system to operate after the vehiole has been started (or lim¬ ited IHKA operation if the engine is not running). Grounds KL 31 Ground paths are provided to the IHKA to oomplete the oirouits of the inputs, prooessing, and output oontrol funotions. 2 NAME OF SIGNAL OR FUNCTION:_ Vehicle:_M.Y.:_ System:_DIS CD Version:_ What type of output signal provides current to activate this circuit? □switched Power □ Switched Ground □ Pulse Width Modulated (PWM) □ Linear Voltage □ Linear Resistance □ Digital Source: _ How will the control system react if this signal becomes impaired or lost ? Substitute Value? □ Yes □ No if yes what is it?_ Was a fault code(s) present with this defective signal/component? □ Yes □ No If yes what is (are) the specific code(s)?_ Does the DIS software provide a Status Display for this signal? □ Yes □ No If “yes”, what is it?_ Is “component activation” possible with this signal/function? □ Yes □ No If yes what does it do?_ Does this help you with diagnosis? □ Yes □ No Why?_ Pin Numbers: What is the control module pin number for the signal?_ Is there an associated ground wire? □ Yes □ No If “yes”, pin number?_ Are there any other signals/systems sharing the wire to consider? □ Yes □ No If “yes” are there faults present in that system as well? □ Yes □ No What is (are) the most suitable measurement(s) for this signal/component? □ Voltage □ Resistance □ Capacitance □ Inductance □ Temperature □ Current □ Pressure □ Scope Signal Range?:_Nominal Value?:_ Notes: 3 STARTING INPUT The starting (cranking KL50) input is monitored by the IHKAto “unload” consumers during engine cranking. This is a momentary signal that will cause the IHKA to deactivate heavy power oonsumers. This signal has a dedioated oirouit on E31/36 models, and is transmitted via BUS oommu- nioation on all other models. HOT AT ALL TIMES HOT AT ALL TIMES ■ HOT IN RUN AND START Q "H P90 I FRONT POWER DtSTRIBUTION BOX FUSE DETAfLS 0670.3 3T 4 31 4 35 4 31 4 LTJT I ❖ A115 AUTOMATIC CUMATE CONTROL MODULE 4 NAME OF SIGNAL OR FUNCTION:_ Vehicle:_M.Y.:_ System:_DIS CD Version:_ What type of output signal provides current to activate this circuit? □switched Power □ Switched Ground □ Pulse Width Modulated (PWM) □ Linear Voltage □ Linear Resistance □ Digital Source: _ How will the control system react if this signal becomes impaired or lost ? Substitute Value? □ Yes □ No if yes what is it?_ Was a fault code(s) present with this defective signal/component? □ Yes □ No If yes what is (are) the specific code(s)?_ Does the DIS software provide a Status Display for this signal? □ Yes □ No If “yes”, what is it?_ Is “component activation” possible with this signal/function? □ Yes □ No If yes what does it do?_ Does this help you with diagnosis? □ Yes □ No Why?_ Pin Numbers: What is the control module pin number for the signal?_ Is there an associated ground wire? □ Yes □ No If “yes”, pin number?_ Are there any other signals/systems sharing the wire to consider? □ Yes □ No If “yes” are there faults present in that system as well? □ Yes □ No What is (are) the most suitable measurement(s) for this signal/component? □ Voltage □ Resistance □ Capacitance □ Inductance □ Temperature □ Current □ Pressure □ Scope Signal Range?:_Nominal Value?:_ Notes: 5 DISTRIBUTION/ AIR DELIVERY SELECTION Distribution/air delivery selections are made at the control panel. On E31 models, the requested selection is monitored by the oontrol module whioh is remotely mounted. On all other models, the requested input seleotion is internally monitored beoause the oontrol panel and oontrol module are a oombined unit. The E31 oontrol panel is provided as an example. The IHKA oontrol module provides the power supply for the oontrol panel, then monitors the return voltage to determine the dis¬ tribution/air delivery seleotion. Notioe that the “AUTO” seleotion only illuminates the LED. The input is not monitored, therefore if no other seleotion is taken the system is in the auto program. 6 NAME OF SIGNAL OR FUNCTION:_ Vehicle:_M.Y.:_ System:_DIS CD Version:_ What type of output signal provides current to activate this circuit? □switched Power □ Switched Ground □ Pulse Width Modulated (PWM) □ Linear Voltage □ Linear Resistance □ Digital Source: _ How will the control system react if this signal becomes impaired or lost ? Substitute Value? □ Yes □ No if yes what is it?_ Was a fault code(s) present with this defective signal/component? □ Yes □ No If yes what is (are) the specific code(s)?_ Does the DIS software provide a Status Display for this signal? □ Yes □ No If “yes”, what is it?_ Is “component activation” possible with this signal/function? □ Yes □ No If yes what does it do?_ Does this help you with diagnosis? □ Yes □ No Why?_ Pin Numbers: What is the control module pin number for the signal?_ Is there an associated ground wire? □ Yes □ No If “yes”, pin number?_ Are there any other signals/systems sharing the wire to consider? □ Yes □ No If “yes” are there faults present in that system as well? □ Yes □ No What is (are) the most suitable measurement(s) for this signal/component? □ Voltage □ Resistance □ Capacitance □ Inductance □ Temperature □ Current □ Pressure □ Scope Signal Range?:_Nominal Value?:_ Notes: 7 TEMPERATURE SELECTION Temperature selections are made via thumbwheels (early systems), and rocker switches (later systems). On E31 models, the requested temperature selection is monitored by the control module which is remotely mounted. On all other models, the requested input selec¬ tion for temperature is internally monitored because the control panel and control module are a combined unit. The E31 control panel is provided as an example. The IHKA control module provides the power and ground supply for the control panel potentiometers, then monitors the return voltage from the potentiometers to determine the temperature selection. MIXJNQ SWITCH AUTOMATIC HEATINO/AC CONTOOL MODULE (IHKA) 8 NAME OF SIGNAL OR FUNCTION:_ Vehicle:_M.Y.:_ System:_DIS CD Version:_ What type of output signal provides current to activate this circuit? □switched Power □ Switched Ground □ Pulse Width Modulated (PWM) □ Linear Voltage □ Linear Resistance □ Digital Source: _ How will the control system react if this signal becomes impaired or lost ? Substitute Value? □ Yes □ No if yes what is it?_ Was a fault code(s) present with this defective signal/component? □ Yes □ No If yes what is (are) the specific code(s)?_ Does the DIS software provide a Status Display for this signal? □ Yes □ No If “yes”, what is it?_ Is “component activation” possible with this signal/function? □ Yes □ No If yes what does it do?_ Does this help you with diagnosis? □ Yes □ No Why?_ Pin Numbers: What is the control module pin number for the signal?_ Is there an associated ground wire? □ Yes □ No If “yes”, pin number?_ Are there any other signals/systems sharing the wire to consider? □ Yes □ No If “yes” are there faults present in that system as well? □ Yes □ No What is (are) the most suitable measurement(s) for this signal/component? □ Voltage □ Resistance □ Capacitance □ Inductance □ Temperature □ Current □ Pressure □ Scope Signal Range?:_Nominal Value?:_ Notes: 9 BLOWER CONTROL Blower control operation Is In operation with the Ignition switched on (KL15). The blower speed Is controlled by regulating (varying) the ground circuit through the use of transistors (final stage unit). The IHKA control module determines the appropriate blower speed using these primary Inputs: • Blower control thumbwheel/rocker switch Inputs • The “Y-factor” The On E31 models, the requested blower speed selection Is monitored by the control module which Is remotely mounted. On all other models, the requested Input selection for blower speed Is Internally monitored because the control panel and control module are a combined unit. The E31 control panel Is provided as an example. The IHKA control module provides the power and ground supply for the potentiometer, then monitors the return voltage to deter¬ mine the blower speed selection. 10 NAME OF SIGNAL OR FUNCTION:_ Vehicle:_M.Y.:_ System:_DIS CD Version:_ What type of output signal provides current to activate this circuit? □switched Power □ Switched Ground □ Pulse Width Modulated (PWM) □ Linear Voltage □ Linear Resistance □ Digital Source: _ How will the control system react if this signal becomes impaired or lost ? Substitute Value? □ Yes □ No if yes what is it?_ Was a fault code(s) present with this defective signal/component? □ Yes □ No If yes what is (are) the specific code(s)?_ Does the DIS software provide a Status Display for this signal? □ Yes □ No If “yes”, what is it?_ Is “component activation” possible with this signal/function? □ Yes □ No If yes what does it do?_ Does this help you with diagnosis? □ Yes □ No Why?_ Pin Numbers: What is the control module pin number for the signal?_ Is there an associated ground wire? □ Yes □ No If “yes”, pin number?_ Are there any other signals/systems sharing the wire to consider? □ Yes □ No If “yes” are there faults present in that system as well? □ Yes □ No What is (are) the most suitable measurement(s) for this signal/component? □ Voltage □ Resistance □ Capacitance □ Inductance □ Temperature □ Current □ Pressure □ Scope Signal Range?:_Nominal Value?:_ Notes: 11 STRATIFIED AIR The request for air temperature stratification is made by a thumbwheel located in the front center face vent outlet and the rear passenger console outlet (if equipped). The thumbwheel potentiometer receives power and ground from the IHKA control module which also mon¬ itors the variable return voltage. In addition, the rear console outlet contains a micro-switch (on/off request) that signals to the IHKA control module to allow air flow to the rear console. Heating A A/C ccritrol module REAR STRATIFICATIOM POTENTIOMETER 12 NAME OF SIGNAL OR FUNCTION:_ Vehicle:_M.Y.:_ System:_DIS CD Version:_ What type of output signal provides current to activate this circuit? □switched Power □ Switched Ground □ Pulse Width Modulated (PWM) □ Linear Voltage □ Linear Resistance □ Digital Source: _ How will the control system react if this signal becomes impaired or lost ? Substitute Value? □ Yes □ No if yes what is it?_ Was a fault code(s) present with this defective signal/component? □ Yes □ No If yes what is (are) the specific code(s)?_ Does the DIS software provide a Status Display for this signal? □ Yes □ No If “yes”, what is it?_ Is “component activation” possible with this signal/function? □ Yes □ No If yes what does it do?_ Does this help you with diagnosis? □ Yes □ No Why?_ Pin Numbers: What is the control module pin number for the signal?_ Is there an associated ground wire? □ Yes □ No If “yes”, pin number?_ Are there any other signals/systems sharing the wire to consider? □ Yes □ No If “yes” are there faults present in that system as well? □ Yes □ No What is (are) the most suitable measurement(s) for this signal/component? □ Voltage □ Resistance □ Capacitance □ Inductance □ Temperature □ Current □ Pressure □ Scope Signal Range?:_Nominal Value?:_ Notes: 13 TEMPERATURE SENSOR MONITORING Several different temperature sensors provide inputs to the IHKA oontrol module. As previ¬ ously oovered, they are the NTC type. The IHKA oontrol module provides the power and ground paths. The module also monitors the oirouit voltage variation to determine temper¬ atures. This test applies to the following sensors: • Interior (internal oon- trol module oirouit for all models exoept E31) • Ambient (dedioated for E31/36, all other models supplied from Instrument oluster via K-bus) • Heater oore • Evaporator • Faoe vent (E38 only) 14 NAME OF SIGNAL OR FUNCTION:_ Vehicle:_M.Y.:_ System:_DIS CD Version:_ What type of output signal provides current to activate this circuit? □switched Power □ Switched Ground □ Pulse Width Modulated (PWM) □ Linear Voltage □ Linear Resistance □ Digital Source: _ How will the control system react if this signal becomes impaired or lost ? Substitute Value? □ Yes □ No if yes what is it?_ Was a fault code(s) present with this defective signal/component? □ Yes □ No If yes what is (are) the specific code(s)?_ Does the DIS software provide a Status Display for this signal? □ Yes □ No If “yes”, what is it?_ Is “component activation” possible with this signal/function? □ Yes □ No If yes what does it do?_ Does this help you with diagnosis? □ Yes □ No Why?_ Pin Numbers: What is the control module pin number for the signal?_ Is there an associated ground wire? □ Yes □ No If “yes”, pin number?_ Are there any other signals/systems sharing the wire to consider? □ Yes □ No If “yes” are there faults present in that system as well? □ Yes □ No What is (are) the most suitable measurement(s) for this signal/component? □ Voltage □ Resistance □ Capacitance □ Inductance □ Temperature □ Current □ Pressure □ Scope Signal Range?:_Nominal Value?:_ Notes: 15 AUTOMATIC RECIRCULATED AIR (AUC if equipped) The IHKA control module uses data from the AUC sensor to determine whether reolroulat- Ing air mode Is neoessary. The AUC sensor samples ambient air that has entered the engine oompartment. The sensor oontalns a gas sensor, whioh measures the level of oxidizable gasses In the air. These Inolude hydrooarbons, NOx, SOx, and CO. The IHKA oontrol module monitors the ohange In the voltage signal as these gasses Influ- enoe the sensor. The seoond olroult shown Is a heating olroult whioh enhanoes the sensor’s reaotlon time. When starting the vehlole, fresh air Is always supplied for 90 seoonds due to the AUC sensor heat-up time. Heating and A/C control module Automatic air recirculation sensor Heating and A/C control module 16 NAME OF SIGNAL OR FUNCTION:_ Vehicle:_M.Y.:_ System:_DIS CD Version:_ What type of output signal provides current to activate this circuit? □switched Power □ Switched Ground □ Pulse Width Modulated (PWM) □ Linear Voltage □ Linear Resistance □ Digital Source: _ How will the control system react if this signal becomes impaired or lost ? Substitute Value? □ Yes □ No if yes what is it?_ Was a fault code(s) present with this defective signal/component? □ Yes □ No If yes what is (are) the specific code(s)?_ Does the DIS software provide a Status Display for this signal? □ Yes □ No If “yes”, what is it?_ Is “component activation” possible with this signal/function? □ Yes □ No If yes what does it do?_ Does this help you with diagnosis? □ Yes □ No Why?_ Pin Numbers: What is the control module pin number for the signal?_ Is there an associated ground wire? □ Yes □ No If “yes”, pin number?_ Are there any other signals/systems sharing the wire to consider? □ Yes □ No If “yes” are there faults present in that system as well? □ Yes □ No What is (are) the most suitable measurement(s) for this signal/component? □ Voltage □ Resistance □ Capacitance □ Inductance □ Temperature □ Current □ Pressure □ Scope Signal Range?:_Nominal Value?:_ Notes: 17 COMPRESSOR SHUT OFF SIGNAL (if applicable) The IHKA module monitors the full load input from the ECM. If the ECM deteots “full load” oonditions, it signals (KOREL) the IHKA oontrol module to disengage the A/C oompressor. The oonditions for full load are: • Vehiole speed less than 10 mph, and • Throttle is wide open or • Engine ooolant temperature is too high The oompressor is turned off for a maximum of 4 minutes (aotual duration differs per sys¬ tem). IHKA CONTROL PANEL/MODULE 18 NAME OF SIGNAL OR FUNCTION:_ Vehicle:_M.Y.:_ System:_DIS CD Version:_ What type of output signal provides current to activate this circuit? □switched Power □ Switched Ground □ Pulse Width Modulated (PWM) □ Linear Voltage □ Linear Resistance □ Digital Source: _ How will the control system react if this signal becomes impaired or lost ? Substitute Value? □ Yes □ No if yes what is it?_ Was a fault code(s) present with this defective signal/component? □ Yes □ No If yes what is (are) the specific code(s)?_ Does the DIS software provide a Status Display for this signal? □ Yes □ No If “yes”, what is it?_ Is “component activation” possible with this signal/function? □ Yes □ No If yes what does it do?_ Does this help you with diagnosis? □ Yes □ No Why?_ Pin Numbers: What is the control module pin number for the signal?_ Is there an associated ground wire? □ Yes □ No If “yes”, pin number?_ Are there any other signals/systems sharing the wire to consider? □ Yes □ No If “yes” are there faults present in that system as well? □ Yes □ No What is (are) the most suitable measurement(s) for this signal/component? □ Voltage □ Resistance □ Capacitance □ Inductance □ Temperature □ Current □ Pressure □ Scope Signal Range?:_Nominal Value?:_ Notes: 19 REFRIGERANT PRESSURE SENSOR (if applicable) The IHKA control module supplies the power and ground paths, as well as monitoring the variable voltage signal from the refrigerant pressure sensor (boated In the reoelver/dryer). Based on the refrigerant pressure, the IHKA module “antlolpates” the the start up torque of the A/C oompressor. If the pressure Is too low or high the oompressor will be deaotlvated. This Input Is also used to vary the auxiliary fan speed and transfers this Information on to the ECM via the K-bus. Ptwunin bv e 0 9 T 11 z 3 14 i 15 5 17 7 IB ft h 1S s 1 ia 31 11 35 13 23 13 iJ 15 Heating & A/C control module Refrigerant pressure sensor Meeting & A/C control module 20 NAME OF SIGNAL OR FUNCTION:_ Vehicle:_M.Y.:_ System:_DIS CD Version:_ What type of output signal provides current to activate this circuit? □switched Power □ Switched Ground □ Pulse Width Modulated (PWM) □ Linear Voltage □ Linear Resistance □ Digital Source: _ How will the control system react if this signal becomes impaired or lost ? Substitute Value? □ Yes □ No if yes what is it?_ Was a fault code(s) present with this defective signal/component? □ Yes □ No If yes what is (are) the specific code(s)?_ Does the DIS software provide a Status Display for this signal? □ Yes □ No If “yes”, what is it?_ Is “component activation” possible with this signal/function? □ Yes □ No If yes what does it do?_ Does this help you with diagnosis? □ Yes □ No Why?_ Pin Numbers: What is the control module pin number for the signal?_ Is there an associated ground wire? □ Yes □ No If “yes”, pin number?_ Are there any other signals/systems sharing the wire to consider? □ Yes □ No If “yes” are there faults present in that system as well? □ Yes □ No What is (are) the most suitable measurement(s) for this signal/component? □ Voltage □ Resistance □ Capacitance □ Inductance □ Temperature □ Current □ Pressure □ Scope Signal Range?:_Nominal Value?:_ Notes: 21