SYSTEM OPERATION
The balance of the E46 IHKA system's features and operation carry over from the E36
including:
• Maximum defrost operation
• Rear window defogger operation
• Final stage blower control
• Road speed dependent fresh air flap operation
• Air distribution control
• Stepper motor calibration run
• Cold start interlock
DIAGNOSIS AND TROUBLESHOOTING
The "self diagnostics" of the IHKA control module monitors the status of inputs and outputs
of the system. If a fault is detected, it is initially entered in RAM and than in the EEPROM
when the ignition is switched off. If available, a replacement value will be activated when
various sensor faults are detected as with previous systems. A maximum of six faults can
be stored in the EEPROM when the ignition is switched off.
The E46 IHKA is connected to the diagnostic link via the K -Bus/instrument cluster. The
system uses the E46 "Fault Symptom Troubleshooting " procedures for troubleshooting
problems and faults with the system.
When troubleshooting problems with the E46 IHKA, it is important to note that because the
Car/Key Memory feature can change the functionality of the system, a review of the set-
ting should be performed prior to condemning a component as faulty.
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E46 Climate Control