Control Module
IHKR1 CONTROL MODULE
The control module slides into a bracket at the forward, lower portion of the IHKR1 housing assembly.
The module contains the electronics used to process information furnished by the system sensors, switches and other input sources. The module also contains a non-volatile read- only-memory (ROM) where IHKR system programmed operating instructions are stored.
The control module takes the input information, processes it, and controls:
- Blower speed
- Air intake flaps (fresh/recirculating)
- Footwell air distribution flaps
- Mixing flap position
- Heater core temperatures
- Auxiliary coolant pump
- Evaporator temperature
- Auxiliary cooling fan
The control module can also detect faults in most of its input/output circuits and devices, and stores these fault codes in its memory. The fault codes can be read using the BMW Diagnosis & Information System (DIS).
The IHKR1 control module memory is volatile; any fault codes stored there are erased about 2-3 minutes after the ignition switch is turned to "Off."
Troubleshooting Tip: An intermittent failure may be the cause of poor IHKR system performance, but the failure may occur infrequently or under unusual operating conditions. Successful diagnosis will require that, when the failure occurs, the vehicle should be driven directly to the dealership and the ignition should not be switched off before fault codes are retrieved. The service advisor should coordinate this with the customer.