Checking Causes Of No Self-Adjustment
Check and/or remedy the following if damper motor self-adjustment is interrupted or is not possible.
Start the engine (the generator (GEN) charges). Climate control unit (ECC) terminal #B3 receives a signal from the generator indicating that there is charging. This is to supply the damper motors with maximum power supply during adjustment. If the signal is missing, the adjustment is not permitted to start. Read off the "Generator D+" parameter. Check that the signal is being transmitted.
Switch off the engine. Start the engine again. If self-adjustment has been carried out in the current ignition cycle, the control module will not perform a new self-adjustment until the ignition has been switch off and the engine re-started. Try to perform self-adjustment again.
Read off the diagnostic trouble codes (DTCs). Carry out any fault-tracing according to the instructions.
Check that the control module power supply (terminal #B5) and power ground (terminal #A23) is OK.
Check that the position sensor circuit is OK for both the temperature damper motors.
Check the signals to control module terminals #A7, #A13 and #A22 for the right temperature damper motor.
Check the signals to control module terminals #A7, #A12 and #A22 for the left temperature damper motor.
Check that the damper, linkage, cam discs, damper motors etc are correctly installed and can move freely and smoothly to the limit positions. Check the damper motor shaft and its mounting in the damper spindle in particular for damage and cracks etc.
Other information:
- For information about signals, see Signal specification ECC
- To connect the breakout box, see Connection of breakout box ECC .
Do you want to try self-adjustment again?
- YES
Refer to Self-Adjustment Of The Damper Motor Limit Positions, ECC
- NO
Refer to Verification