Test Index (Start Here)

System Test Index:

These tests should be conducted if the cause of the fault is unknown, or if the selected interior temperature is not attained, or the air distribution flaps fail to open.

1. Verify that fuses 5, 7, and 12 or in operating order.
2. Verify that the aspirator blower for the interior temperature sensor is operating correctly. Testing and Inspection
3. Remove the ACC push-button control unit. Refer to COMPONENT REPAIR AND REPLACEMENT PROCEDURES.
4. Connect the Mercedes Benz socket box or equivalent to the cable harness. The ACC control unit remains disconnected until test 7.