Test Description

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

1. Ensure to perform the HVAC diagnostic system check. If DTCs B0434, DTC B3764 and the auxiliary blower motor is always on, then the 5 volt reference circuit of the auxiliary HVAC door actuators is pulled low to ground. The DTC diagnostic must be performed to ensure circuit is tested.
5. This step tests for an internal failure of the rear seat audio (RSA) control module, or the auxiliary HVAC control module.
6. This step tests the 5 volt reference supplied by the auxiliary blower motor control processor.
7. This step tests for an internal failure of the front auxiliary HVAC control assembly.

Fig 1: Diagnosis Procedure Blower Motor Malfunction - Auxiliary (Step 1 To 6)
Courtesy of GENERAL MOTORS CORP.

Fig 2: Diagnosis Procedure Blower Motor Malfunction - Auxiliary (Step 7 To 16)
Courtesy of GENERAL MOTORS CORP.

Fig 3: Diagnosis Procedure Blower Motor Malfunction - Auxiliary (Step 17 To 22)
Courtesy of GENERAL MOTORS CORP.