GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The auxiliary mode doors cannot be adjusted.

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Recalibrate actuators. Refer to Actuator Recalibration .
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the DTC list in Rear HVAC/RSA.

Does the scan tool display DTC B0145, B0428, or B3531?

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

Go to Step 3

3

  1. Turn ON the ignition, with the engine OFF.
  2. Place the front auxiliary blower motor switch in each speed position.

Does the front auxiliary blower motor operate in any of the speed positions?

Go to Step 4

Go to Auxiliary Blower Motor Inoperative

4

Does the auxiliary blower motor operate at the desired speed?

Go to Step 5

Go to Auxiliary Blower Motor Malfunction

5

  1. Turn ON the ignition, with the engine OFF.
  2. Place the front auxiliary blower motor switch in the Rear position.
  3. With a scan tool, observe the Console Mode Door actual and the Mode Door Actual parameter in the Rear HVAC/RSA data list.
  4. Place the auxiliary mode switch from the floor position to the upper outlets position.

Does both the Console Mode Door and the Mode Door Actual parameters count value change?

Go to Step 8

Go to Step 6

6

Inspect for poor connections at the harness connector of the auxiliary HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 7

7

Replace the auxiliary HVAC control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 8

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8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2