GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you perform the HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, perform Recalibrate all Motors in instrument panel module Special Function/Miscellaneous Tests.
  4. Select display DTC function in instrument panel module.

Does the scan tool display any DTCs?

Go to DTC Table

Go to Step 3

3

Was the customer complaint in A/C mode operation?

Go to Cooling Insufficient - Air Conditioning (A/C) System

Go to Step 4

4

Does the customer need to change the set temperature frequently to maintain comfort?

Go to Set Temperature Requires Frequent Adjustment

Go to Step 5

5

  1. Start the engine.
  2. Verify all the instrument panel outlets are open.
  3. Operate the system. Refer to the appropriate procedure:

Does the system operate properly?

Go to Step 6

Go to Symptoms

6

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, adjust the Temperature Offset in instrument panel module Special Function/Set Options as needed.

Did you complete the repair?

Go to Step 7

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7

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2