GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 SSR 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Diagnostic System Check - HVAC Systems - Manual

Test Description

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

  1. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.

    2.

  2. This step determines if the powertrain control module (PCM) has set DTCs which may affect HVAC operation are present.

    3.

  3. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.

    4.

  4. If there are HVAC control module DTCs present, then the LEDs for the A/C request switch, recirculation switch or the rear defrost switch will flash indicating a current DTC.

Step

Action

Yes

No

1

Did you review A Diagnostic Starting Point - Heating, Ventilation and Air Conditioning?

Go to Step 2

Go to Diagnostic Starting Point - Heating, Ventilation and Air Conditioning

2

Install a scan tool.

Does the scan tool power up?

Go to Step 3

Go to Scan Tool Does Not Power Up in Data Link Communications

3

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to establish communication with the powertrain control module (PCM).

Does the scan tool communicate with the PCM?

Go to Step 4

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

4

Select the Powertrain Control Module display DTCs function on the scan tool.

Does the scan tool display any DTCs?

Go to Step 5

Go to Step 7

5

Does the scan tool display any DTCs which begin with a "U"?

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

Go to Step 6

6

Does the scan tool display any DTCs that are associated with the charging system?

Go to Diagnostic Trouble Code (DTC) List in Engine Electrical

Go to Step 7

7

Does the scan tool indicate DTC P0530 is current?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 8

8

Perform the Diagnostic Trouble Code (DTC) Displaying procedure.

Do the LEDs for the A/C request switch, recirculation switch and the rear defrost switch flash repeatedly with no interruption?

Go to Symptoms - HVAC Systems - Manual

Go to Diagnostic Trouble Code (DTC) List