GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2000 🢒 Grand Prix 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Diagnostic System Check

Test Description

The number(s) below refer to the step number(s) 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. The Powertrain Control Module will display DTCs if the A/C compressor reacts improperly to the request for cooling air.

Step

Action

Yes

No

1

Install a scan tool.

Does the scan tool power up?

Go to Step 2

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

2

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

Does the scan tool communicate with the PCM?

Go to Step 3

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

3

Select the PCM display DTCs function on the scan tool.

Does the scan tool display any DTCs?

Go to Step 4

Go to Symptoms

4

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

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

Go to Step 5

5

Does the scan tool display DTC P0530 or P1546?

Go to Diagnostic Trouble Code (DTC) List/Type (LG8) or Diagnostic Trouble Code (DTC) List/Type (L36 and L67) in Engine Controls

Go to Symptoms