GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2000 🢒 Grand Prix 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Diagnostic System Check - Engine Electrical

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 serial data circuit or due to a total malfunction of the serial data circuit. The specified procedure will determine the particular condition.

    2.

  2. The symptom list in Symptoms will determine the correct diagnostic procedure to use.

    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.

Step

Action

Yes

No

1

Did you perform the Battery Check?

Go to Step 2

Go to Battery Inspection/Test

2
  1. Install a scan tool
  2. Turn ON the ignition, with the engine OFF.

Does the scan tool power up?

Go to Step 3

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

3

Attempt to establish communication with the following:

    • Vehicle Theft Deterrent Module (VTD)
    • 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 Data Line in Data Link Communications

4

Select the VTD and PCM display DTC function on the scan tool.

Does the scan tool display any DTCs?

Go to Step 5

Go to Symptoms

5

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

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

Go to Step 6

6

Does the scan tool display any DTCs in the PCM which begin with P?

Go to Diagnostic Trouble Code (DTC) List/Type in Engine Controls - 3.1L (LG8) or Diagnostic Trouble Code (DTC) List/Type in Engine Controls - 3.8L

Go to Step 7

7

Does the scan tool display any DTCs in the VTD which begin with B?

Go to Diagnostic Trouble Code (DTC) List/Type in Theft Deterrent

System OK