Test Description

WARNING: This page is about a different car, the 2004 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.

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

2: 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.
3: If no DTCs are present, refer to the symptom list of further diagnostics.
4: 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.

Diagnostic System Check - Automatic Transmission Shift Lock Control

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	Turn ON the ignition, with the engine OFF. Attempt to establish communication with the Body Control Module (BCM) and the Powertrain Control Module (PCM). Does the scan tool communicate with the Body Control Module (BCM) and the Powertrain Control Module (PCM)?	Go to Step 3	Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications
3	With a scan tools retrieve all DTC's from the following Modules. Body Control Module (BCM) Powertrain Control Module (PCM) Does the scan tool display any DTCs?	Go to Step 4	Go to Symptoms - Automatic Transmission Shift Lock Control
4	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 5
5	Does the scan tool display DTC B1000 or B1001?	Go to Scan Tool Data List in Body Control System	Go to Step 6
6	Does the scan tool display DTC B1328?	Go to Diagnostic Trouble Code (DTC) List in Engine Electrical	Go to Diagnostic Trouble Code (DTC) List DTC List