Test Description

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

The number(s) below refer to the step number(s) 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.
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 - Body Rear End

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 instrument panel cluster (IPC). Does the scan tool communicate with the BCM and the IPC?	Go to Step 3	Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications
3	Select the BCM display DTCs function on the scan tool. Does the scan tool display any DTCs?	Go to Step 4	Go to Symptoms - Body Rear End
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 B1009?	Go to Diagnostic Trouble Code (DTC) List in Body Control System	Go to Step 6
6	Does the scan tool display DTC B1327?	Go to Diagnostic Trouble Code (DTC) List in Engine Electrical	Go to Diagnostic Trouble Code (DTC) List