Test Description

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: The symptom list in Symptoms will determine the correct diagnostic procedure to use.
4: The presence of DTCs which begin with "U" indicate that loss of class 2 communications has occurred.

Diagnostic System Check - Audible Warnings

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 the ignition ON, with the engine OFF. Attempt to establish communication with the following control modules: Audio Amplifier Dash Integration Module (DIM) Instrument Panel Cluster (IPC) Radio Does the scan tool communicate with the control modules listed above?	Go to Step 3	Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications
3	Select the display DTCs function on the scan tool for the following control modules: Audio Amplifier Dash Integration Module (DIM) Instrument Panel Cluster (IPC) Radio Does the scan tool display any DTCs?	Go to Step 4	Go to Symptoms - Instrument Panel, Gages and Console
4	Does the scan tool display any other 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, B1004, B1007, B1009, B1372, B1382, or B1390?	Go to Diagnostic Trouble Code (DTC) List in Body Control Systems	Go to Step 6
6	Does the scan tool display DTC B1327, B1513, or B1514?	Go to Diagnostic Trouble Code (DTC) List in Engine Electrical	Go to Diagnostic Trouble Code (DTC) List