GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2001 🢒 Regal (China) 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Diagnostic System Check - Lighting Systems

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 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

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 communication with the BCM.

Does the scan tool communicate with the BCM?

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 - Lighting Systems

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, DTC B1007, or DTC B1009?

Go to Diagnostic Trouble Code (DTC) List in Body Control System

Go to Step 6

6

Does the scan tool display DTC B1344?

Go to Diagnostic Trouble Code (DTC) List in Body Control System

Go to Step 7

7

Does the scan tool display DTC C1294 or DTC C1295?

Go to Diagnostic Trouble Code (DTC) List in ABS

Go to Diagnostic Trouble Code (DTC) List