Diagnostic System Check - Hydraulic Brakes. Buick GL7 (Export) 2000

For 1990-2009 cars

### Test Description

The numbers below refer to the step numbers 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. 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.

3. The presence of DTCs other than those listed are not related to this system.

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 following modules:

• | Instrument cluster (IPC)

• | Body control module (BCM)

• | Electronic brake control module (EBCM)

Does the scan tool communicate with all control modules?

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:

• | Instrument cluster (IPC)

• | Body control module (BCM)

• | Electronic brake control module (EBCM)

Does the scan tool display any DTCs?

Go to Step 4

Go to Symptoms - Hydraulic Brakes

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? | Go to Diagnostic Trouble Code (DTC) List/Type in Body Control System | Go to Symptoms - Hydraulic Brakes