Diagnostic System Check - Theft Deterrent. Buick GL7 (Export) 2000

For 1990-2009 cars

### Test Description

The numbers 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. The symptoms list in Symptoms will determine the correct diagnostic procedure to use.

3. 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.

4. The presence of DTCs B1009 or B2734 indicates an internal module fault.

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:

• | Powertrain Control Module (PCM)

• | PASS-Key Module

Does the scan tool communicate with both of the listed 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 DTC function on the scan tool for the following modules:

• | Powertrain Control Module (PCM)

• | PASS-Key Module

Does the scan tool display any DTCs?

Go to Step 4

Go to Symptoms - Theft Deterrent

4 | Does the scan tool display any DTCs which begin 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 DTCs B1009 or B2734? | Go to DTC B1009 EEPROM Checksum Error or DTC B2734 Coded Key Controller Memory Failure | Go to Diagnostic Trouble Code (DTC) List/Type