GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 Regal 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Diagnostic System Check

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 or total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.

  1. The presence of DTCs which begin with "U" indicate some of the modules are not communicating.

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 and PCM control module(s).

Does the scan tool communicate with the control module(s)?

Go to Step 3

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

3

Select the control module display DTCs function on the scan tool.

Does the scan tool display any DTCs?

Go to Step 4

Go to Symptoms

4

Does the scan tool display any DTCs which begin with a "U"?

Go to Diagnostic Trouble Code (DTC) List/Type 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 Step 6

6

Does the scan tool display the PCM DTCs P0530 or P1546?

Go to Diagnostic Trouble Code (DTC) List/Type in Engine Controls - 3.1L engine or Diagnostic Trouble Code (DTC) List/Type in Engine Controls - 3.8L

Go to DTC Table