GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2002 🢒 Express 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Diagnostic System Check - Cruise Control

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Lack of communication may be due to a partial or total malfunction of the 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 on the serial data circuit. The specified procedure will compile all the available information before tests are perform.

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 the ignition ON, with the engine OFF.
  2. Attempt to establish communication with the Powertrain Control Module (PCM).

Does the scan tool communicate with the PCM?

Go to Step 3

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

3

Attempt to establish communication with the 4WAL 3 Sensor (EBCM).

Does the scan tool communicate with the EBCM?

Go to Step 4

Go to Scan Tool Does Not Communicate with Electronic Brake Control Module in Data Link Communications

4

Select the DTCs function on the scan tool for the following modules:

    • 4WAL 3 Sensor (EBCM
    • Powertrain Control Module (PCM)

Does the scan tool display any DTCs for the modules listed above?

Go to Step 5

Go to Symptoms - Cruise Control

5

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

Go to Scan Tool Does Not Communicate with Class 2 Device and to Scan Tool Does Not Communicate with Electronic Brake Control Module in Data Link Communications

Go to Step 6

6

Does the scan tool display DTC P0562, P0563, P1637, or P1638?

Go to Diagnostic Trouble Code (DTC) List in Engine Electrical

Go to Diagnostic Trouble Code (DTC) List