GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2002 🢒 GMC C-Series Medium Duty Truck B7 🢒 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 malfunction of the communication circuit or due to a total malfunction of the communication circuit. The specified procedure will determine the particular condition.

    2.

  2. The symptom list in Symptoms will determine the correct diagnostic procedure to use.

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 powertrain control module (PCM) and electronic brake control module (EBCM).

Does the scan tool communicate with the control modules?

Go to Step 3

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

3

Select the PCM display DTC function on the scan tool.

Does the scan tool display any DTCs?

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

Go to Step 4

4

Select the EBCM display DTC function on the scan tool.

Does the scan tool display any DTCs?

Go to Diagnostic Trouble Code (DTC) List in Brakes

Go to Symptoms - Cruise Control