GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2003 🢒 CTS - RHD 🢒 Body and Accessories 🢒 Cruise Control 🢒 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 malfunction in the Keyword or the Class 2 serial data circuit. The specified procedure will determine the particular condition.

    2.

  2. The presence of DTCs which begin with U indicates that some other module is not communicating. The specified procedure will compile all the available information before tests are performed.

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 following modules:
    3. • Engine Control Module (ECM)
    • Electronic Brake Control Module (EBCM)

Does the scan tool communicate with the modules listed above?

Go to Step 3

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

3

Important::  The engine may start during the following step. Turn the engine OFF as soon as you have observed the Crank power mode.

  1. With a scan tool, access the Class 2 Power Mode in the Diagnostic Circuit Check.
  2. Rotate the ignition switch through all positions while observing the System Power Mode parameter.

Does the System Power Mode parameter reading match the ignition switch position for all switch positions?

Go to Step 4

Go to Power Mode Mismatch in Body Control System

4

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

    • ECM
    • EBCM

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 in Data Link Communications

Go to Step 6

6

Does the scan tool display DTC P0560, P0562, P0563, P0615, P0616, P0617, P0625, P0626, P2500 or P2501?

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

Go to Diagnostic Trouble Code (DTC) List