GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2003 🢒 CTS - RHD 🢒 Steering 🢒 Variable Effort Steering 🢒 Diagnostic System Check - Variable Effort Steering

Test Description

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

  1. The lack of communication may be caused by a partial or a total malfunction of the circuit containing the class 2 serial data. The specified procedure will determine the particular condition.

    2.

  2. Tests for other electronic brake control module (EBCM) controlled subsystem malfunctions that may use the same inputs as the variable effort steering (VES) system.

    3.

  3. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will collect all the available information before tests are performed.

    4.

  4. Tests if the malfunction lies specifically in the VES system.

Step

Action

Yes

No

Schematic Reference: Steering Assist Schematics

1

Install a scan tool.

Does the scan tool turn ON?

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 EBCM.

Does the scan tool communicate with the EBCM?

Go to Step 3

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

3

Select the ABS Diagnostic Trouble Codes function on the scan tool.

Does the scan tool display any DRP/ABS/TCS or VSES DTCs?

Go to Diagnostic System Check - ABS in Antilock Brake System

Go to Step 4

4

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

Go to Diagnostic Trouble Code (DTC) List in Data Link Communications

Go to Step 5

5

Does the scan tool display "DTC C0450?"

Go to Diagnostic Trouble Code (DTC) List

System OK