GM Service Manual Online
For 1990-2009 cars only

Important: The following steps must be completed before using the symptom tables.

  1. Perform the Diagnostic System Check - Vehicle before using the Symptom Tables in order to verify that all of the following are true:
  2. • There are no DTCs set.
    • The control module can communicate via the serial data link.
    • The electric power steering (EPS) assembly has not been damaged from a collision or air bag deployment.
  3. Review the system operation in order to familiarize yourself with the system functions. Refer to Power Steering System Description and Operation .

Visual/Physical Inspection

    • Inspect for aftermarket devices which could affect the operation of the EPS System. Refer to Checking Aftermarket Accessories .
    • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
    • Inspect the vehicles battery and charging system for the proper voltage levels.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .