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 - ABS 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(s) can communicate via the serial data link.
  3. Review the system operation in order to familiarize yourself with the system functions. Refer to ABS Description and Operation

Visual/Physical Inspection

    • Inspect for aftermarket devices which could affect the operation of the antilock brake system. Refer to Checking Aftermarket Accessories in Wiring Systems.
    • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
    • Inspect the master cylinder reservoir for the proper brake fluid level.

Intermittent

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

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

    •  ABS Indicator Always On
    •  ABS Indicator Inoperative
    •  Low Traction Indicator Always On
    •  Low Traction Indicator Inoperative
    •  Traction Off Indicator Always On
    •  Traction Off Indicator Inoperative