For 1990-2009 cars

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

1. Perform Diagnostic System Check - Vehicle before using the symptoms tables in order to verify that all of the following are true:

• | There are no DTCs set.

• | The control modules can communicate via the serial data link.

2. 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 .

• | 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 .

### 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

• | Traction Active Indicator Always On

• | Traction Active Indicator Inoperative

• | Traction Control Indicator Always On

• | Traction Control Indicator Inoperative