For 1990-2009 cars

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

1. Perform the Air ABS Diagnostic System Check before using the symptom tables in order to verify that the EBCM has not set any diagnostic faults.
2. Review the system description and operation in order to familiarize yourself with the system functions. Refer to Air ABS Description and Operation .

### Visual/Physical Inspection

• | Inspect for aftermarket devices which could affect the operation of the Air 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.

### 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:

• | Air ABS Indicator Always On

• | Air ABS Indicator Inoperative

• | Trailer ABS Indicator Always On

• | Trailer ABS Indicator Inoperative