Important: The following steps must be completed before using the symptom tables.
   •  There are no DTCs set.    •  The control modules can communicate via the serial data link. 
| • | Inspect for aftermarket devices which could affect the operation of the Antilock Brake System (ABS). Refer to Checking Aftermarket Accessories. | 
| • | Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom. | 
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer Testing for Intermittent Conditions and Poor Connections.
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom: