Important: The following steps must be completed before using the symptom tables.
- Perform the 
Diagnostic System Check 
 before using the Symptom Tables in order to verify that
all of the following are true:
 
| •  | The control module(s) can communicate via the serial data link. | 
 
- Review the system operation in order to familiarize yourself with
the system functions.
 
Visual/Physical Inspection
|     •  | 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 
Intermittents  and Poor Connections in Wiring Systems.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order
to diagnose the symptom: