Important: The following steps must be completed before using the symptoms tables.
- Perform the
Diagnostic System Check - Lighting Systems
before using the symptom tables in order to verify that all of
the following are true:
• | The control modules can communicate via the serial data link. |
- Review the system operation in order to familiarize yourself with the
system functions. Refer to the following:
Visual/Physical Inspection
Several of the symptom procedures ask for a careful visual/physical check.
This step is extremely important-it could lead to correcting a problem without
further checks and can save valuable time. These checks include the following:
• | Inspect the easily accessible or visible system components and harness
connectors for obvious damage or conditions which could cause the symptom. |
• | If only one lamp is inoperative, inspect and repair a poor connection
or an open in the power feed or ground circuit before replacing the light bulb.
Refer to
Circuit Testing
and
Wiring Repairs
in Wiring Systems. |
Intermittent
Faulty electrical connections or wiring may also 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 a symptom that does not set a DTC: