Diagnosing Customer Concerns Without Hard DTCs/LFCs

If a Lamp Fault Code (LFC) is reported by the customer, but is not present when the vehicle comes in for service, follow the Diagnostic Instructions procedure to identify the intermittent Diagnostic Trouble Code (DTC).

Once the DTC is known, read the Normal Operation for the code involved.
^ Follow the deactivation procedure.
^ Determine the location of components involved in creating that code.
^ Perform a thorough visual inspection of:
- connectors.
- splices and wiring harnesses.
- pinched wires.
- worn insulation on conductors.
- opens, shorts or loosely mounted sensors.

Refer to Possible Causes, which lists the common concerns that relate to a particular code. Concerns are listed according to priority.