FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Diagnosing Customer Concerns w/out Hard Fault Codes

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 Methods procedures to identify the intermittent DTC.

Once the DTC is known, read the Normal Operation information in the Pinpoint Test of 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 information in the applicable Pinpoint Test, which lists the common concerns that relate to a particular code. Concerns are listed according to priority.