Without Hard Diagnostic Trouble Codes (DTCs)

DIAGNOSING CUSTOMER CONCERNS WITHOUT HARD DTCS

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 DTC.

Once the DTC is known, read the Normal Operation section of the pinpoint test for the DTC involved.

- Follow the deactivation procedure.
- Determine the location of components involved in creating that code.
- Carry out a thorough visual inspection of:
- components.
- connectors.
- splices and wiring harnesses.
- pinched wires.
- worn insulation on conductors

Refer to the Possible Causes section of the pinpoint test for the DTC involved, which lists the common concerns that relate to the DTC. Concerns are listed according to priority.