Diagnosing Customer Concerns Without Hard DTCs

If a lamp fault code is reported by the customer but is not present when the vehicle comes in for service, follow the Diagnostic Instruction procedures in this article to identify the intermittent DTC.

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

• Follow the DEACTIVATION  or DEPOWERING PROCEDURE  as directed in this article.
• Determine the location of components involved in creating the DTC.
• Carry out a thorough visual inspection of:
  • Components.
  • Connectors.
  • Splices and wiring harnesses.
  • Insulation on conductors.

Refer to the POSSIBLE CAUSES  for the DTC involved, which lists the common concerns that relate to the DTC. Concerns are listed according to priority.