Visual Inspection

This inspection will identify modifications or additions to the vehicle operating system that may affect diagnosis. Inspect the vehicle for:

• Add-on devices such as:
  • Air conditioning.
  • Generator.
  • Engine turbo.
  • Cellular telephone.
  • Cruise control.
  • CB radio.
  • Linear booster.
  • Backup alarm signal.
  • Computer.
• Vehicle modification.

These items, if not installed correctly, will affect the powertrain control module (PCM) or transmission function. Pay particular attention to add-on wiring splices in the PCM harness or transmission wiring harness, abnormal tire size, or axle ratio changes.