Important Preliminary Inspections Before Starting

Before using this section, perform the Diagnostic System Check - Vehicle and verify all of the following conditions:

• The engine control module (ECM) and the malfunction indicator lamp (MIL) are operating correctly.
• Diagnostic trouble codes (DTCs) are not stored.
• The scan tool data is within the normal operating range. Refer to Scan Tool Data List (Engine Control Module) or Scan Tool Data List (Glow Plug Control Module) .
• Verify the customer concern and locate the correct symptom. Inspect the items indicated under that symptom.
• Several of the symptom procedures ask for a careful visual/physical inspection. This step is extremely important, and can lead to correcting a condition without further inspections and can save valuable time.
• Verify the proper installation of any of the following non-original equipment accessories:
  • Lights
  • Cellular phone
  • Remote starter system
  • Non-factory installed alarm