Initial Inspection and Diagnostic Overview
Engine Ignition
Inspection and verification
1. Verify the customer concern.
2. Visually inspect for obvious mechanical or electrical faults.
Mechanical Electrical
^ Fuses
^ Wiring harness
^ Engine oil level ^ Loose or corroded electrical connectors
^ Cooling system coolant level ^ Ignition coils
^ Fuel level ^ Sensor(s)
^ Fuel contamination/grade/quality ^ Engine control module (ECM)
^ Transmission control module (TCM)
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
4. Use the approved diagnostic system or a scan tool to retrieve any diagnostic trouble codes (DTCs) before moving onto the symptom chart or DTC index.
^ Make sure that all DTCs are cleared following rectification.
Make sure that all DTCs are cleared following rectification.