Inspection And Verification
CAUTION:
Diagnosis by substitution from a donor vehicle is NOT
acceptable. Substitution of control modules does not guarantee confirmation of a fault and may also cause additional faults in the vehicle being checked and/or the donor vehicle.
NOTE:
Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.
- Verify the customer concern.
- Visually inspect for obvious signs of mechanical or electrical damage.VISUAL INSPECTION
Mechanical Electrical - Fuel filler cap and seal
- Fuel filler neck
- DMTL fresh air filter (restriction, etc)
- Fuel tank (leaks, damage, etc)
- Fuel lines and joints, etc
- Carbon canister
- Purge valve
- Diagnostic module fuel tank leak (DMTL) pump module
- Fuses
- Connectors
- Harness
- Purge valve
- Diagnostic module fuel tank leak (DMTL) pump
- If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- If the cause is not visually evident, verify the symptom and refer to the Symptom Chart, alternatively check for Diagnostic Trouble Codes (DTCs) and refer to the DTC Index.
- Where K-Line, Vacutec or other proprietary smoke test equipment is available, it should be utilized to assist with Evaporative Emissions System leak diagnosis.