Component Inspection

Ignition "OFF"
Ignition "ON" & Engine "OFF".
Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode.
Using the scantool, clear DTC.
Select "Diagnostic Trouble Codes (DTCs)" mode again.
Are any DTCs present?
YES
- Substitute with a known-good HECU and check for proper operation.
  If problem is corrected, replace HECU and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Fault is intermittent, caused by poor connection in CAN signal harness and/or HECU's connector. Go to "VERIFICATION OF VEHICLE REPAIR " procedure.