System Inspection

Back-Up Voltage Inspection 

1. Ignition "OFF"
2. Disconnect ECM connector
3. Ignition "ON"
4. Measure voltage between terminal 6 of the ECM harness connector and chassis ground

   Specification:  Remain stable at battery voltage

5. Are circuits remaining stable at battery voltage?

   YES 

   • Using a GDS, check ECM software version and upgrade as necessary. If version is the newest one, check ECM for contamination, deterioration, or damage. Substitute with a known-good ECM and check for proper operation. If the problem is corrected, replace ECM and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • If voltage fluctuates, check circuit for loose, bent or corroded terminals, Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.