System Inspection
- Back-Up Voltage Inspection
- Ignition "OFF"
- Disconnect PCM/ECM connector.
- Ignition "ON"
- Measure voltage between terminal Memory Power of the PCM/ECM harness connector and chassis ground.
Specification: Remain stable at battery voltage
- Are circuits remaining stable at battery voltage?
YES
- Using a GDS, check PCM/ECM software version and upgrade as necessary. If version is the newest one, check PCM/ECM for contamination, deterioration, or damage. Substitute with a known-good PCM/ECM and check for proper operation. If the problem is corrected, replace PCM/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.