Control Circuit Inspection
- Check for open in control harness
- Ignition "OFF".
- Disconnect HO2S and ECM connectors.
- Measure resistance between terminals 4 of the HO2S heater harness connector and 1 of the ECM harness connector.
Specification: Approx 0Ω
- Is resistance within the specification?
YES:
- Go to step 2.
NO:
- Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- Check for short to battery in control circuit.
- Reconnect the ECM connector.
- Ignition "ON" & Engine "OFF".
- Measure voltage between terminal 4 of the HO2S heater harness connector and chassis ground.
Specification: Approx. 0V
- Is voltage within the specification?
YES:
- Go to "COMPONENT INSPECTION " procedure.
NO:
- Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.