Control Circuit Inspection

Check for open in control harness.
1. Ignition "OFF".
2. Disconnect PCM connector
3. Measure resistance between terminals 4 of the HO2S heater harness connector and 9 of the PCM harness connector.
  Specification: Approx 0Ω
4. Is resistance within the specification?
  YES
  - Go to next step as below
  NO
  - Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check for short to ground in control circuit.
1. Measure resistance between terminal 4 of the HO2S heater harness connector and chassis ground.
  Specification: infinite
2. Is resistance within the specification?
  YES
  - Go to next step as below
  NO
  - Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check for short to power in control circuit.
1. Reconnect the PCM connector.
2. Ignition "ON" & Engine "OFF"
3. Measure voltage between terminal 4 of the HO2S heater harness connector and chassis ground
  Specification: Approx 0V
4. Is voltage within the specification?
  YES
  - Go to "COMPONENT INSPECTION " procedure.
  NO
  - Repair open or short to ground in control circuit and go to "VERIFICATION OF VEHICLE REPAIR " procedure