Control Circuit Inspection

Check for Open in Harness

1. Ignition "OFF".
2. Disconnect HO2S connector and PCM connector.
3. Measure the resistance between terminal "4" of the HO2S harness connector and "A4" of the PCM harness connector.
   1. Specification: Approx. 0Ω
      Fig 1: Measuring Resistance Between Terminal 4 Of HO2S And A4 Of PCM Harness Connector

      
4. Is the resistance within specifications?

   YES

   1. Go to "CHECK FOR SHORT TO GROUND IN HARNESS" as below.

   NO

   1. Check for open in Heater control harness. Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

Check for Short to Ground in Harness

1. Ignition "OFF".
2. Disconnect HO2S connector and PCM connector.
3. Measure resistance between terminal "4" of the HO2S harness connector and chassis ground.
   1. Specification: Approx. infinit Ω
      Fig 2: Measuring Resistance Between Terminal 4 Of HO2S Harness Connector And Chassis Ground

      
4. Is the resistance within specifications?

   YES

   1. Go to "COMPONENT INSPECTION " procedure.

   NO

   1. Check for short to ground in Heater control harness. Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.