Control Circuit Inspection

Check for Open in Control Harness

1. Ignition "OFF"
2. Disconnect ECM connector
3. Measure resistance between terminals 2 of the HO2S heater harness connector and 40 of the ECM harness connector
   1. Specification: Approx. 0Ω
      Fig 1: Measuring Resistance Between Terminals 2 Of HO2S Heater Harness Connector And 40 Of ECM Harness Connector

      
4. Is resistance within the specification?

   YES

   1. Go to next step as below

   NO

   1. Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

Check for Short to Ground in Control Circuit

1. Measure resistance between terminal 2 of the HO2S heater harness connector and chassis ground
   1. Specification: infinite
      Fig 2: Measuring Resistance Between Terminal 2 Of HO2S Heater Harness Connector And Chassis Ground

      
2. Is resistance within the specification?

   YES

   1. Go to next step as below

   NO

   1. Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

Check for Short to Power in Control Circuit

1. Reconnect the ECM connector.
2. Ignition "ON" & Engine "OFF"
3. Measure voltage between terminal 2 of the HO2S heater harness connector and chassis ground
   1. Specification: Approx 0V
      Fig 3: Measuring Voltage Between Terminal 2 Of HO2S Heater Harness Connector And Chassis Ground

      
4. Is voltage within the specification?

   YES

   1. Go to "COMPONENT INSPECTION " procedure

   NO

   1. Repair open or short to ground in control circuit and go to "VERIFICATION OF VEHICLE REPAIR " procedure