Control Circuit Inspection

■ Check short to ground 

1. IG "OFF". Disconnect HO2S (B1/S2) connector.
2. Measure resistance between control terminal of HO2S (B1/S2) heater harness connector and chassis ground.

   Specification:  Infinite

3. Is the measured resistance within specification?

   YES 

   • Go to "Check open in harness" procedure below.

   NO 

   • Repair short to ground in HO2S (B1/S2) heater control circuit. Go to "VERIFICATION OF VEHICLE REPAIR " procedure.

■ Check open in harness 

1. IG "OFF". Disconnect HO2S (B1/S2) and PCM connector.
2. Measure resistance between control terminal of HO2S (B1/S2) heater harness connector and heater control terminal of PCM harness connector.

   Specification:  Approx. below 1Ω

3. Is the measured resistance within specification?

   YES 

   • Go to "COMPONENT INSPECTION " procedure.

   NO 

   • Repair open in HO2S (B1/S2) heater control circuit. Go to "VERIFICATION OF VEHICLE REPAIR " procedure.