Signal Circuit Inspection

■ Linear 

1. Ignition "OFF" and disconnect HO2S (B1S1) connector.
2. Ignition "OFF" and disconnect HO2S (B1S1) connector.
3. Measure resistance between Pin No. 1 (Nernst cell voltage) terminal of HO2S (B1S1) harness connector and Pin No. 1 (Nernst cell voltage) terminal of ECM/PCM.
4. Measure resistance between Pin No. 3 (Common ground) terminal of HO2S (B1S1) harness connector and Pin No. 3 (Common ground) terminal of ECM/PCM.
5. Measure resistance between Pin No. 3 (Common ground) terminal of HO2S (B1S1) harness connector and Pin No. 3 (Common ground) terminal of ECM/PCM.
6. Measure resistance between Pin No. 4 (Compensation resistance) terminal of HO2S (B1S1) harness connector and Pin No. 4 (Compensation resistance) terminal of ECM/PCM.

   Specification:  Below 1Ω

7. Is the measured value within specification?

   YES 

   • Go to "Component Inspection " procedure.

   NO 

   • Repair or replace as necessary and then, go to "Verification of Vehicle Repair " procedure.