Component Inspection

■ Check HO2S (B1/S1) Heater resistance 

1. IG "OFF". Disconnect HO2S (B1/S1) connector.
2. Measure resistance between power and control terminals of HO2S (B1/S1) heater (Component Side)

   Specification:  2.4 ~ 4.0Ω [20°C (68°F)]

3. Is the measured resistance within specification?

   YES 

   • Substitute with a known - good ECM (PCM) and check for proper operation. If the problem is corrected, go to "Verification of Vehicle Repair " procedure.

   NO 

   • Substitute with a known - good HO2S and check for proper operation. If the problem is corrected, go to "Verification of Vehicle Repair " procedure.