Visual Inspection
IG "OFF"
Disconnect HO2S(B1/S1) connector.
Check that HO2S(B1S1) is contaminated or damaged by foreign materials.
Has a problem been found ?
YES
Go to "Check HO2S(B1/S1) performance" as follows.
NO
Substitute with a known - good HO2S(B1/S1) and check for proper operation.
If the problem is corrected, replace HO2S(B1/S1) and go to "Verification of Vehicle Repair" procedure.
Check HO2S(B1/S1) performance
IG "OFF".
Connect probe to terminal 1 of HO2S(B1/S1) connector and select oscilloscope function with scantool.
Warm up the engine to normal operating temperature.
Measure signal waveform of HO2S(B1/S1) with scantool
Is the measured signal waveform within specification ?
YES
Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage. So, check poor connections and the related circuit between ECM and component thoroughly. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
Substitute with a known - good HO2S(B1/S1) and check for proper operation.
If the problem is corrected, replace HO2S(B1/S1) and go to "Verification of Vehicle Repair" procedure.
