Check the Signal waveform of HO2S
IG "OFF" and connect HO2S connector.
Engine start.
After warming-up, monitor signal waveform of HO2S with scantool.
Is the sensor switching properly?
YES
Go to "Check HO2S" as below.
NO
Substitute with a known - good HO2S and check for proper operation.
If the problem is corrected, go to "Verification of Vehicle Repair" procedure.
Check HO2S
IG "OFF" and disconnect HO2S connector.
Check that the HO2S is securely installed.
Check the HO2S for contamination or damage
Is the sensor normal?
YES
Substitute with a known - good 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.
There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM. Before or after testing PCM on the vehicle, use this function to reuse the PCM on the others
