2.
Is sensor contaminated?
 | ▶ Go to "Check HO2S(S1) performance" procedure. |
 | ▶ Replace HO2S(S1) and then go to "Verification of Vehicle Repair" procedure. |
Inspect the front HO2S for any silicon contamination. This contamination will be indicated by a white powdery coating and this will result in a bad false voltage signal.
If contamination is evident on the HO2S, replace contaminated sensor with the new one and go to next step.
Is sensor contaminated?
| ▶ Go to "Check HO2S(S1) performance" procedure. |
| ▶ Replace HO2S(S1) and then go to "Verification of Vehicle Repair" procedure. |
Warm up the engine to normal operating temperature.
Connect VMI to GDS and select "Oscilloscope".
Connect Channel A positive probe to Pin No.1 (Signal) and Channel A negative probe to Pin No.2 (Gorund).
Specification : Signal is switching from rich(above 0.45V) to lean(below 0.45V) a minimum of 3 times in 10 seconds
Fig.1) Engine Idle - Signal waveforms of front HO2S(the upper) and rear HO2S(the lower)
Fig.2) Approx. 2000rpm(Warm Up) - Signal waveforms of front HO2S(the upper) and rear HO2S(the lower)
Does the HO2S(S1) operate properly? (Check variation)
| ▶ Go to "Verification of Vehicle Repair" procedure. |
| ▶ Carefully re-do this troubleshooting guide steps. ▶ If no problems were found with the circuits or connectors, replace the HO2S(S1) and go to "Verification of Vehicle Repair" procedure. |
