2.
Is sensor contaminated?
 | ▶ Go to next step as below. |
 | ▶ 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.
Is sensor contaminated?
| ▶ Go to next step as below. |
| ▶ Replace HO2S(S1) and then go to "Verification of Vehicle Repair" procedure. |
EURO4 - HO2S [Bank 1/Sensor1] (Binary type)
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) Approx. 2000rpm(Warm Up) - Signal waveforms of front HO2S(the upper) and rear HO2S(the lower)
EURO5 - HO2S [Bank 1/Sensor1] (Linear type)
Warm up the engine to normal operating temperature.
Connect VMI to GDS and select "Oscilloscope".
Connect Channel A positive probe to Pin No.6 (Pumping Current) and chassis ground.
Connect Channel A Negative probe to Pin No.4 (Current Adjust) and chassis ground.
Connect Channel B Negative probe to Pin No.1 (Nernst Voltage) and chassis ground.
Connect Channel B Negative probe to Pin No.3 (Virtual Ground) and chassis ground.
Fig.1) Engine Idle after Warm Up
Does the HO2S(S1) operate properly? (Check variation)
| ▶ Repair as necessary and go to "Verification of vehicle Repair" procedure. |
| ▶ Go to "System Inspection" procedure. |
