IG "OFF" and disconnect HO2S(S1) connector.
Check that HO2S(S1) is contaminated or damaged by foreign materials.
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 Channel A negative probe to Pin No.4 (Trim Resistor).
Connect Channel B positive probe to Pin No.1 (Nernst Voltage) and Channel B negative probe to Pin No.3 (Virtual Ground).
Fig.1) Approx. 2000rpm(A) & Fuel Cut(B)
A : Approx. 2000rpm
CH.1 - Pumping Current & Virtual Ground: - 0.5 ~ 0.4 V
CH.2 - Nernst Voltage & Trim Resistor: -1.0 ~ -0.0 V
B : Fuel Cut
CH.1 - Pumping Current & Virtual Ground: Approx. 0.89V
CH.2 - Nernst Voltage & Trim Resistor: Approx. 0.64V
Does the HO2S(S1) operate properly? (Check variation)
![]() | ▶ Go to "Verification of Vehicle Repair" procedure. |
![]() | ▶ Carefully re-do this troubleshooting guide steps. ▶ If problem still occurs, replace HO2S(S1) and then go to "System Inspection" procedure. |