Signal Circuit Inspection

Ignition "OFF" and disconnect HO2S (S1) connector.
Ignition "ON"
Measure voltage between Pin No. 2 (Nearmost Voltage) terminal of HO2S (S1) harness connector and chassis ground.
Measure voltage between Pin No. 1 (Virtual Ground) terminal of HO2S (S1) harness connector and chassis ground.

Measure voltage between Pin No. 3 (Current Pump) terminal of HO2S (S1) harness connector and chassis ground.

Measure voltage between Pin No. 6 (Current Adjust) terminal of HO2S (S1) harness connector and chassis ground.

Specification:

Nearmost Voltage: Approx 2.4V

Virtual Ground Output: Approx 2.6V

Pumping Current: Approx 2.4V

Trim Resistor: Approx 2.4V
Is the measured voltage within specification?
YES
- Go to "COMPONENT INSPECTION " procedure.
NO
- Repair or replace as necessary and then, go to "VERIFICATION OF REPAIR " procedure.