Heated Oxygen Sensor (HO2S)
Inspection of VoltageNOTE: Perform the following test only when directed.
1. Warm up the engine and run it at idle.
2. Disconnect the HO2S connector.
3. Connect a voltmeter between the HO2S connector terminal A and a ground.
4. Run the engine at 3,000 rpm until the voltmeter indicates 0 - 1.0 V.
5. Verify the voltage when engine speed is suddenly increased and decreased several times.
- If HO2S is okay, but PID value is out of specification, perform the "Circuit Open/Short Inspection."
- If not as specified, replace the HO2S.
6. Reconnect the HO2S connector.
Circuit Open/Short Inspection
Open circuit
- If there is no continuity, the circuit is open. Repair or replace the harness.
- Heated oxygen circuit (HO2S connector terminal A and PCM connector terminal 2C (Front).)
- Ground circuit (HO2S connector terminal B and PCM connector terminal 3F through common connector (Front).)
- Heated oxygen circuit (HO2S connector terminal A and PCM connector terminal 3J (Rear).)
- Ground circuit (HO2S connector terminal B and PCM connector terminal 3F through common connector (Rear).) (Except CALIFORNIA emission regulations applicable model)
- Heated oxygen circuit (HO2S connector terminal A and PCM connector terminal 3J through common connector (Rear).)
Short circuit
- If there is continuity, the circuit is shorted. Repair or replace the harness.
- HO2S connector terminal A and PCM connector terminal 2C to ground (Front).
- HO2S connector terminal A and PCM connector terminal 3J to ground (Rear).