HO2S Heater Monitor

OBD System Description - HO2S Heater Monitor

SYSTEM DESCRIPTION / MONITORING PROCEDURE
For both primary and secondary HO2S heaters, the system monitors proper current and loaded voltage.

DTC P0135: O2 Sensor Heater Circuit (Sensor-1).

Wiring Diagram:

Wiring Diagram

DTC Detecting Condition:

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure
1. With ignition switch turned OFF, connect scan tool.
2. Turn ON ignition switch and clear DTC using scan tool.
3. Start engine and warm up to normal operating temperature.
4. Run engine at idle speed for 3 min. or more.
5. Check DTC and pending DTC.

Step 1 - 7:

Step 7 Continued - 8:

DTC Troubleshooting

DTC P0141: O2 Sensor Heater Circuit (Sensor-2).

Wiring Diagram:

Wiring Diagram

DTC Detecting Condition:

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

WARNING:
- When performing a road test, select a place where there is no traffic or possibility of a traffic accident and very careful during testing to avoid occurrence of an accident.
- Road test should be carried out with 2 persons, a driver and tester, on a level road.

1. With ignition switch turned OFF, connect scan tool.
2. Turn ON ignition switch and clear DTC using scan tool.
3. Start engine and warm up to normal operating temperature.
4. Increase vehicle speed to 40 mph, 60 km/h or more.
5. Keep the vehicle speed for 5 min. (Throttle valve opening is kept constant in this step.)
6. Stop vehicle and run engine at idle speed for 1 min.
7. Check DTC and pending DTC.