P0136

Wiring Diagram:

CIRCUIT DESCRIPTION
The oxygen sensor-1 is installed on the exhaust manifold (precatalyst) and the oxygen sensor-2 is installed on the exhaust pipe (post catalyst). Each sensor detect the concentration of oxygen in the exhaust gases.

ECM (PCM) detects the air-fuel ratio of the mixture supplied to the engine by monitoring the signal (output voltage) from sensor-1.The signal (output voltage) from sensor-2 is used to detect malfunction of the three way catalytic converter.

Each oxygen sensor heater promotes activation of the oxygen sensor.

Detecting Condition / Possible Cause:

DTC CONFIRMATION PROCEDURE

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

1. Turn ignition switch OFF.
Clear DTC with ignition switch ON, check vehicle and environmental condition for:
- Indication of fuel level meter in combination meter: 1/4 or more
- Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mm Hg, 75 kPa or more)
- Ambient temp.: -10 °C, 14 °F or higher
- Intake air temp.: 70 °C, 158 °F or lower
- No exhaust gas leakage and loose connection
2. Warm up engine to normal operating temperature.
3. Drive vehicle under usual driving condition for 5 min. and check HO(2)S-2 output voltage and "short term fuel trim" with "Data List" mode on scan tool, and write it down.
4. Stop vehicle (don't turn ignition switch OFF).
5. Increase vehicle speed to higher than 20 mph, 32 kph and then stop vehicle.
6. Repeat above steps 5.4 times.
7. Increase vehicle speed to about 50 mph (80 kph) in 3rd gear or 2 range
8. Release accelerator pedal and with engine brake applied, keep vehicle coasting (fuel cut condition) for 10 sec. or more.
9. Stop vehicle (don't turn ignition switch OFF) and run engine at idle for 2 min.
After this step 9), if "Oxygen Sensor Monitoring TEST COMPLETED" is displayed in "READINESS TESTS" mode and DTC is not displayed in "DTC" mode, confirmation test is completed.
If "TEST NOT COMPLETED" is still being displayed, proceed to next step 10).
10. Drive vehicle under usual driving condition for 10 min. (or vehicle is at a stop and run engine at idle for 10 min. or longer)
11. Stop vehicle (don't turn ignition switch OFF). Confirm test results according to "Test Result Confirmation Flow Table" of DTC P0420.

Step 1 - 4: