P0139
P0139 HO2S2
Description
The heated oxygen sensor 2, after three way catalyst (manifold), monitors the oxygen level in the exhaust gas.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1 are shifted, the air-fuel ratio is controlled to stoichiometric, by the signal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions.
Under normal conditions the heated oxygen sensor 2 is not used for engine control operation.
DTC Logic
DTC DETECTION LOGIC
The heated oxygen sensor 2 has a much longer switching time between rich and lean than the air fuel ratio (A/F) sensor 1. The oxygen storage capacity of the three way catalyst (manifold) causes the longer switching time. To judge the malfunctions of heated oxygen sensor 2, ECM monitors whether the switching response of the sensor's voltage is faster than specified during the various driving condition such as fuel-cut.
DTC CONFIRMATION PROCEDURE
1.INSPECTION START
Do you have CONSULT-III?
Do you have CONSULT-III?
YES - GO TO 2.
NO - GO TO 5.
2.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
For better results, perform "DTC WORK SUPPORT" at a temperature of 0 to 30 �C (32 to 86 �F).
- GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Activate "INSPECTION MODE 1" ( Inspection Mode 1) to start engine, and warm up engine to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON (READY) and select "DATA MONITOR" mode with CONSULT-III.
6. Drive vehicle at a speed of 80 km/h (50 MPH) or more for at least 3 consecutive minutes.
CAUTION:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
NOTE:
Keep the vehicle speed as steady as possible during the cruising.
7. Stop the vehicle and shift the selector lever to P position.
8. Fully depress the accelerator pedal and keep it until step 11.
9. Make sure that "COOLAN TEMP/S" indicates more than 70�C (158�F).
If not, warm up engine and go to next step when "COOLAN TEMP/S" indication reaches to 70�C (158�F).
10. Select "HO2S2 (B1) P0139" of "HO2S2" in "DTC WORK SUPPORT" mode with CONSULT-III.
11. Touch "START".
NOTE:
It will take at most 10 minutes until "COMPLETED" is displayed.
12. Touch "SELF-DIAG RESULT".
Which is displayed on CONSULT-III?
OK - INSPECTION END
NG - GO TO 4.
CAN NOT BE DIAGNOSED-GO TO 4.
4.PERFORM THE RESULT OF DTC CONFIRMATION PROCEDURE
1. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
2. Perform DTC CONFIRMATION PROCEDURE again.
- GO TO 3.
5.PERFORM COMPONENT FUNCTION CHECK
Perform component function check. SEE Component Function Check.
NOTE:
Use component function check to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
YES - INSPECTION END
NO - Go to SEE Diagnosis Procedure.
Component Function Check
1.PERFORM COMPONENT FUNCTION CHECK
Without CONSULT-III
1. Activate "INSPECTION MODE 1" ( Inspection Mode 1) to start engine, and warm up engine to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition ON (READY) and drive vehicle at a speed of 80 km/h (50 MPH) or more for at least 3 consecutive minutes.
CAUTION:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
NOTE:
Keep the vehicle speed as steady as possible during the cruising.
6. Stop vehicle and shift the selector lever to P position.
7. Check the voltage between ECM harness connector and ground under the following condition.
Is the inspection result normal?
YES - INSPECTION END
NO - Go to SEE Diagnosis Procedure.
Diagnosis Procedure
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E9. Refer to Ground Inspection in Circuit Inspection.
Is the inspection result normal?
YES - GO TO 2.
NO - Repair or replace ground connection.
2.CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE
1. Clear the mixture ratio self-learning value. Description Special Repair Requirement, "MIXTURE RATIO SELF-LEARNING VALUE
CLEAR : Special Repair Requirement".
2. Activate "INSPECTION MODE 1" ( Inspection Mode 1) to start engine, and let engine idle for at least 10 minutes.
Is the 1st trip DTC P0171 or P0172 detected? Is it difficult to start engine?
YES - Perform trouble diagnosis for DTC P0171 or P0172. P0171 or P0172, "DTC Logic".
NO - GO TO 3.
3.CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 harness connector.
3. Disconnect ECM harness connector.
4. Check the continuity between HO2S2 harness connector and ECM harness connector.
5. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES - GO TO 4.
NO - Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between HO2S2 harness connector and ECM harness connector.
2. Check the continuity between HO2S2 harness connector or ECM harness connector and ground.
3. Also check harness for short to power.
Is the inspection result normal?
YES - GO TO 5.
NO - Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK HEATED OXYGEN SENSOR 2
SEE Component Inspection.
Is the inspection result normal?
YES - GO TO 7.
NO - GO TO 6.
6.REPLACE HEATED OXYGEN SENSOR 2
Replace heated oxygen sensor 2. Exploded View.
CAUTION:
- Discard any sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new sensor, clean exhaust system threads using oxygen sensor thread cleaner
[commercial service tool: (J-43897-18 or J-43897-12)] and approved anti-seize lubricant (commercial service tool).
- INSPECTION END
7.CHECK INTERMITTENT INCIDENT
Intermittent Incident.
- INSPECTION END
Component Inspection
1.INSPECTION START
Do you have CONSULT-III?
Do you have CONSULT-III?
YES - GO TO 2.
NO - GO TO 3.
2.CHECK HEATED OXYGEN SENSOR 2-I
With CONSULT-III
1. Activate "INSPECTION MODE 1" ( Inspection Mode 1) to start engine, and warm up engine to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition ON (READY) and select "DATA MONITOR" mode with CONSULT-III.
6. Drive vehicle at a speed of 80 km/h (50 MPH) or more for at least 3 consecutive minutes.
CAUTION:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
NOTE:
Keep the vehicle speed as steady as possible during the cruising.
7. Stop vehicle and shift the selector lever to P position.
8. Select "FUEL INJECTION" in "ACTIVE TEST" mode, and select "HO2S2 (B1)" as the monitor item with
CONSULT-III.
9. Check "HO2S2 (B1)" at idle speed when adjusting "FUEL INJECTION" to �25%.
"HO2S2 (B1)" should be above 0.68V at least once when the "FUEL INJECTION" is +25%.
"HO2S2 (B1)" should be below 0.18V at least once when the "FUEL INJECTION" is -25%.
Is the inspection result normal?
YES - INSPECTION END
NO - GO TO 4.
3.CHECK HEATED OXYGEN SENSOR 2-II
Without CONSULT-III
1. Activate "INSPECTION MODE 1" ( Inspection Mode 1) to start engine, and warm up engine to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition ON (READY) and drive vehicle at a speed of 80 km/h (50 MPH) or more for at least 3 consecutive minutes.
CAUTION:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
NOTE:
Keep the vehicle speed as steady as possible during the cruising.
6. Stop vehicle and shift the selector lever to P position.
7. Check the voltage between ECM harness connector and ground under the following condition.
Is the inspection result normal?
YES - INSPECTION END
NO - GO TO 4.
4.REPLACE HEATED OXYGEN SENSOR 2
Replace heated oxygen sensor 2. Exploded View.
CAUTION:
- Discard any sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new sensor, clean exhaust system threads using oxygen sensor thread cleaner
[commercial service tool: (J-43897-18 or J-43897-12)] and approved anti-seize lubricant (commercial service tool).
- INSPECTION END