P0139
P0139, P0159 HO2S2
Description
The heated oxygen sensor 2, after three way catalyst 1, monitors the oxygen level in the exhaust gas on each bank.
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 1 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 various driving conditions such as fuel cut.
DTC CONFIRMATION PROCEDURE
1. INSPECTION START
Do you have CONSULT?
Do you have CONSULT?
YES- GO TO 2.
NO- GO TO 7.
2. PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure 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
1.Turn ignition switch ON and select "DATA MONITOR" mode with CONSULT.
2.Start engine and warm it up to the normal operating temperature.
3.Turn ignition switch OFF and wait at least 10 seconds.
4.Turn ignition switch ON.
5.Turn ignition switch OFF and wait at least 10 seconds.
6.Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
7.Let engine idle for 1 minute.
8.Make sure that "COOLAN TEMP/S" indicates more than 70�C (158�F).
9.Drive the vehicle in a proper gear at 60 km/h (38MPH) and maintain the speed.
CAUTION:
Always drive vehicle at a safe speed.
10.Release the accelerator pedal fully at least 5 seconds.
CAUTION:
- Enable the engine brake.
- Always drive carefully.
- Never apply brake when releasing the accelerator pedal.
11.Repeat step 9 and 10 at least 8 times.
12.Check the following item of "DATA MONITOR".
Is "CMPLT" displayed on CONSULT screen?
YES- GO TO 6.
NO-1: "CMPLT" is not displayed on DIAG 1-Perform DTC confirmation procedure again.
NO-2: "CMPLT" is not displayed on DIAG 2-GO TO 4.
4. PERFORM DTC WORK SUPPORT
1.Open engine hood.
2.Select "HO2S2 (B1) P0139" or "HO2S2 (B2) P0159" of "HO2S2" in "DTC WORK SUPPORT" mode with
CONSULT.
3.Start engine and follow the instruction of CONSULT display.
NOTE:
It will take at most 10 minutes until "COMPLETED" is displayed.
Is "COMPLETED" displayed on CONSULT screen?
YES- GO TO 6.
NO- GO TO 5.
5. PERFORM DTC CONFIRMATION PROCEDURE AGAIN
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.
6. PERFORM SELF-DIAGNOSIS
With CONSULT
Perform ECM self-diagnosis.
Is DTC "P0139" or "P0159" detected?
YES- Proceed to "Diagnosis Procedure" .
NO- INSPECTION END
7. PERFORM COMPONENT FUNCTION CHECK
Perform component function check. Refer to "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- Proceed to "Diagnosis Procedure" .
Component Function Check
1. PERFORM COMPONENT FUNCTION CHECK-I
Without CONSULT
1.Start engine and warm it up to the normal operating temperature.
2.Turn ignition switch OFF and wait at least 10 seconds.
3.Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4.Let engine idle for 1 minute.
5.Check the voltage between ECM harness connector terminals under the following condition.
Is the inspection result normal?
YES- INSPECTION END
NO- GO TO 2.
2. PERFORM COMPONENT FUNCTION CHECK-II
Check the voltage between ECM harness connector terminals under the following condition.
Is the inspection result normal?
YES- INSPECTION END
NO- GO TO 3.
3. PERFORM COMPONENT FUNCTION CHECK-III
Check the voltage between ECM harness connector terminals under the following condition.
Is the inspection result normal?
YES- INSPECTION END
NO- Go to "Diagnosis Procedure" .
Diagnosis Procedure
1. CHECK GROUND CONNECTION
1.Turn ignition switch OFF.
2.Check ground connection M95. Refer to Ground Inspection in "Circuit Inspection" 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. Refer to "MIXTURE RATIO SELF-LEARNING VALUE CLEAR : Special Repair Requirement" Special Repair Requirement.
2.Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected? Is it difficult to start engine?
YES- Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to "DTC Logic" P0171
or "DTC Logic" P0171.
NO- GO TO 3.
3. CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1.Turn ignition switch OFF.
2.Disconnect heated oxygen sensor 2 (HO2S2) 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, 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 and ground, 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, short to ground or short to power in harness or connectors.
5. CHECK HEATED OXYGEN SENSOR 2
Refer to "Component Inspection" .
Is the inspection result normal?
YES- GO TO 7.
NO- GO TO 6.
6. REPLACE HEATED OXYGEN SENSOR 2
Replace malfunctioning heated oxygen sensor 2. Refer to "Exploded View" Exploded View.
CAUTION:
- Discard any heated oxygen 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 heated oxygen 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
Refer to "Intermittent Incident" Intermittent Incident.
- INSPECTION END
Component Inspection
1. INSPECTION START
Do you have CONSULT?
Do you have CONSULT?
YES- GO TO 2.
NO- GO TO 3.
2. CHECK HEATED OXYGEN SENSOR 2
With CONSULT
1.Turn ignition switch ON and select "DATA MONITOR" mode with CONSULT.
2.Start engine and warm it up to the normal operating temperature.
3.Turn ignition switch OFF and wait at least 10 seconds.
4.Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5.Let engine idle for 1 minute.
6.Select "FUEL INJECTION" in "ACTIVE TEST" mode, and select "HO2S2 (B1)/(B2)" as the monitor item with CONSULT.
7.Check "HO2S2 (B1)/(B2)" at idle speed when adjusting "FUEL INJECTION" to �25%.
"HO2S2 (B1)/(B2)" should be above 0.68 V at least once when the "FUEL INJECTION" is +25%.
"HO2S2 (B1)/(B2)" should be below 0.18 V at least once when the "FUEL INJECTION" is 25%.
Is the inspection result normal?
YES- INSPECTION END
NO- GO TO 6.
3. CHECK HEATED OXYGEN SENSOR 2-I
Without CONSULT
1.Start engine and warm it up to the normal operating temperature.
2.Turn ignition switch OFF and wait at least 10 seconds.
3.Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4.Let engine idle for 1 minute.
5.Check the voltage between ECM harness connector terminals under the following condition.
Is the inspection result normal?
YES- INSPECTION END
NO- GO TO 4.
4. CHECK HEATED OXYGEN SENSOR 2-II
Check the voltage between ECM harness connector terminals under the following condition.
Is the inspection result normal?
YES- INSPECTION END
NO- GO TO 5.
5. CHECK HEATED OXYGEN SENSOR 2-III
Check the voltage between ECM harness connector terminals under the following condition.
Is the inspection result normal?
YES- INSPECTION END
NO- GO TO 6.
6. REPLACE HEATED OXYGEN SENSOR 2
Replace malfunctioning heated oxygen sensor 2. Refer to "Exploded View" Exploded View.
CAUTION:
- Discard any heated oxygen 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 heated oxygen 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