P0138
P0138, P0158 HO2S2
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.
MALFUNCTION A
To judge the malfunctions of heated oxygen sensor 2, ECM monitors whether the voltage is unusually high during various driving conditions such as fuel cut.
MALFUNCTION B
To judge the malfunctions of heated oxygen sensor 2, ECM monitors whether the minimum voltage of sensor is sufficiently low during various driving conditions such as fuel-cut.
DTC CONFIRMATION PROCEDURE
1. 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.
- GO TO 2.
2. PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A
1.Start engine and warm it up 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.Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
6.Let engine idle for 2 minutes.
7.Check 1st trip DTC.
Is 1st trip DTC detected?
YES- Proceed to "Diagnosis Procedure" .
NO-1- With CONSULT: GO TO 3.
NO-2- Without CONSULT: GO TO 5.
3. PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION B
NOTE:
For better results, perform "DTC WORK SUPPORT" at a temperature of 0 to 30�C (32 to 86�F).
1.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.Check 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 70�C (158�F).
9.Open engine hood.
10.Select "HO2S2 (B1) P1146" (for DTC P0138) or "HO2S2 (B2) P1166" (for DTC P0158) of "HO2S2" in
"DTC WORK SUPPORT" mode with CONSULT.
11.Follow the instruction of CONSULT display.
NOTE:
It will take at most 10 minutes until "COMPLETED" is displayed.
12.Touch "SELF-DIAG RESULTS".
Which is displayed on CONSULT screen?
OK- INSPECTION END
NG- Proceed to "Diagnosis Procedure" .
CON NOT BE DIAGNOSED-GO TO 4.
4. PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION B 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.
5. PERFORM COMPONENT FUNCTION CHECK FOR MALFUNCTION B
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.Turn ignition switch ON.
4.Turn ignition switch OFF and wait at least 10 seconds.
5.Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
6.Let engine idle for 1 minute.
7.Check the voltage between ECM harness connector terminals under the following conditions.
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 conditions.
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 conditions.
Is the inspection result normal?
YES- INSPECTION END
NO- Proceed to "Diagnosis Procedure" .
Diagnosis Procedure
1. INSPECTION START
Confirm the detected malfunction (A or B). Refer to "DTC Logic" .
Which malfunction is detected?
A - GO TO 2.
B - GO TO 6.
2. CHECK HO2S2 CONNECTOR FOR WATER
1.Disconnect heated oxygen sensor 2 harness connector.
2.Check that water is not inside connectors.
Is the inspection result normal?
YES- GO TO 3.
NO- Repair or replace harness or connectors.
3. CHECK HO2S2 GROUND CIRCUIT
1.Disconnect heated oxygen sensor 2 harness connector.
2.Disconnect ECM harness connector.
3.Check the continuity between heated oxygen sensor 2 (HO2S2) harness connector and ECM harness connector.
4.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
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
Check heated oxygen sensor 2. Refer to "Component Inspection" .
Is the inspection result normal?
YES- Check intermittent incident. Refer to "Intermittent Incident" Intermittent Incident.
NO- Replace malfunctioning heated oxygen sensor 2. Refer to "Removal and Installation (LH)" Removal And Installation (LH) or "Removal and Installation (RH)" Removal And Installation (RH).
6. CLEAR MIXTURE RATIO SELF-LEARNING VALUE
1.Clear the mixture ratio self-learning value. Refer to "Work Procedure" Work Procedure.
2.Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected? Is it difficult to start engine?
YES- Perform trouble diagnosis for DTC P0172, P0175. Refer to "DTC Logic" P0172.
NO- GO TO 7.
7. CHECK HO2S2 GROUND CIRCUIT
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 8.
NO- Repair open circuit, short to ground or short to power in harness or connectors.
8. CHECK HO2S2 INPUT SIGNAL CIRCUIT
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 9.
NO- Repair open circuit, short to ground or short to power in harness or connectors.
9. CHECK HEATED OXYGEN SENSOR 2
Check heated oxygen sensor 2. Refer to "Component Inspection"
Is the inspection result normal?
YES- Check intermittent incident. Refer to "Intermittent Incident" Intermittent Incident.
NO- Replace malfunctioning heated oxygen sensor 2. Refer to "Removal and Installation (LH)" Removal And Installation (LH) or "Removal and Installation (RH)" Removal And Installation (RH).
Component Inspection
1. INSPECTION START
Will CONSULT be used?
Will CONSULT be used?
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- Replace malfunctioning heated oxygen sensor 2. Refer to "Removal and Installation (LH)" Removal And Installation (LH) or "Removal and Installation (RH)" Removal And Installation (RH).
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 conditions.
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 conditions.
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 conditions.
Is the inspection result normal?
YES- INSPECTION END
NO- Replace malfunctioning heated oxygen sensor 2. Refer to "Removal and Installation (LH)" Removal And Installation (LH) or "Removal and Installation (RH)" Removal And Installation (RH).