DTC P0136 Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2) |
DTC P0137 Oxygen Sensor Circuit Low Voltage (Bank 1 Sensor 2) |
DTC P0138 Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 2) |

| DTC No. | DTC Detection Condition | Trouble Area |
| P0136 |
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| P0137 |
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| P0138 |
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| Tester Display | Description |
| NORMAL |
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| ABNORMAL |
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| INCOMPLETE |
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| UNKNOWN |
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| Tester Display (Sensor) | Injection Volume | Status | Voltage |
| AFS Voltage B1S1 (A/F) | +25% | Rich | Less than 3.1 V |
| AFS Voltage B1S1 (A/F) | -12.5% | Lean | More than 3.4 V |
| O2S B1S2 (HO2) | +25% | Rich | More than 0.55 V |
| O2S B1S2 (HO2) | -12.5% | Lean | Less than 0.4 V |
| Case | A/F Sensor (Sensor 1) Output Voltage | HO2 Sensor (Sensor 2) Output Voltage | Main Suspected Trouble Area |
| 1 | ![]() ![]() | ![]() ![]() | - |
| 2 | ![]() ![]() | ![]() ![]() |
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| 3 | ![]() ![]() | ![]() ![]() |
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| 4 | ![]() ![]() | ![]() ![]() |
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| 1.READ OUTPUT DTC |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / DTC.
Read DTCs.
| Result | Proceed to |
| DTC P0138 is output | A |
| DTC P0137 is output | B |
| DTC P0136 is output | C |
| DTC P0136, P0137 or P0138 and other DTCs are output | D |
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| A | |
| 2.READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR) |
Connect an intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / O2S B1S2.
Allow the engine to idle.
Read the heated oxygen sensor output voltage while idling.
| Result | Proceed to |
| 1.0 V or more | A |
| Less than 1.0 V | B |
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| A | |
| 3.INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT) |
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Disconnect the heated oxygen sensor connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| 2 (+B) - 3 (OX1B) | Always | 10 kΩ or higher |
| 2 (+B) - 4 (E2) | Always | 10 kΩ or higher |
| *a | Component without harness connected (Heated Oxygen Sensor) |
Reconnect the heated oxygen sensor connector.
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| OK | |
| 4.CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT) |
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Turn the ignition switch off and wait for 5 minutes.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| B8-63 (HT1B) - B8-80 (OX1B) | Always | 10 kΩ or higher |
| *a | Front view of wire harness connector (to ECM) |
Reconnect the ECM connector.
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| OK | ||
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| 5.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME) |
Connect the intelligent tester to the DLC3.
Start the engine.
Turn the tester on.
Warm up the engine.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.
Change the fuel injection volume using the tester, and monitor the voltage output of the air fuel ratio sensor and heated oxygen sensor displayed on the tester.
| Tester Display (Sensor) | Voltage Variation | Proceed to |
| AFS Voltage B1S1 (Air fuel ratio) | Alternates between more and less than 3.3 V | OK |
| AFS Voltage B1S1 (Air fuel ratio) | Remains at more than 3.3 V | NG |
| AFS Voltage B1S1 (Air fuel ratio) | Remains at less than 3.3 V | NG |

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| OK | |
| 6.INSPECT AIR FUEL RATIO SENSOR |
Connect an intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Clear DTCs (Click here).
Drive the vehicle by the drive pattern as listed below:
Warm up the engine until the engine coolant temperature reaches 75°C (167°F) or more.
Drive the vehicle at 60 km/h (37 mph) or more, and decelerate the vehicle for 5 seconds or more.
Repeat the deceleration above at least 3 times.

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / AFS Current B1S1.
Read the value of the air fuel ratio sensor current while the fuel-cut operation is performed.
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| 7.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME) |
Connect the intelligent tester to the DLC3.
Start the engine.
Turn the tester on.
Warm up the engine.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / All Data / O2S B1S2.
Change the fuel injection volume using the tester, and monitoring the voltage output of heated oxygen sensor displayed on the tester.
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| OK | |
| 8.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME) |
Connect the intelligent tester to the DLC3.
Start the engine.
Turn the tester on.
Warm up the engine.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.
Change the fuel injection volume using the tester, and monitoring the voltage output of air fuel ratio and heated oxygen sensors displayed on the tester.
| Tester Display (Sensor) | Voltage Variation | Proceed to |
| AFS Voltage B1S1 (Air fuel ratio) | Alternates between more and less than 3.3 V | OK |
| AFS Voltage B1S1 (Air fuel ratio) | Remains at more than 3.3 V | NG |
| AFS Voltage B1S1 (Air fuel ratio) | Remains at less than 3.3 V | NG |

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| OK | |
| 9.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION) |
Check the MAP and Engine Speed in Date List at the idling condition while performing Active Test.
| - | EGR Step Position (Active Test) | |
| 0 Steps | 0 to 30 Steps | |
| Idling condition | Steady idling | Idling changes from steady to rough idling |
| MAP (Data List) | MAP value is 20 to 40 kPa (150 to 300 mmHg) (EGR valve is fully closed) | MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed |
| Result | Proceed to |
| NG | A |
| OK | B |
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| A | |
| 10.INSPECT EGR VALVE ASSEMBLY |
Remove the EGR valve assembly (Click here).
Check for contamination between the EGR valve and housing.
Reinstall the EGR valve assembly (Click here).
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| OK | ||
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| 11.CHECK FOR EXHAUST GAS LEAK |
Check for exhaust gas leaks from the exhaust manifold sub-assembly and exhaust pipes.
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| OK | |
| 12.INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE) |
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Disconnect the heated oxygen sensor connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| 1 (HT1B) - 2 (+B) | 20°C (68°F) | 11 to 16 Ω |
| 3 (OX1B) - 4 (E2) | Always | 10 kΩ or higher |
| *a | Component without harness connected (Heated Oxygen Sensor) |
Reconnect the heated oxygen sensor connector.
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| OK | |
| 13.CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM) |
Disconnect the heated oxygen sensor connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| B19-1 (HT1B)*1 - B8-63 (HT1B) | Always | Below 1 Ω |
| B19-3 (OX1B)*1 - B8-80 (OX1B) | Always | Below 1 Ω |
| B19-4 (E2)*1 - B8-79 (O1B-) | Always | Below 1 Ω |
| B20-1 (HT1B)*2 - B8-63 (HT1B) | Always | Below 1 Ω |
| B20-3 (OX1B)*2 - B8-80 (OX1B) | Always | Below 1 Ω |
| B20-4 (E2)*2 - B8-79 (O1B-) | Always | Below 1 Ω |
| Tester Connection | Condition | Specified Condition |
| B19-1 (HT1B)*1 or B8-63 (HT1B) - Body ground | Always | 10 kΩ or higher |
| B19-3 (OX1B)*1 or B8-80 (OX1B) - Body ground | Always | 10 kΩ or higher |
| B19-4 (E2)*1 or B8-79 (O1B-) - Body ground | Always | 10 kΩ or higher |
| B20-1 (HT1B)*2 or B8-63 (HT1B) - Body ground | Always | 10 kΩ or higher |
| B20-3 (OX1B)*2 or B8-80 (OX1B) - Body ground | Always | 10 kΩ or higher |
| B20-4 (E2)*2 or B8-79 (O1B-) - Body ground | Always | 10 kΩ or higher |
Reconnect the heated oxygen sensor connector.
Reconnect the ECM connector.
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| OK | |
| 14.REPLACE HEATED OXYGEN SENSOR |
Replace the heated oxygen sensor (Click here).
| NEXT | |
| 15.CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137 OR P0138) |
Perform the confirmation driving pattern.
| Result | Proceed to |
| NORMAL (No DTC outputs) | A |
| ABNORMAL (P0136, P0137 or P0138 is output) | B |
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| A | ||
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| 16.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION) |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.
Check the MAP and Engine Speed in Date List at the idling condition while performing Active Test.
| - | EGR Step Position (Active Test) | |
| 0 Steps | 0 to 30 Steps | |
| Idling condition | Steady idling | Idling changes from steady to rough idling |
| MAP (Data List) | MAP value is 20 to 40 kPa (150 to 300 mmHg) (EGR valve is fully closed) | MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed |
| Result | Proceed to |
| NG | A |
| OK | B |
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| A | |
| 17.INSPECT EGR VALVE ASSEMBLY |
Remove the EGR valve assembly (Click here).
Check for contamination between the EGR valve and housing.
Reinstall the EGR valve assembly (Click here).
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| OK | ||
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| 18.REPLACE AIR FUEL RATIO SENSOR |
Replace the air fuel ratio sensor (Click here).
| NEXT | |
| 19.CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137 OR P0138) |
Perform the confirmation driving pattern.
| Result | Proceed to |
| NORMAL (No DTC outputs) | A |
| ABNORMAL (P0136, P0137 or P0138 is output) | B |
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| A | ||
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| 20.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION) |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.
Check the MAP and Engine Speed in Date List at the idling condition while performing Active Test.
| - | EGR Step Position (Active Test) | |
| 0 Steps | 0 to 30 Steps | |
| Idling condition | Steady idling | Idling changes from steady to rough idling |
| MAP (Data List) | MAP value is 20 to 40 kPa (150 to 300 mmHg) (EGR valve is fully closed) | MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed |
| Result | Proceed to |
| NG | A |
| OK | B |
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| A | |
| 21.INSPECT EGR VALVE ASSEMBLY |
Remove the EGR valve assembly (Click here).
Check for contamination between the EGR valve and housing.
Reinstall the EGR valve assembly (Click here).
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| OK | ||
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