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)

for Preparation Click here

DESCRIPTION

HINT:

Sensor 2 refers to the sensor mounted behind the Three-Way Catalytic Converter (TWC) and located far from the engine assembly.

HINT:

*: DTC P0136 and P0138 are for Euro-OBD only.

MONITOR DESCRIPTION

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

1. Connect the intelligent tester to the DLC3.
   
2. Turn the power switch on (IG) and turn the tester on.
   
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).
   
4. Turn the power switch off and wait for at least 30 seconds.
   
5. Turn the power switch on (IG) and turn the tester on [A].
   
6. Put the engine in inspection mode (maintenance mode) (Click here).
   
7. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher [B].
   
8. Drive the vehicle at 75 to 120 km/h (47 to 75 mph) for 10 minutes or more [C].
   

   CAUTION:

   When performing the confirmation driving pattern, obey all speed limits and traffic laws.

9. Enter the following menus: Powertrain / Engine and ECT / DTC [D].
   
10. Read the pending DTC.
    

    HINT:

    1. If a pending DTC is output, the system is malfunctioning.
       
    2. If a pending DTC is not output, perform the following procedure.
       

11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    
12. Input the DTC: P0136, P0137 or P0138.
    
13. Check the DTC judgment result.
    
    

    Tester Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
    UNKNOWN	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    1. If the judgment result shows NORMAL, the system is normal.
       
    2. If the judgment result shows ABNORMAL, the system has a malfunction.
       
    3. If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [C] and [D] again.
       

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

Malfunctioning areas can be identified by performing the Control the Injection Volume function provided in the Active Test. The Control the Injection Volume function can help to determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.

The following instructions describe how to conduct the Control the Injection Volume operation using the intelligent tester.

1. Connect the intelligent tester to the DLC3.
   
2. Turn the power switch on (IG) and turn the tester on.
   
3. Put the engine in inspection mode (maintenance mode) (Click here).
   
4. Start the engine.
   
5. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
   
6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / All Data / AFS Voltage B1S1 and O2S B1S2.
   
7. Perform the Active Test operation with the engine in an idling.
   
8. Monitor the voltage outputs of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the tester.
   

   HINT:

   1. Change the fuel injection volume within the range of -12.0% to +12.0%. The injection volume can be changed in fine gradations.
      
   2. Each sensor reacts in accordance with increases and decreases in the fuel injection volume.
      
   
   

   Tester Display (Sensor)	Injection Volume	Status	Voltage
   AFS Voltage B1S1 (Air fuel ratio)	+12%	Rich	Less than 3.1 V
   AFS Voltage B1S1 (Air fuel ratio)	-12%	Lean	Higher than 3.4 V
   O2S B1S2 (Heated oxygen)	+12%	Rich	Higher than 0.55 V
   O2S B1S2 (Heated oxygen)	-12%	Lean	Less than 0.4 V

   NOTICE:

   The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.

   
   

   Case	Air Fuel Ratio Sensor (Sensor 1) Output Voltage	Heated Oxygen Sensor (Sensor 2) Output Voltage	Main Suspected Trouble Area
   1			-
   2			Air fuel ratio sensor Air fuel ratio sensor heater Air fuel ratio sensor circuit
   3			Heated oxygen sensor Heated oxygen sensor heater Heated oxygen sensor circuit Exhaust gas leaks
   4			Fuel pressure Exhaust gas leaks (Air fuel ratio extremely lean or rich)

1. Following the Control the Injection Volume procedure enables technicians to check and graph the voltage outputs of both the air fuel ratio and heated oxygen sensors.
   
2. To display the graph, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / All Data / AFS Voltage B1S1 and O2S B1S2.
   

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT:

1. If the OX1B wire from the ECM connector is short-circuited to the +B wire, DTC P0136 will be set.
   
2. Sensor 1 refers to the sensor closest to the engine assembly.
   
3. Sensor 2 refers to the sensor farthest away from the engine assembly.
   
4. Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the tester on.
   

4. Enter the following menus: Powertrain / Engine and ECT / DTC.
   

5. Read the DTCs.
   

   Result 

   Result	Proceed to
   DTC P0138 is output	A
   DTC P0137 is output	B
   DTC P0136 is output	C
   P0136, P0137 or P0138 and other DTCs are output	D

B	Go to step 11
C	Go to step 7
D	GO TO DTC CHART (Click here)

A

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the tester on.
   

4. Put the engine in inspection mode (maintenance mode) (Click here).
   

5. Start the engine.
   

6. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / O2S B1S2.
   

7. Read the heated oxygen sensor output voltage while idling.
   
   

   Result 

   Result	Proceed to
   1.0 V or higher	A
   Below 1.0 V	B

B	Go to step 5

A

1. Disconnect the heated oxygen sensor connector.
   

2. Measure the resistance according to the value(s) in the table below.
   

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   2 (+B) - 4 (E2)	Always	10 kΩ or higher
   2 (+B) - 3 (OX1B)	Always	10 kΩ or higher

   Text in Illustration 

   *a	Component without harness connected (Heated Oxygen Sensor (Sensor 2))

NG	REPLACE HEATED OXYGEN SENSOR (Click here)

OK

1. Turn the power switch off and wait for 5 minutes or more.
   

2. Disconnect the ECM connector.
   

3. Measure the resistance according to the value(s) in the table below.
   
   

   Standard Resistance:

   
   

   Tester Connection	Condition	Specified Condition
   D27-41 (HT1B) - D27-125 (OX1B)	Always	10 kΩ or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK
REPLACE ECM (Click here)

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the tester on.
   

4. Put the engine in inspection mode (maintenance mode) (Click here).
   

5. Start the engine and warm it up.
   

6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / All Data / AFS Voltage B1S1 and O2S B1S2.
   

7. Change the fuel injection volume using the tester and monitor the voltage output of air fuel ratio and heated oxygen sensors displayed on the tester.
   

   HINT:

   1. Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine graduations within this range.
      
   2. The air fuel ratio sensor is displayed as AFS Voltage B1S1, and the heated oxygen sensor is displayed as O2S B1S2 on the tester.
      
   3. The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
      
   4. If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.
      
   
   

   Result 

   Tester Display (Sensor)	Voltage Variation	Proceed to
   AFS Voltage B1S1 (Air fuel ratio)	Alternates between higher and below 3.3 V	OK
   	Remains at higher than 3.3 V	NG
   	Remains at below 3.3 V	NG

   HINT:

   A normal heated oxygen sensor voltage (O2S B1S2) reacts in accordance with increases and decreases in fuel injection volumes. When the air fuel ratio sensor voltage remains at either below or higher than 3.3 V despite the heated oxygen sensor indicating a normal reaction, the air fuel ratio sensor is malfunctioning.

   
   
   
   

NG	Go to step 19

OK

HINT:

This air fuel ratio sensor test is to check the air fuel ratio sensor current during the fuel-cut. When the sensor is normal, the sensor current will indicate below 2.2 mA in this test.

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the tester on.
   

4. Clear the DTCs (Click here).
   

5. Put the engine in inspection mode (maintenance mode) (Click here).
   

6. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or more.
   

7. Drive the vehicle at 75 km/h (47 mph) or more for 10 minutes or more.
   

   CAUTION:

   When performing the confirmation driving pattern, obey all speed limits and traffic laws.

8. Stop the vehicle.
   

9. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / AFS Current B1S1.
   

10. Drive the vehicle at 75 km/h (47 mph) or more and decelerate the vehicle for 5 seconds or more. Perform this 3 times.
    

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

    
    
    
    

11. Read the value of the air fuel ratio sensor current while the fuel-cut operation is being performed.
    

    Standard current:

    Below 2.2 mA
    

    HINT:

    1. To measure the air fuel ratio sensor current precisely, perform the fuel-cut operation as long as possible.
       
    2. If it is difficult to measure the air fuel ratio sensor current, use the snapshot function of the intelligent tester.
       

OK	Go to step 14
NG	Go to step 19

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the tester on.
   

4. Put the engine in inspection mode (maintenance mode) (Click here).
   

5. Start the engine and warm it up.
   

6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / All Data / O2S B1S2.
   

7. Change the fuel injection volume using the tester, monitoring the voltage output of the heated oxygen sensor displayed on the tester.
   

   HINT:

   1. Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine graduations within this range.
      
   2. The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
      

   Standard:

   Fluctuates between 0.4 V or less and 0.55 V or higher.
   

NG	Go to step 11

OK

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the tester on.
   

4. Put the engine in inspection mode (maintenance mode) (Click here).
   

5. Start the engine and warm it up.
   

6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / All Data / AFS Voltage B1S1 and O2S B1S2.
   

7. Change the fuel injection volume using the tester and monitor the voltage output of air fuel ratio and heated oxygen sensors displayed on the tester.
   

   HINT:

   1. Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine graduations within this range.
      
   2. The air fuel ratio sensor is displayed as AFS Voltage B1S1, and the heated oxygen sensor is displayed as O2S B1S2 on the tester.
      
   3. The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
      
   4. If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.
      
   
   

   Result 

   Tester Display (Sensor)	Voltage Variation	Proceed to
   AFS Voltage B1S1 (Air fuel ratio)	Alternates between higher and below 3.3 V	OK
   	Remains at higher than 3.3 V	NG
   	Remains at below 3.3 V	NG

   HINT:

   A normal heated oxygen sensor voltage (O2S B1S2) reacts in accordance with increases and decreases in fuel injection volumes. When the air fuel ratio sensor voltage remains at either below or higher than 3.3 V despite the heated oxygen sensor indicating a normal reaction, the air fuel ratio sensor is malfunctioning.

   
   
   
   

NG	Go to step 19

OK

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the tester on.
   

4. Put the engine in inspection mode (maintenance mode) (Click here).
   

5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or more.
   

   HINT:

   The A/C switch and all accessory switches should be off.

6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / All Data / Throttle Idle Position and MAP.
   

7. Confirm that the Throttle Idle Position is ON and check the engine idling condition and MAP values in the Data List while performing the Active Test.
   

   HINT:

   1. Do not leave the EGR valve open for 10 seconds or more during the Active Test.
      
   2. Be sure to return the EGR valve to step 0 when the Active Test is completed.
      
   3. Do not open the EGR valve 30 steps or more during the Active Test.
      

   OK:

   MAP and idling condition change in response to EGR step position when Throttle Idle Position is ON in Data List.
   

   
   

   Standard:

   
   

   -	EGR Step Position (Active Test)
   	0 Steps	0 to 30 Steps
   Idling condition	Steady idling	Idling changes from steady to rough idling or stalls
   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

   HINT:

   During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

   Result 

   Result	Proceed to
   Outside of standard range	A
   Within standard range	B

B	CHECK EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO AND REPAIR CAUSE (FUEL INJECTOR ASSEMBLY, FUEL PRESSURE, GAS LEAK FROM SYSTEM) (Click here)

A

1. Remove the EGR valve assembly (Click here).
   

2. Check if the EGR valve is stuck open.
   

   OK:

   EGR valve is tightly closed.
   

NG	REPLACE EGR VALVE ASSEMBLY (Click here)

OK
CHECK EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO AND REPAIR CAUSE (FUEL INJECTOR ASSEMBLY, FUEL PRESSURE, GAS LEAK FROM SYSTEM) (Click here)

1. Check for exhaust gas leaks.
   

OK:

No gas leaks.

NG	REPAIR OR REPLACE EXHAUST GAS LEAK POINT

OK

1. Inspect the heated oxygen sensor (Click here).
   

NG	REPLACE HEATED OXYGEN SENSOR (Click here)

OK

1. Disconnect the heated oxygen sensor connector.
   

2. Disconnect the ECM connector.
   

3. Measure the resistance according to the value(s) in the table below.
   
   

   Standard Resistance:

   
   

   Tester Connection	Condition	Specified Condition
   D9-1 (HT1B) - D27-41 (HT1B)	Always	Below 1 Ω
   D9-3 (OX1B) - D27-125 (OX1B)	Always	Below 1 Ω
   D9-4 (E2) - D27-102 (O1B-)	Always	Below 1 Ω
   D9-1 (HT1B) or D27-41 (HT1B) - Body ground	Always	10 kΩ or higher
   D9-3 (OX1B) or D27-125 (OX1B) - Body ground	Always	10 kΩ or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

1. Replace the heated oxygen sensor (Click here).
   

NEXT

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the tester on.
   

4. Clear the DTCs (Click here).
   

5. Turn the power switch off and wait for at least 30 seconds.
   

6. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
   

NEXT

1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
   

2. Input the DTCs: P0136, P0137 or P0138.
   

3. Check the DTC judgment result is NORMAL. If it is INCOMPLETE, perform the drive pattern adding the vehicle speed.
   
   

   Result 

   Result	Proceed to
   ABNORMAL (DTC P0136, P0137 or P0138 is output)	A
   NORMAL (DTC is not output)	B

B	END

A

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the tester on.
   

4. Put the engine in inspection mode (maintenance mode) (Click here).
   

5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
   

   HINT:

   The A/C switch and all accessory switches should be off.

6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / All Data / Throttle Idle Position and MAP.
   

7. Confirm that the Throttle Idle Position is ON and check the engine idling condition and MAP values in the Data List while performing the Active Test.
   

   HINT:

   1. Do not leave the EGR valve open for 10 seconds or more during the Active Test.
      
   2. Be sure to return the EGR valve to step 0 when the Active Test is completed.
      
   3. Do not open the EGR valve 30 steps or more during the Active Test.
      

   OK:

   MAP and idling condition change in response to EGR step position when Throttle Idle Position is ON in Data List.
   

   
   

   Standard:

   
   

   -	EGR Step Position (Active Test)
   	0 Steps	0 to 30 Steps
   Idling condition	Steady idling	Idling changes from steady to rough idling or stalls
   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

   HINT:

   During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

   Result 

   Result	Proceed to
   Outside of standard range	A
   Within standard range	B

B	REPLACE AIR FUEL RATIO SENSOR (Click here)

A

1. Remove the EGR valve assembly (Click here).
   

2. Check if the EGR valve is stuck open.
   

   OK:

   EGR valve is tightly closed.
   

NG	REPLACE EGR VALVE ASSEMBLY (Click here)

OK
REPLACE AIR FUEL RATIO SENSOR (Click here)

1. Replace the air fuel ratio sensor (Click here).
   

NEXT

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the tester on.
   

4. Clear the DTCs (Click here).
   

5. Turn the power switch off and wait for at least 30 seconds.
   

6. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
   

NEXT

1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
   

2. Input the DTCs: P0136 or P0138.
   

3. Check the DTC judgment result is NORMAL. If it is INCOMPLETE, perform the driving pattern again and increase the vehicle speed.
   
   

   Result 

   Result	Proceed to
   ABNORMAL (DTC P0136 or P0138 is output)	A
   NORMAL (DTC is not output)	B

B	END

A

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the tester on.
   

4. Put the engine in inspection mode (maintenance mode) (Click here).
   

5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
   

   HINT:

   The A/C switch and all accessory switches should be off.

6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / All Data / Throttle Idle Position and MAP.
   

7. Confirm that the Throttle Idle Position is ON and check the engine idling condition and MAP values in the Data List while performing the Active Test.
   

   HINT:

   1. Do not leave the EGR valve open for 10 seconds or more during the Active Test.
      
   2. Be sure to return the EGR valve to step 0 when the Active Test is completed.
      
   3. Do not open the EGR valve 30 steps or more during the Active Test.
      

   OK:

   MAP and idling condition change in response to EGR step position when Throttle Idle Position is ON in Data List.
   

   
   

   Standard:

   
   

   -	EGR Step Position (Active Test)
   	0 Steps	0 to 30 Steps
   Idling condition	Steady idling	Idling changes from steady to rough idling or stalls
   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

   HINT:

   During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

   Result 

   Result	Proceed to
   Outside of standard range	A
   Within standard range	B

B	REPLACE HEATED OXYGEN SENSOR (Click here)

A

1. Remove the EGR valve assembly (Click here).
   

2. Check if the EGR valve is stuck open.
   

   OK:

   EGR valve is tightly closed.
   

NG	REPLACE EGR VALVE ASSEMBLY (Click here)

OK
REPLACE HEATED OXYGEN SENSOR (Click here)