Dtc P0136 Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2)

DESCRIPTION

MONITOR DESCRIPTION

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

WIRING DIAGRAM

INSPECTION PROCEDURE

READ OUTPUT DTC

READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)

INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)

CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT)

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME)

INSPECT AIR FUEL RATIO SENSOR

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)

CHECK FOR EXHAUST GAS LEAK

INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)

CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)

REPLACE HEATED OXYGEN SENSOR

PERFORM CONFIRMATION DRIVING PATTERN

CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137 OR P0138 IS OUTPUT AGAIN)

REPLACE AIR FUEL RATIO SENSOR

PERFORM CONFIRMATION DRIVING PATTERN

CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137 OR P0138 IS OUTPUT AGAIN)

DESCRIPTION

MONITOR DESCRIPTION

1. Active Air-fuel Ratio Control
   The ECM usually performs air-fuel ratio feedback control so that the air fuel ratio sensor output indicates a near stoichiometric air-fuel ratio. This vehicle includes active air-fuel ratio control in addition to regular air-fuel ratio control. The ECM performs active air-fuel ratio control to detect any deterioration in the Three-way Catalytic Converter (TWC) and heated oxygen sensor malfunctions (refer to the diagram below).
   Active air-fuel ratio control is performed for approximately 15 to 20 seconds while driving with a warm engine. During active air-fuel ratio control, the air-fuel ratio is forcibly regulated to become lean or rich by the ECM. If the ECM detects a malfunction, a DTC is stored.
   

1. Abnormal Voltage Output of Heated Oxygen Sensor (DTC P0136)
   While the ECM is performing active air-fuel ratio control, the air-fuel ratio is forcibly regulated to become rich or lean. If the sensor is not functioning properly, the voltage output variation is small. For example, when the heated oxygen sensor voltage does not decrease to below 0.21 V and does not increase to higher than 0.59 V during active air-fuel ratio control, the ECM determines that the sensor voltage output is abnormal and stores DTC P0136.
   
   
   
   
   

1. Open or Short in Heated Oxygen Sensor Circuit (DTC P0137 or P0138)
   During active air-fuel ratio control, the ECM calculates the Oxygen Storage Capacity (OSC)* of the Three-way Catalytic Converter (TWC) by forcibly regulating the air-fuel ratio to become rich or lean. If the heated oxygen sensor has an open or short, or the voltage output of the sensor decreases significantly, the Oxygen Storage Capacity (OSC) is indicated as having an extraordinarily high value. Even if the ECM attempts to continue regulating the air-fuel ratio to become rich or lean, the heated oxygen sensor output does not change.
   While performing active air-fuel ratio control, when the target air-fuel ratio is rich and the heated oxygen sensor voltage output is 0.21 V or less (lean), the ECM interprets this as an abnormally low sensor output voltage and stores DTC P0137. When the target air-fuel ratio is lean and the voltage output is 0.59 V or more (rich) during active air-fuel ratio control, the ECM determines that the sensor voltage output is abnormally high and stores DTC P0138.
   *: The Three-way Catalytic Converter (TWC) has the capability to store oxygen. The Oxygen Storage Capacity (OSC) and the emissions purification capacity of the Three-way Catalytic Converter (TWC) are mutually related. The ECM determines whether the catalyst has deteriorated based on the calculated Oxygen Storage Capacity (OSC) value (HILUX_TGN26 RM000000TMD0C3X.html).
   
   
   
   
   

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

1. Connect the intelligent tester to the DLC3.
   
2. Turn the ignition switch to ON and turn the intelligent tester on.
   
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).
   
4. Turn the ignition switch off and wait for at least 30 seconds.
   
5. Turn the ignition switch to ON and turn the intelligent tester on [A].
   
6. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher [B].
   
7. With the transmission in 5th gear or higher, drive the vehicle at 90 to 120 km/h (56 to 75 mph) for 10 minutes or more [C].
   

   CAUTION:

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

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

   HINT:

   1. If a pending DTC is output, the system is malfunctioning.
      
   2. If a pending DTC is not output, perform the following procedure.
      
10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    
11. Input the DTC: P0136, P0137 or P0138.
    
12. Check the DTC judgment result.
    
    

    Intelligent 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
    N/A	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 N/A, shift the transmission to 2nd gear, and then perform steps [C] and [D] again.
       

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

Malfunctioning areas can be identified by performing the Control the Injection Volume for A/F Sensor function provided in the Active Test. The Control the Injection Volume for A/F Sensor 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 for A/F Sensor operation using the intelligent tester.

1. Connect the intelligent tester to the DLC3.
   
2. Start the engine and turn the intelligent tester on.
   
3. Warm up the engine and run the engine at an engine speed of 2500 rpm for approximately 90 seconds.
   
4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
   
5. Perform the Active Test operation with the engine idling.
   
6. Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the intelligent tester.
   

HINT:

1. Change the fuel injection volume within the range of -12.5% to +12.5%. The injection volume can be changed in fine gradations.
   
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.
   

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
4			Fuel injector assembly Fuel pressure Gas leak from exhaust system (air-fuel ratio extremely rich or lean)

HINT:

1. Following the Control the Injection Volume for A/F Sensor 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 for A/F Sensor / All Data / AFS Voltage B1S1 and O2S B1S2.
   
3. Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. 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.
   
4. If the OX1B wire from the ECM connector is short-circuited to the +B wire, DTC P0136 will be stored.
   
5. Sensor 1 refers to the sensor closest to the engine assembly.
   
6. Sensor 2 refers to the sensor farthest away from the engine assembly.
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the intelligent tester on.
   

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

5. Read DTCs.
   
   

   Result

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

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the intelligent tester on.
   

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

5. Allow the engine to idle.
   

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

   Result:

   
   

   Heated Oxygen Sensor Output Voltage	Proceed to
   1.0 V or higher	A
   Below 1.0 V	B

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) - 3 (OX1B)	Always	10 kΩ or higher
   2 (+B) - 4 (E2)	Always	10 kΩ or higher

   Text in Illustration

   *a	Component without harness connected (to Heated Oxygen Sensor for Bank 1)

1. Turn the ignition switch off and wait for 5 minutes.
   

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
   C75-2 (HT1B) - C75-25 (OX1B)	Always	10 kΩ or higher

1. Connect the intelligent tester to the DLC3.
   

2. Turn the intelligent tester on.
   

3. Start the engine.
   

4. Warm up the engine.
   

5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
   

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

HINT:

1. Change the fuel injection volume within the range of -12.5% to +12.5%. The injection volume can be changed in fine gradations 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 intelligent tester.
   
3. If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.
   


4. 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.
   
   

   Result

   Intelligent tester Display (Sensor)	Voltage Variation	Proceed to
   AFS Voltage B1S1	Alternates between higher than and below 3.3 V	OK
   	Remains higher than 3.3 V	NG
   	Remains 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 either below or higher than 3.3 V despite the heated oxygen sensor indicating a normal reaction, the air fuel ratio sensor is malfunctioning.

   
   
   
   
   
   

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 be below 3.6 mA in this test.

1. Clear DTCs (HILUX_TGN26 RM000000PDK130X.html).
   

2. Drive the vehicle according to the driving pattern listed below.
   

   1. Warm up the engine.
      

   2. Drive the vehicle at 60 km/h (40 mph) or more for 10 minutes or more.
      

   3. Stop the vehicle.
      

   
   
   

   4. Accelerate the vehicle to 60 km/h (40 mph) or more and decelerate for 5 seconds or more. Perform this 3 times.
      

      
      
      
      

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

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

   Standard current:

   Below 3.6 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.
      

1. Connect the intelligent tester to the DLC3.
   

2. Start the engine.
   

3. Turn the intelligent tester on.
   

4. Warm up the engine.
   

5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / All Data / O2S B1S2.
   

6. Change the fuel injection volume using the intelligent tester and monitor the voltage output of the heated oxygen sensors displayed on the intelligent tester.
   

   HINT:

   1. Change the fuel injection volume within the range of -12.5% to +12.5%. The injection volume can be changed in fine gradations 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 voltage:

   Fluctuates between 0.4 V or less and 0.5 V or higher.
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the intelligent tester on.
   

3. Start the engine.
   

4. Warm up the engine.
   

5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
   

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

HINT:

1. Change the fuel injection volume within the range of -12.5% to +12.5%. The injection volume can be changed in fine gradations 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 intelligent tester.
   
3. If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.
   


4. 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.
   
   

   Result

   Intelligent tester Display (Sensor)	Voltage Variation	Proceed to
   AFS Voltage B1S1	Alternates between higher than and below 3.3 V	OK
   	Remains higher than 3.3 V	NG
   	Remains 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 either below or higher than 3.3 V despite the heated oxygen sensor indicating a normal reaction, the air fuel ratio sensor is malfunctioning.

   
   
   
   
   
   

1. Check for exhaust gas leakage.
   

   OK:

   No gas leakage.
   

1. Inspect the heated oxygen sensor (HILUX_TGN26 RM00000159K00IX.html).
   

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
   C88-1 (HT1B) - C75-2 (HT1B)	Always	Below 1 Ω
   C88-3 (OX1B) - C75-25 (OX1B)	Always	Below 1 Ω
   C88-4 (E2) - C75-28 (E2)	Always	Below 1 Ω
   C88-1 (HT1B) or C75-2 (HT1B) - Body ground	Always	10 kΩ or higher
   C88-3 (OX1B) or C75-25 (OX1B) - Body ground	Always	10 kΩ or higher

1. Replace the heated oxygen sensor (HILUX_TGN26 RM00000159M00IX.html).
   

1. Perform Confirmation Driving Pattern (P0136, P0137 and P0138).
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the intelligent tester on.
   

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

4. Input DTCs: P0136, P0137 and P0138.
   

5. Check that the DTC monitor is NORMAL. If the DTC monitor is INCOMPLETE, perform the driving pattern again but increase the vehicle speed.
   
   

   Result

   Display (DTC Output)	Proceed to
   ABNORMAL (P0136, P0137 or P0138 output)	A
   NORMAL (No DTC output)	B

1. Replace the air fuel ratio sensor (HILUX_TGN26 RM00000142300YX.html).
   

1. Perform Confirmation Driving Pattern (P0136, P0137 and P0138).
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the intelligent tester on.
   

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

4. Input DTCs: P0136, P0137 or P0138.
   

5. Check that the DTC monitor is NORMAL. If the DTC monitor is INCOMPLETE, perform the driving pattern again but increase the vehicle speed.
   
   

   Result

   Display (DTC Output)	Proceed to
   ABNORMAL (P0136, P0137 or P0138 output)	A
   NORMAL (No DTC output)	B