2Gr-Fe Engine Control System. Dtc P0136 Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2)

A three-way catalytic converter (TWC) is used in order to convert the carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NOx) into less harmful substances. To allow the TWC to function effectively, it is necessary to keep the air-fuel ratio of the engine near the stoichiometric air-fuel ratio. For the purpose of helping the ECM to deliver accurate air-fuel ratio control, the Heated Oxygen (HO2) sensor is used.
The HO2 sensor is located behind the TWC, and detects the oxygen concentration in the exhaust gas. Since the sensor is integrated with the heater that heats the sensing portion, it is possible to detect the oxygen concentration even when the intake air volume is low (the exhaust gas temperature is low).
When the air-fuel ratio becomes lean, the oxygen concentration in the exhaust gas becomes rich. The HO2 sensor informs the ECM that the post-TWC air-fuel ratio is lean (low voltage, i.e. less than 0.45 V).
Conversely, when the air-fuel ratio is richer than the stoichiometric air-fuel level, the oxygen concentration in the exhaust gas becomes lean. The HO2 sensor informs the ECM that the post-TWC air-fuel ratio is rich (high voltage, i.e. more than 0.45 V). The HO2 sensor has the property of changing its output voltage drastically when the air-fuel ratio is close to the stoichiometric level.
The ECM uses the supplementary information from the HO2 sensor to determine whether the air-fuel ratio after the TWC is rich or lean, and adjusts the fuel injection time accordingly. Thus, if the HO2 sensor is working improperly due to internal malfunctions, the ECM is unable to compensate for deviations in the primary air-fuel ratio control.

Camry. Acv40 Gsv40.2Gr-Fe Engine Control System.Sfi System.
Dtc
P0136 Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2)

DTC No.	DTC Detection Condition	Trouble Area
P0136 P0156	Abnormal voltage output: During active air-fuel ratio control, following conditions (a) and (b) are met for a certain period of time (2 trip detection logic): (a) Heated Oxygen (HO2) sensor voltage does not decrease to less than 0.2 V (b) HO2 sensor voltage does not increase to more than 0.6 V Low impedance: Sensor impedance is less than 5 Ω for more than 30 seconds when ECM presumes sensor to be warmed up and operating normally (2 trip detection logic)	Open or short in HO2 sensor (bank 1, 2 sensor 2) circuit HO2 sensor (bank 1, 2 sensor 2) HO2 sensor heater (bank 1, 2 sensor 2) Air fuel ratio sensor (bank 1, 2 sensor 1) Gas leak from exhaust system
P0137 P0157	Low voltage (open): During active air-fuel ratio control, following conditions (a) and (b) are met for a certain period of time (2 trip detection logic): (a) HO2 sensor voltage output less than 0.21 V (b) Target air-fuel ratio rich High impedance: Sensor impedance is 15 kΩ or more for more than 90 seconds when ECM presumes sensor to be warmed up and operating normally (2 trip detection logic)	Open in HO2 sensor (bank 1, 2 sensor 2) circuit HO2 sensor (bank 1, 2 sensor 2) HO2 sensor heater (bank 1, 2 sensor 2) Air fuel ratio sensor (bank 1, 2 sensor 1) Gas leak from exhaust system
P0138 P0158	High voltage (short): During active air-fuel ratio control, following conditions (a) and (b) are met for a certain period of time (2 trip detection logic): (a) HO2 sensor voltage output 0.59 V or more (b) Target air-fuel ratio lean Extremely high voltage (short): HO2 sensor voltage output exceeds 1.2 V for more than 30 seconds (2 trip detection logic)	Short in HO2 sensor (bank 1, 2 sensor 2) circuit HO2 sensor (bank 1, 2 sensor 2) Air fuel ratio sensor (bank 1, 2 sensor 1) ECM

WIRING DIAGRAM

CONFIRMATION DRIVING PATTERN

HINT:

This confirmation driving pattern is used in steps 5, 8 and 11 of the following diagnostic troubleshooting procedure when using an intelligent tester.
Performing this confirmation driving pattern will activate the Heated Oxygen (HO2) sensor monitor. (The catalyst monitor is performed simultaneously.) This is very useful for verifying the completion of a repair.

NOTICE:

This test will not be completed if the vehicle is driven at an absolutely constant speed conditions such as with cruise control activated.

Connect an intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
Clear the DTCs (where set) (CAMRY_ACV40 RM000000PDK01VX.html).
Start the engine and warm it up (Procedure "A").
Drive the vehicle at between 64 km/h and 113 km/h (40 mph and 70 mph) for at least 10 minutes (Procedure "B").
On the tester, select the following menu items: Powertrain / Engine / DTC / Pending and check if any DTCs (any pending DTCs) are set.

INSPECTION PROCEDURE

HINT:

Intelligent tester only:

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 (A/F) sensor, Heated Oxygen (HO2) 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 an intelligent tester.

Connect the intelligent tester to the DLC3.
Start the engine and turn the tester on.
Warm up the engine at an engine speed of 2,500 rpm for approximately 90 seconds.
On the tester, enter the following menus: Powertrain / Active Test / Control the Injection Volume for A/F Sensor.
Perform the Control the Injection Volume for A/F Sensor operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume).
Monitor the voltage outputs of the A/F and HO2 sensors (AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2) displayed on the tester.

HINT:

The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5 % or increases the injection volume by 25 %.
Each sensor reacts in accordance with increases in the fuel injection volume.

Tester Display (Sensor)	Injection Volume	Status	Voltage
AFS B1S1 or AFS B2S1 (A/F)	+25 %	Rich	Less than 3.0 V
AFS B1S1 or AFS B2S1 (A/F)	-12.5 %	Lean	More than 3.35 V
O2S B1S2 or O2S B2S2 (HO2)	+25 %	Rich	More than 0.55 V
O2S B1S2 or O2S B2S2 (HO2)	-12.5 %	Lean	Less than 0.4 V

NOTICE:

The Air-Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen (HO2) sensor has a maximum delay of approximately 20 seconds.

Case	A/F Sensor (Sensor 1) Output Voltage	HO2 Sensor (Sensor 2) Output Voltage	Main Suspected Trouble Area
1	Injection Volume +25 % -12.5 %	Injection Volume +25 % -12.5 %	-
1	Output Voltage More than 3.35 V Less than 3.0 V	Output Voltage More than 0.55 V Less than 0.4 V	-
2	Injection Volume +25 % -12.5 %	Injection Volume +25 % -12.5 %	A/F sensor A/F sensor heater A/F sensor circuit
2	Output Voltage Almost no reaction	Output Voltage More than 0.55 V Less than 0.4 V	A/F sensor A/F sensor heater A/F sensor circuit
3	Injection Volume +25 % -12.5 %	Injection Volume +25 % -12.5 %	HO2 sensor HO2 sensor heater HO2 sensor circuit
3	Output Voltage More than 3.35 V Less than 3.0 V	Output Voltage Almost no reaction	HO2 sensor HO2 sensor heater HO2 sensor circuit
4	Injection Volume +25 % -12.5 %	Injection Volume +25 % -12.5 %	Fuel pressure Gas leakage from exhaust system (Air-fuel ratio extremely lean or rich)
4	Output Voltage Almost no reaction	Output Voltage Almost no reaction

Following the Control the Injection Volume for A/F Sensor procedure enables technicians to check and graph the voltage outputs of both the A/F and HO2 sensors.
The following A/F Control procedure enables the technician to check and graph the voltage output of both the heated oxygen sensors. To display the graph, select the following menu items on the tester: View / Line graph.

HINT:

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 be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction (CAMRY_ACV40 RM000000PDS01FX.html).
If the OX1B wire from the ECM connector is short-circuited to the +B wire, DTC P0136 will be set.
If the OX2B wire from the ECM connector is short-circuited to the +B wire, DTC P0156 will be set.

1.READ OUTPUT DTC

Connect the intelligent tester to the DLC3.

Turn the ignition switch to the ON position.

Turn the tester on.

Enter the following menus: Powertrain / Engine / DTC.

Read the DTCs.

Result:

Result
Proceed to
P0138 or P0158 is output
A
P0137 or P0157 is output
B
P0136 or P0156 is output
C
P0136, P0137, P0138, P0156, P0157 or P0158 and other DTCs are output
D

Go to step 9

Go to step 7

GO TO DTC CHART

A

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

Connect the intelligent tester to the DLC3.

Turn the ignition switch to the ON position and turn the tester on.

Enter the following menus: Powertrain / Engine / Data List / O2S B1S2 or O2S B2S2.

Allow the engine to idle.

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

Go to step 5

A

3.INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)

Disconnect the heated oxygen sensor connector.

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

Standard resistance:
Bank 1 sensor 2:
Tester Connection
Specified Condition
+B (2) - OX1B (3)
10 kΩ or higher
+B (2) - E2 (4)
10 kΩ or higher
Bank 2 sensor 2:
Tester Connection
Specified Condition
+B (2) - OX2B (3)
10 kΩ or higher
+B (2) - E2 (4)
10 kΩ or higher

REPLACE HEATED OXYGEN SENSOR (CAMRY_ACV40 RM000001OOQ002X.html)

OK

4.CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT)

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.

Standard resistance:
RHD:
Tester Connection
Specified Condition
HT1B (C58-48) - OX1B (C58-88)
10 kΩ or higher
HT2B (C58-47) - OX2B (C58-87)
10 kΩ or higher
LHD:
Tester Connection
Specified Condition
HT1B (C55-48) - OX1B (C55-88)
10 kΩ or higher
HT2B (C55-47) - OX2B (C55-87)
10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE ECM (CAMRY_ACV40 RM0000022NT002X.html)

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 / Active Test / Control the Injection Volume.

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

HINT:

Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine gradations within this range.
The air fuel ratio sensor is displayed as AFS Voltage B1S1 or AFS Voltage B2S1, and the heated oxygen sensor is displayed as O2S B1S2 or O2S B2S2 on the tester.

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
Tester Display (Sensor)
Voltage Variation
Proceed to
AFS Voltage B1S1
AFS Voltage B2S1
Alternates between higher than 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 or O2S B2S2) 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.

Result
Tester Display (Sensor)	Voltage Variation	Proceed to
AFS Voltage B1S1 AFS Voltage B2S1	Alternates between higher than and below 3.3 V	OK
Remains at higher than 3.3 V	NG
Remains at below 3.3 V	NG

Go to step 15

OK

6.INSPECT AIR FUEL RATIO SENSOR

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 mA in this test.

Connect the intelligent tester to the DLC3.

Turn the ignition switch to the ON position.

Turn the tester on.

Clear DTCs.

Drive the vehicle according to the drive 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.

Enter the following menus: Powertrain / Engine / Data List / A/F Control System / AFS Current B1S1 or AFS Current B2S1.

Read the value of the air fuel ratio sensor current while the fuel-cut operation is being performed.
Standard current:
Below 3.0 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.

Go to step 12

Go to step 15

7.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE 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 / Active Test / Control the Injection Volume / All Data / O2S B1S2 or O2S B2S2.

Change the fuel injection volume using the tester, monitoring the voltage output of the 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 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.

Go to step 9

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 / Active Test / Control the Injection Volume.

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

HINT:

Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine gradations within this range.
The air fuel ratio sensor is displayed as AFS Voltage B1S1 or AFS Voltage B2S1, and the heated oxygen sensor is displayed as O2S B1S2 or O2S B2S2 on the tester.

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
Tester Display (Sensor)
Voltage Variation
Proceed to
AFS Voltage B1S1
AFS Voltage B2S1
Alternates between higher than 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 or O2S B2S2) 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.

Go to step 15

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

9.CHECK FOR EXHAUST GAS LEAK

Check for exhaust gas leak.
OK:
No gas leakage.

REPAIR OR REPLACE EXHAUST GAS LEAKAGE POINT

OK

10.INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)

Disconnect the heated oxygen sensor connector.

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

Standard resistance:
Bank 1 sensor 2:
Tester Connection
Condition
Specified Condition
HT1B (1) - +B (2)
20°C (68°F)
11 to 16 Ω
HT1B (1) - E2 (4)
Always
10 kΩ or higher
Bank 2 sensor 2:
Tester Connection
Condition
Specified Condition
HT2B (1) - +B (2)
20°C (68°F)
11 to 16 Ω
HT2B (1) - E2 (4)
Always
10 kΩ or higher

REPLACE HEATED OXYGEN SENSOR (CAMRY_ACV40 RM000001OOQ002X.html)

OK

11.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.

Standard resistance (Check for open):

RHD:

Terminal Connection	Specified Condition
HT1B (C52-1) - HT1B (C58-48)	Below 1 Ω
OX1B (C52-3) - OX1B (C58-88)	Below 1 Ω
E2 (C52-4) - EX1B (C58-65)	Below 1 Ω
HT2B (C51-1) - HT2B (C58-47)	Below 1 Ω
OX2B (C51-3) - OX2B (C58-87)	Below 1 Ω
E2 (C51-4) - EX2B (C58-64)	Below 1 Ω

LHD:

Terminal Connection	Specified Condition
HT1B (C52-1) - HT1B (C55-48)	Below 1 Ω
OX1B (C52-3) - OX1B (C55-88)	Below 1 Ω
E2 (C52-4) - EX1B (C55-65)	Below 1 Ω
HT2B (C51-1) - HT2B (C55-47)	Below 1 Ω
OX2B (C51-3) - OX2B (C55-87)	Below 1 Ω
E2 (C51-4) - EX2B (C55-64)	Below 1 Ω

Standard resistance (Check for short):

RHD:

Terminal Connection	Specified Condition
HT1B (C52-1) or HT1B (C58-48) - Body ground	10 kΩ or higher
OX1B (C52-3) or OX1B (C58-88) - Body ground	10 kΩ or higher
E2 (C52-4) or EX1B (C58-65) - Body ground	10 kΩ or higher
HT2B (C51-1) or HT2B (C58-47) - Body ground	10 kΩ or higher
OX2B (C51-3) or OX2B (C58-87) - Body ground	10 kΩ or higher
E2 (C51-4) or EX2B (C58-64) - Body ground	10 kΩ or higher

LHD:

Terminal Connection	Specified Condition
HT1B (C52-1) or HT1B (C55-48) - Body ground	10 kΩ or higher
OX1B (C52-3) or OX1B (C55-88) - Body ground	10 kΩ or higher
E2 (C52-4) or EX1B (C55-65) - Body ground	10 kΩ or higher
HT2B (C51-1) or HT2B (C55-47) - Body ground	10 kΩ or higher
OX2B (C51-3) or OX2B (C55-87) - Body ground	10 kΩ or higher
E2 (C51-4) or EX2B (C55-64) - Body ground	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR (HEATED OXYGEN SENSOR - ECM)

OK

12.REPLACE HEATED OXYGEN SENSOR

Replace the heated oxygen sensor (CAMRY_ACV40 RM000001OOQ002X.html).

NEXT

13.PERFORM CONFIRMATION DRIVING PATTERN

Perform Confirmation Driving Pattern.

NEXT

14.CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137, P0138, P0156, P0157 OR P0158)

Connect the intelligent tester to the DLC3.

Turn the ignition switch to the ON position.

Turn the tester on.

Enter the following menus: Powertrain / Engine / DTC.

Read the DTCs.

Result:

Result
Proceed to
P0136, P0137, P0138, P0156, P0157 or P0158 is output
A
DTC is not output
B

END

REPLACE AIR FUEL RATIO SENSOR

15.REPLACE AIR FUEL RATIO SENSOR

Replace the air fuel ratio sensor.

NEXT

16.PERFORM CONFIRMATION DRIVING PATTERN

Perform Confirmation Driving Pattern.

NEXT

17.CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0138, P0156 OR P0158)

Connect the intelligent tester to the DLC3.

Turn the ignition switch to the ON position.

Turn the tester on.

Enter the following menus: Powertrain / Engine / DTC.

Read the DTCs.

Result:

Result
Proceed to
P0136, P0138, P0156 or P0158 is output
A
DTC is not output
B

END

REPLACE HEATED OXYGEN SENSOR (CAMRY_ACV40 RM000001OOQ002X.html)

Result	Proceed to
P0138 or P0158 is output	A
P0137 or P0157 is output	B
P0136 or P0156 is output	C
P0136, P0137, P0138, P0156, P0157 or P0158 and other DTCs are output	D

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

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

Tester Connection	Specified Condition
+B (2) - OX2B (3)	10 kΩ or higher
+B (2) - E2 (4)	10 kΩ or higher

Tester Connection	Specified Condition
HT1B (C58-48) - OX1B (C58-88)	10 kΩ or higher
HT2B (C58-47) - OX2B (C58-87)	10 kΩ or higher

Tester Connection	Specified Condition
HT1B (C55-48) - OX1B (C55-88)	10 kΩ or higher
HT2B (C55-47) - OX2B (C55-87)	10 kΩ or higher

Tester Connection	Condition	Specified Condition
HT1B (1) - +B (2)	20°C (68°F)	11 to 16 Ω
HT1B (1) - E2 (4)	Always	10 kΩ or higher

Result	Proceed to
P0136, P0138, P0156 or P0158 is output	A
DTC is not output	B