Engine. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35
DESCRIPTION
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
INSPECTION PROCEDURE
READ DTC OUTPUT
READ VALUE USING OXYGEN SENSOR (OUTPUT VOLTAGE)
CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT)
INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)
PERFORM CONFIRMATION DRIVING PATTERN
CHECK WHETHER DTC OUTPUT RECURS (DTC P0138 or P0158)
READ VALUE USING OXYGEN SENSOR (OUTPUT VOLTAGE)
PERFORM CONFIRMATION DRIVING PATTERN
CHECK WHETHER DTC OUTPUT RECURS (DTC P0136 or P0156)
REPLACE HEATED OXYGEN SENSOR
PERFORM CONFIRMATION DRIVING PATTERN
CHECK WHETHER DTC OUTPUT RECURS (DTC P0136 or P0156)
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME)
CHECK FOR EXHAUST GAS LEAKS
INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)
CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)
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 P0156 Oxygen Sensor Circuit Malfunction (Bank 2 Sensor 2) |
DTC P0157 Oxygen Sensor Circuit Low Voltage (Bank 2 Sensor 2) |
DTC P0158 Oxygen Sensor Circuit High Voltage (Bank 2 Sensor 2) |
DESCRIPTION
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.
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
| - 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 (A/F) sensor (bank 1, 2 sensor 1)
- Gas leakage 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
| - 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)
- Gas leakage 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
| - Short in HO2 sensor (bank 1, 2 sensor 2) circuit
- HO2 sensor (bank 1, 2 sensor 2)
- ECM internal circuit malfunction
|
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.
- 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.
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 (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 2500 rpm for approximately 90 seconds.
- On the tester, enter the following menus: Powertrain / Engine and ECT / 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
| 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 pressure
- Gas leakage from exhaust system
(Air fuel ratio extremely lean or rich)
|
- 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 (RAV4_ACA30 RM000000PDS09FX.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.
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 and ECT / DTC.
Read the DTCs.
- Result:
Display (DTC Output)
| Proceed to
|
P0138 or P0158
| A
|
P0137 or P0157
| B
|
P0136 or P0156
| C
|
| 2.READ VALUE USING OXYGEN SENSOR (OUTPUT VOLTAGE) |
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 and ECT / Data List / O2S B1S2 or O2S B2S2.
Allow the engine to idle.
Read the Heated Oxygen (HO2) sensor output voltage while idling.
- Result:
HO2 Sensor Output Voltage
| Proceed to
|
More than 1.2 V
| A
|
Less than 1.0 V
| B
|
| 3.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:
Tester Connection
| Specified Condition
|
HT1B (B96-48) - OX1B (B96-88)
| 10 kΩ or higher
|
HT2B (B96-47) - OX2B (B96-87)
| 10 kΩ or higher
|
Reconnect the ECM connector.
| 4.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:
Tester Connection
| Specified Condition
|
+B (2) - OX1B (3)
| 10 kΩ or higher
|
+B (2) - E2 (4)
| 10 kΩ or higher
|
- Bank 2:
Tester Connection
| Specified Condition
|
+B (2) - OX2B (3)
| 10 kΩ or higher
|
+B (2) - E2 (4)
| 10 kΩ or higher
|
| OK |
|
|
|
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 5.PERFORM CONFIRMATION DRIVING PATTERN |
| 6.CHECK WHETHER DTC OUTPUT RECURS (DTC P0138 or P0158) |
On the intelligent tester, enter the following menus: Powertrain / Engine / DTC.
Read the DTCs.
- Result:
Display (DTC Output)
| Proceed to
|
P0138 or P0158
| A
|
No output
| B
|
| 7.READ VALUE USING OXYGEN SENSOR (OUTPUT VOLTAGE) |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position and turn the tester on.
Start the engine.
Enter the following menus: Powertrain / Engine and ECT / Data List / O2S B1S2 or O2S B2S2.
After warming up the engine, run the engine at an engine speed of 2500 rpm for 3 minutes.
Read the output voltage of the HO2 sensor when the engine rpm is suddenly increased.
- HINT:
- Quickly accelerate the engine to 4000 rpm 3 times using the accelerator pedal.
- Standard voltage:
- Fluctuates between 0.4 V or less and 0.5 V or more.
| 8.PERFORM CONFIRMATION DRIVING PATTERN |
| 9.CHECK WHETHER DTC OUTPUT RECURS (DTC P0136 or P0156) |
On the intelligent tester, enter the following menus: Powertrain / Engine and ECT / DTC.
Read the DTCs.
- Result:
Display (DTC Output)
| Proceed to
|
P0136 or P0156
| A
|
No output
| B
|
| 10.REPLACE HEATED OXYGEN SENSOR |
Replace the hated oxygen sensor (RAV4_ACA30 RM000001ROO00PX.html).
| 11.PERFORM CONFIRMATION DRIVING PATTERN |
| 12.CHECK WHETHER DTC OUTPUT RECURS (DTC P0136 or P0156) |
On the intelligent tester, enter the following menus: Powertrain / Engine and ECT / DTC.
Read the DTCs.
- Result:
Display (DTC Output)
| Proceed to
|
P0136 or P0156
| A
|
No output
| B
|
| 13.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME) |
Connect the intelligent tester to the DLC3.
Start the engine and 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, while monitoring the output voltage of Air-Fuel Ratio (A/F) and HO2 sensor displayed on the tester.
- HINT:
- Change the fuel injection volume within the range of -12 % and +12 %. The injection volume can be changed in 1 % graduations within the range.
- The A/F sensor is displayed as AFS B1S1 or AFS B2S1, and the HO2 sensor is displayed as O2S B1S2 or O2S B2S2, on the intelligent tester.
- Result:
Tester Display (Sensor)
| Voltage Variation
| Proceed to
|
AFS B1S1 (A/F)
AFS B2S1 (A/F)
| Alternates between more and less than 3.3 V
| OK
|
AFS B1S1 (A/F)
AFS B2S1 (A/F)
| Remains more than 3.3 V
| NG
|
AFS B1S1 (A/F)
AFS B2S1 (A/F)
| Remains less than 3.3 V
| NG
|
- HINT:
- A normal HO2 sensor voltage (O2S B1S2 or O2S B2S2) reacts in accordance with increases and decreases in fuel injection volumes. When the A/F sensor voltage remains either less or more than 3.3 V despite the HO2 sensor indicating a normal reaction, the A/F sensor is malfunctioning.
| 14.CHECK FOR EXHAUST GAS LEAKS |
- OK:
- No gas leakage.
| | REPAIR OR REPLACE EXHAUST GAS LEAKAGE POINT |
|
|
| 15.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:
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:
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
|
Reconnect the HO2 sensor connector.
| 16.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):
- Bank 1:
Terminal Connection
| Specified Condition
|
HT1B (E94-1) - HT1B (B96-48)
| Below 1 Ω
|
OX1B (E94-3) - OX1B (B96-88)
| Below 1 Ω
|
E2 (E94-4) - EX1B (B96-65)
| Below 1 Ω
|
- Bank 2:
Terminal Connection
| Specified Condition
|
HT2B (B95-1) - HT2B (B96-47)
| Below 1 Ω
|
OX2B (B95-3) - OX2B (B96-87)
| Below 1 Ω
|
E2 (B95-4) - EX2B (B96-64)
| Below 1 Ω
|
- Standard resistance (Check for short):
- Bank 1:
Terminal Connection
| Specified Condition
|
HT1B (E94-1) or HT1B (B96-48) - Body ground
| 10 kΩ or higher
|
OX1B (E94-3) or OX1B (B96-88) - Body ground
| 10 kΩ or higher
|
E2 (E94-4) or EX1B (B96-65) - Body ground
| 10 kΩ or higher
|
- Bank 2:
Terminal Connection
| Specified Condition
|
HT2B (B95-1) or HT2B (B96-47) - Body ground
| 10 kΩ or higher
|
OX2B (B95-3) or OX2B (B96-87) - Body ground
| 10 kΩ or higher
|
E2 (B95-4) or EX2B (B96-64) - Body ground
| 10 kΩ or higher
|
Reconnect the HO2 sensor connector.
Reconnect the ECM connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
