P0157
3MZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0136: Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2)
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 P0139 - Oxygen Sensor Circuit Slow Response (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)
DTC P0159 - Oxygen Sensor Circuit Slow Response (Bank 2 Sensor 2)
DESCRIPTION
The heated oxygen sensor (HO2S) is used to monitor oxygen in the exhaust gas. For optimum catalyst operation, the air fuel mixture (air-fuel ratio) must be maintained near the ideal "stoichiometric" ratio. The HO2S output voltage changes suddenly in the vicinity of the stoichiometric ratio. The ECM (Included in HV control ECU) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric.
The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes "Lean". The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes "Rich". The ECM interprets Rich when the HO2S voltage is above 0.45 V.
MONITOR DESCRIPTION
The ECM (Included in HV control ECU) monitors the rear Heated Oxygen (HO2) sensor to check for the following malfunctions. If any of the malfunctions are detected, the ECM illuminates the MIL and sets a DTC.
- The HO2 sensor output voltage remains above 0.45 V (rich) or below 0.45 V (lean) while the vehicle is accelerated and decelerated for 8 minutes.
- The HO2 sensor output voltage remains at below 0.05 V, for a long period of time while the vehicle is driven.
- The HO2 sensor output voltage does not decrease below 0.2 V (extremely lean condition) within 7 seconds after fuel-cut is performed while the vehicle is decelerated. The ECM interprets this as the sensor response having deteriorated.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All:
Heated oxygen sensor output voltage (Output voltage, High voltage, Low voltage):
Heated oxygen sensor impedance (Low):
Heated oxygen sensor impedance (High):
Heated oxygen sensor output voltage (Extremely high):
Heated oxygen sensor voltage during fuel cut:
TYPICAL MALFUNCTION THRESHOLDS
Heated oxygen sensor output voltage (Output voltage):
Heated oxygen sensor output voltage (Low voltage):
Heated oxygen sensor output voltage (High voltage):
Heated oxygen sensor impedance (Low):
Heated oxygen sensor impedance (High):
Heated oxygen sensor output voltage (Extremely high):
Heated oxygen sensor voltage during fuel-cut:
COMPONENT OPERATING RANGE
MONITOR RESULT
Refer to CHECKING MONITOR STATUS Mode 6 Data.
The test value and test limit information are described as shown in the following table. Check the monitor result and test values after performing the monitor drive pattern (refer to "Confirmation Monitor").
- MID (Monitor Identification Date) is assigned to each emission-related component.
- TID (Test Identification Date) is assigned to each test value.
- Scaling is used to calculate the test value indicated on generic OBD II scan tools.
HO2S bank 1 sensor 2
HO2S bank 2 sensor 2
If the sensor voltage is outside the standard values, the ECM (Included in HV control ECU) interprets this as a malfunction and sets a DTC.
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
- (a) Connect Techstream to the DLC3.
- (b) Switch the ECM (Included in HV control ECU) from normal mode to check mode using the tester Check Mode Procedure.
- (c) Start the engine and warm it up until the engine coolant temperature reaches more than 75°C (167°F) or more [A].
- (d) Drive the vehicle at 44 to 75 mph (70 to 120 km/h) for at 10 minutes [B].
- (e) Drive the vehicle according to the driving pattern listed below:
(1) Drive the vehicle at 90 km/h (56 mph) for 5 minutes or more.
(2) Release the accelerator pedal to decelerate the vehicle to 70 km/h (44 mph) for 7 seconds or more.
(3) Repeat the above steps 3 times.
- (f) Select the following menu items: Powertrain / Engine and ECT / Utility / All Readiness.
- (g) Input DTCs: P0136, P0137, P0138, P0139, P0156, P0157, P0158 and P0159.
- (h) Check the DTC MONITOR is NORMAL. If DTC MONITOR is INCOMPLETE, perform the drive pattern adding the vehicle speed and using the second (B) gear to decelerate the vehicle.
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 Techstream.
1 Connect Techstream to the DLC3.
2 Start the engine and turn the tester ON.
3 Warm up the engine at engine speed of 2,500 rpm for approximately 90 seconds.
4 Put the engine in inspection mode Inspection Mode Procedure.
5 On the tester, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
6 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).
7 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.
Standard:
NOTE: The Air-Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen (HO2) sensor has a maximum output delay of approximately 20 seconds.
- 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.
- To display the graph, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / A/F Control System / AFS B1 S1 or AFS B2 S1 and O2S B1 S2 or O2S B2 S2 then press the graph button on the Data List view.
HINT:
- If other DTCs relating to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
- Read freeze frame data using Techstream. The ECM (Included in HV control ECU) 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 running or stopped, 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.
- If the OX1B wire from the ECM (Included in HV control ECU) 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.
PROCEDURE
1. READ OUTPUT DTC
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn the tester ON.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Code.
(d) Read the DTCs.
Result:
C -- READ VALUE USING TECHSTREAM (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)
B -- INSPECT FOR EXHAUST GAS LEAK
A -- Continue to next step.
2. READ VALUE USING TECHSTREAM (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)
(a) Connect Techstream to the DLC3.
(b) Put the engine in inspection mode Inspection Mode Procedure.
(c) Start the engine.
(d) Turn the tester ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / A/F Control System / O2S B1 S2 or O2S B2 S2.
(f) Allow the engine to idle.
(g) Read the Heated Oxygen (HO2) sensor output voltage while idling.
Result:
B -- CHECK AIR FUEL RATIO SENSOR
A -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT)
(a) Disconnect the H29 and H33 HV control ECU connectors.
(b) Measure the resistance between the terminals of the HV control ECU.
Standard resistance:
(c) Reconnect the HV control ECU connector.
NG -- INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)
OK -- REPLACE HV CONTROL ECU
4. INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)
(a) Disconnect the H11 or H20 HO2 sensor connector.
(b) Measure the resistance of the HO2 sensor.
Standard resistance (Bank 1 sensor 2):
Standard resistance (Bank 2 sensor 2):
NG -- REPLACE HEATED OXYGEN SENSOR
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR
5. CHECK AIR FUEL RATIO SENSOR
HINT: This A/F sensor test is to check the A/F sensor current during the fuel-cut. When the sensor is normal, the sensor current will indicate below 3.0 mA in this test.
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn the tester on.
(c) Start the engine and warm it up with all the accessories switched off.
(d) Drive the vehicle according to the drive pattern listed below:
(1) Drive the vehicle at 90 km/h (56 mph) for 5 minutes or more.
(2) Release the accelerator pedal to decelerate the vehicle to 70 km/h (44 mph) for 7 seconds or more.
(3) Repeat the above steps 3 times.
(e) Enter the following menus: Powertrain / Engine and ECT / Monitor / O2 Sensor / Details.
(f) Confirm that RANGE B1 S1 is either PASS or FAIL. If the tester shows incomplete, recheck RANGE B1S1 after performing the drive pattern.
(g) Select RANGE B1 S1.
(h) Read the test value.
Standard:
Less than 3.0 mA
NOTE: Do not turn the ignition switch off, during this step because the test results will be lost.
NG -- REPLACE AIR FUEL RATIO SENSOR
OK -- REPLACE HEATED OXYGEN SENSOR
6. READ VALUE USING TECHSTREAM (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)
(a) Connect Techstream to the DLC3.
(b) Put the engine in inspection mode Inspection Mode Procedure.
(c) Start the engine.
(d) Turn the tester ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / A/F Control System / O2S B1 S2 or O2S B2 S2.
(f) After warming up the engine, run the engine at an engine speed of 2,500 rpm for 3 minutes.
(g) Read the output voltage of the HO2 sensor when the engine rpm is suddenly increased.
Standard voltage:
Fluctuates between 0.4 V or less and 0.5 V or more.
NG -- INSPECT FOR EXHAUST GAS LEAK
OK -- Continue to next step.
7. PERFORM ACTIVE TEST USING TECHSTREAM (INJECTION VOLUME)
(a) Connect Techstream to the DLC3.
(b) Put the engine in inspection mode Inspection Mode Procedure.
(c) Start the engine.
(d) Turn the tester ON.
(e) Warm up the engine.
(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.
(g) Change the fuel injection volume using the tester, 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 Techstream.
Result:
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 at either less or more than 3.3 V despite the HO2 sensor indicating a normal reaction, the A/F sensor is malfunctioning.
NG -- REPLACE AIR FUEL RATIO SENSOR
OK -- CHECK AND REPAIR (INJECTOR, FUEL PRESSURE, GAS LEAKAGE FROM EXHAUST SYSTEM, ETC.)
8. INSPECT FOR EXHAUST GAS LEAK
OK:
No gas leakage.
NG -- REPAIR OR REPLACE EXHAUST GAS LEAKAGE POINT
OK -- Continue to next step.
9. INSPECT HEATED OXYGEN SENSOR
(a) Disconnect the H11 or H20 HO2 sensor connector.
(b) Measure the resistance of the HO2 sensor.
Standard resistance (Bank 1 sensor 2):
Standard resistance (Bank 2 sensor 2):
NG -- REPLACE HEATED OXYGEN SENSOR
OK -- Continue to next step.
10. INSPECT IGCT RELAY
(a) Remove the IGCT relay from the engine room R/B.
(b) Measure the IGCT relay resistance.
Standard resistance:
(c) Reinstall the IGCT relay.
NG -- REPLACE IGCT RELAY
OK -- Continue to next step.
11. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - HV CONTROL ECU)
(a) Disconnect the H11 or H20 HO2 sensor connector.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage between the +B terminal of the HO2 sensor connector and body ground.
Standard voltage:
(d) Turn the ignition switch off.
(e) Disconnect the H29, H32 and H33 HV control ECU connectors.
(f) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Standard resistance (Check for short):
(g) Reconnect the HO2 sensor connector.
(h) Reconnect the HV control ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
12. REPLACE HEATED OXYGEN SENSOR
(a) Replace the heated oxygen sensor.
NEXT -- Continue to next step.
13. PERFORM CONFIRMATION DRIVING PATTERN
HINT: Refer to the CONFIRMATION DRIVING PATTERN
NG -- REPLACE AIR FUEL RATIO SENSOR
OK -- END
14. REPLACE AIR FUEL RATIO SENSOR
(a) Replace the air fuel ratio sensor.
NEXT -- Continue to next step.
15. PERFORM CONFIRMATION DRIVING PATTERN
HINT: Refer to the CONFIRMATION DRIVING PATTERN.
NG -- REPLACE HEATED OXYGEN SENSOR
OK -- END