P0159

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

Sensor 2 refers to the sensor mounted behind the Three-Way Catalytic Converter (TWC) and located far from the engine assembly.
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 adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometirc.
The HO2S generates a voltage between 0.1 and 0.9 volts 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 volts. 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 volts.

MONITOR DESCRIPTION

The ECM 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

Voltage:

Switching:

Low voltage:

High voltage:

Voltage during fuel-cut:

TYPICAL ENABLING CONDITIONS

All:

Voltage:

Switching:

Low voltage:

High voltage:

Voltage during fuel-cut:

TYPICAL MALFUNCTION THRESHOLDS

Voltage:

Switching:

Low voltage:

High voltage:

Voltage during fuel-cut:

COMPONENT OPERATING RANGE

MONITOR RESULT

Refer to CHECKING MONITOR STATUS (Mode 6 Data).

WIRING DIAGRAM

CONFIRMATION DRIVING PATTERN

HINT:
- This confirmation driving pattern is used in the "PERFORM CONFIRMATION DRIVING PATTERN" procedure of the following diagnostic troubleshooting procedure.
- 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 the repair.

1 Connect Techstream to the DLC3.
2 Turn the ignition switch to the ON position.
3 Start the engine and warm it up [A].
4 Drive the vehicle at between 38 mph and 75 mph (60 km/h and 120 km/h) for at least 10 minutes [B].
5 Turn the tester ON.
6 Select the following menu items: Powertrain / Engine and ECT / Monitor / All / Readiness.
7 Input DTCs: P0136, P0137, P0138, P0139, P0156, P0157, P0158 and P0159.
Check the DTC MONITOR is NORMAL. If DTC MONITOR is Incomplete, perform the drive pattern adding the vehicle speed and using the second 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 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 Techstream.

1 Connect Techstream to the DLC3.
2 Start the engine.
3 Turn the tester on.
4 Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
5 Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F sensor.
6 Perform the Active Test operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume.)
7 Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS B1 S1 or AFS B2 S1 and O2S B1 S2 or O2S B2 S2) displayed on the tester.

HINT:
- The Control the Injection Volume for air fuel ratio sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
- Each sensor reacts in accordance with increases and decreases in the fuel injection volume.

NOTE: 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.

- 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.
- To display the graph, select the following menu items: 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:
- Read freeze frame data using Techstream. 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.
- If the OX1B or OX2B wire from the ECM connector is short-circuited to the +B wire, DTC P0136 or P0156 may be set.

PROCEDURE

1. READ DTC OUTPUT (DTC P0136, P0137, P0138, P0139, P0156, P0157, P0158 OR P0159)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn the tester on.
(c) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.
(d) Read the DTCs.
Result:

C -- READ VALUE OF TECHSTREAM (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)
B -- CHECK FOR EXHAUST GAS LEAKAGE
A -- Continue to next step.
2. READ VALUE OF TECHSTREAM (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn the tester on.
(c) Select the following menu items: Powertrain / Engine and ECT / Data List / A/F Control System / O2S B1S2 or O2S B2S2.
(d) Allow the engine to idle.
(e) Read the Heated Oxygen (HO2) sensor output voltage while idling.
Result:

B -- INSPECT AIR FUEL RATIO SENSOR
A -- Continue to next step.
3. INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)

(a) Disconnect the heated oxygen sensor connector (Bank 1 Sensor 2) or heated oxygen sensor connector (Bank 2 Sensor 2).
(b) Measure the resistance between the terminals of the HO2 sensor connector.
Standard resistance:
Bank 1
Bank 2

(c) Reconnect the HO2 sensor connector.
NG -- REPLACE HEATED OXYGEN SENSOR
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT)

(a) Turn the ignition switch off and wait for 5 minutes.
(b) Disconnect the ECM connector.
(c) Measure the resistance.
Standard resistance:

(d) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM
5. 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 indicate below 3.0 mA in this test.

(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Drive the vehicle according to the drive pattern listed below:
(1) Warm up the engine until the engine coolant temperature reaches 75°C (167°F) or more.
(2) Drive the vehicle at 60 km/h (40 mph) or more and decelerate the vehicle for 5 seconds or more.
(3) Repeat the deceleration above at least 3 times.

(e) Select the following menu items: Select: Powertrain / Engine and ECT / Monitor / O2 Sensor / Details.
(f) Confirm that RANGE B1S1 is either PASS or FAIL. If the tester shows incomplete, re-check RANGE B1S1 after performing the drive pattern.
(g) Select the RANGE B1S1.
(h) Read the Test Value.
Standard current:
Less than 3.0 mA

HINT: If the tester shows incomplete again, add the vehicle speed and use the second gear to decelerate the vehicle. Refer to the CONFIRMATION DRIVING PATTERN.

NG -- REPLACE AIR FUEL RATIO SENSOR
OK -- REPLACE HEATED OXYGEN SENSOR
6. READ VALUE OF TECHSTREAM (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn the tester on.
(c) Start the engine.
(d) Select the following menu items: Powertrain / Engine and ECT / Data List / O2S B1S2 or O2S B2S2.
(e) After warming up the engine, run the engine at an engine speed of 2,500 rpm for 3 minutes.
(f) Read the output voltage of the HO2 sensor when the engine rpm is suddenly increased.

HINT: Quickly accelerate the engine to 4,000 rpm 3 times using the accelerator pedal.

Standard:
Fluctuates between 0.4 V or less and 0.5 V or more.
NG -- CHECK FOR EXHAUST GAS LEAKAGE
OK -- Continue to next step.
7. PERFORM ACTIVE TEST BY TECHSTREAM (INJECTION VOLUME)
(a) Connect Techstream to the DLC3.
(b) Start the engine and turn the tester on.
(c) Warm up the engine.
(d) Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.
(e) Change the fuel injection volume using the tester, while monitoring the voltage output of Air-Fuel Ratio (A/F) and HO2 sensors 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 REPLACE EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO (INJECTOR, FUEL PRESSURE, GAS LEAKAGE FROM EXHAUST SYSTEM)
8. CHECK FOR EXHAUST GAS LEAKAGE
OK:
No gas leakage.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)

Bank 2

(c) Reconnect the HO2 sensor connector.
NG -- REPLACE HEATED OXYGEN SENSOR
OK -- Continue to next step.
10. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)

(a) Disconnect the heated oxygen sensor connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Bank 1

Bank 2

Standard resistance (Check for short):
Bank 1

Bank 2

(d) Reconnect the heated oxygen sensor connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
11. REPLACE HEATED OXYGEN SENSOR
(a) Replace the heated oxygen sensor.
NEXT -- Continue to next step.
12. PERFORM CONFIRMATION DRIVING PATTERN

HINT: Refer to the CONFIRMATION DRIVING PATTERN.

NEXT -- Continue to next step.
13. CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137, P0138, P0139, P0156, P0157, P0158 or P0159)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Select the following menu item: Powertrain / Engine and ECT / Utility / All Readiness.
(e) Input DTCs: P0136, P0137, P0138, P0139, P0156, P0157, P0158 and P0159.
Check the DTC MONITOR is NORMAL. If DTC MONITOR is Incomplete, perform the drive pattern increasing the vehicle speed and using the second gear to decelerate the vehicle.
Result:

B -- REPLACE AIR FUEL RATIO SENSOR
A -- 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.

NEXT -- Continue to next step.
16. CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137, P0138, P0139, P0156, P0157, P0158 OR P0159)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Select the following menu items: Powertrain / Engine and ECT / Utility / All Readiness.
(e) Input DTCs: P0136, P0137, P0138, P0139, P0156, P0157, P0158 and P0159.
Check the DTC MONITOR is NORMAL. If DTC MONITOR is Incomplete, perform the drive pattern increasing the vehicle speed and using the second gear to decelerate the vehicle.
Result:

B -- REPLACE HEATED OXYGEN SENSOR
A -- END