Part 2

4GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0136-P0139, P0156-P0159: Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2)
P0159 - Oxygen Sensor Circuit Slow Response (Bank 2 Sensor 2)

PROCEDURE

1. READ DTC OUTPUT (DTC P0136, P0137, P0138, P0139, P0156, P0157, P0158 OR P0159)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Trouble Codes.

(e) Read the DTCs.

Result:





HINT
If any DTCs other than P0136, P0137, P0138, P0139, P0156, P0157, P0158 and P0159 are output, troubleshoot those DTCs first.

B -- CHECK FOR EXHAUST GAS LEAK

C -- PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE INJECTION VOLUME)

D -- CHECK FOR EXHAUST GAS LEAK

E -- GO TO DTC CHART SFI System
A -- Continue to next step.

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

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / All Data / O2S B1S2 or O2S B2S2.

(e) Allow the engine to idle.

(f) Read the heated oxygen sensor output voltage while idling.

Result:





B -- PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE INJECTION VOLUME)
A -- Continue to next step.

3. INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)

(a) Disconnect the J68*1 or J40*2, Q4*3 HO2 sensor connector.





HINT
- *1: Bank 1 Sensor 2
- *2: Bank 2 Sensor 2 (2WD)
- *3: Bank 2 Sensor 2 (AWD)

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

Standard resistance (Bank 1 sensor 2):





Standard resistance (Bank 2 sensor 2):





NG -- REPLACE HEATED OXYGEN SENSOR Removal
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT)

(a) Turn the engine switch off and wait for 5 minutes.

(b) Disconnect the A6 ECM connector.

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

Standard resistance:





(d) Reconnect the ECM connector.

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

OK -- REPLACE ECM Removal

5. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE INJECTION VOLUME)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Turn the Techstream on.

(d) Warm up the engine.

(e) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume / All Data / AFS Voltage B1S1 or AFS Voltage B2S1.

(f) Change the fuel injection volume using the Techstream, and monitoring the voltage output of air fuel ratio and heated oxygen sensors displayed on the Techstream.

HINT
- Change the fuel injection volume within the range of -12% and +12%. The injection volume can be changed in fine graduations within the 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 Techstream.
- 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.
- If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

Result:





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 less or more than 3.3 V despite the heated oxygen sensor indicating a normal reaction, the air fuel ratio sensor is malfunctioning.





NG -- REPLACE AIR FUEL RATIO SENSOR
OK -- Continue to next step.

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 3.6 mA in this test.

(a) Connect Techstream to the DLC3.

(b) Turn the engine switch on (IG) and turn the Techstream on.

(c) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(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 (37 mph) or more for 10 seconds or more.

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

(3) Stop the vehicle.

(4) Accelerate the vehicle to 60 km/h (37 mph) or more and decelerate for 8 seconds or more. Perform this 3 times.

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

(e) Enter the following menus: Powertrain / Engine / Monitor / Current Monitor / O2 Sensor / Details.

(f) Confirm that the item Current Monitor / O2 Sensor / Current indicates Complete. If the Techstream shows Incomplete, re-check RANGE B1S1 and RANGE B2S1 after performing the drive pattern.

(g) Select the RANGE B1S1 and RANGE B2S1.

(h) Read the Test Value.

Standard current:

Less than 3.6 mA

NOTICE:
Do not turn the engine switch off during this step because the test results will be lost.

HINT
If the Techstream shown Incomplete again, increase the vehicle speed and use the second gear to decelerate the vehicle.

OK -- REPLACE HEATED OXYGEN SENSOR

NG -- REPLACE AIR FUEL RATIO SENSOR

7. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE INJECTION VOLUME)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Turn the Techstream on.

(d) Warm up the engine.

(e) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume / All Data / O2S B1S2 or O2S B2S2.

(f) Change the fuel injection volume using the Techstream, monitoring the voltage output of the heated oxygen sensors displayed on the Techstream.

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 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 0.55 V or more.

NG -- CHECK FOR EXHAUST GAS LEAK
OK -- Continue to next step.

8. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE INJECTION VOLUME)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Turn the Techstream on.

(d) Warm up the engine.

(e) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume / All Data / AFS Voltage B1S1 or AFS Voltage B2S1.

(f) Change the fuel injection volume using the Techstream, and monitoring the voltage output of air fuel ratio and heated oxygen sensors displayed on the Techstream.

HINT
- Change the fuel injection volume within the range of -12% and +12%. The injection volume can be changed in fine graduations within the 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 Techstream.
- 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.
- If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

Result:





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 less or more than 3.3 V despite the heated oxygen sensor indicating a normal reaction, the air fuel ratio sensor is malfunctioning.





NG -- REPLACE AIR FUEL RATIO SENSOR

OK -- CHECK ENGINE TO DETERMINE CAUSE OF EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO (FUEL INJECTOR, FUEL SYSTEM, AIR INDUCTION SYSTEM, ETC.) P0171

9. CHECK FOR EXHAUST GAS LEAK

(a) Check for exhaust gas leaks.

OK:

No gas leaks.

NG -- REPAIR OR REPLACE EXHAUST GAS LEAK POINT
OK -- Continue to next step.

10. INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE) P0037

NG -- REPLACE HEATED OXYGEN SENSOR Removal
OK -- Continue to next step.

11. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)

(a) Disconnect the J68*1 and J40*2, Q4*3 HO2 sensor connector.

HINT
- *1: Bank 1 Sensor 2
- *2: Bank 2 Sensor 2 (2WD)
- *3: Bank 2 Sensor 2 (AWD)

(b) Disconnect the A6 ECM connector.

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

Standard resistance (Check for open):





Standard resistance (Check for short):





(d) Reconnect the HO2 sensor connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (HEATED OXYGEN SENSOR - ECM)
OK -- Continue to next step.

12. REPLACE HEATED OXYGEN SENSOR

(a) Replace the heated oxygen sensor Removal.

NEXT -- Continue to next step.

13. PERFORM CONFIRMATION DRIVING PATTERN

(a) Perform the Confirmation Driving Pattern (P0136, P0137, P0138, P0156, P0157 and P0158).

NEXT -- Continue to next step.

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

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(e) Input DTC: P0136, P0137, P0138, P0156, P0157 or P0158.

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

Result:





B -- END

A -- REPLACE AIR FUEL RATIO SENSOR Removal

15. REPLACE AIR FUEL RATIO SENSOR

(a) Replace the air fuel ratio sensor Removal.

NEXT -- Continue to next step.

16. PERFORM CONFIRMATION DRIVING PATTERN

(a) Perform the Confirmation Driving Pattern (P0136, P0137, P0138, P0156, P0157 and P0158).

NEXT -- Continue to next step.

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

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(e) Input DTC: P0136, P0138, P0156 or P0158.

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

Result:





B -- REPLACE HEATED OXYGEN SENSOR Removal

A -- END

18. CHECK FOR EXHAUST GAS LEAK

(a) Check for exhaust gas leaks.

OK:

No gas leaks.

NG -- REPAIR OR REPLACE EXHAUST GAS LEAK POINT
OK -- Continue to next step.

19. INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)

(a) Turn the engine switch off and wait for 5 minutes.

(b) Disconnect the A6 ECM connector.

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

Standard resistance:





(d) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

20. PERFORM CONFIRMATION DRIVING PATTERN

(a) Perform the Confirmation Driving Pattern (P0139 and P0159).

NEXT -- Continue to next step.

21. READ DTC OUTPUT (DTC P0139 OR P0159 IS OUTPUT AGAIN)

(a) Connect Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(e) Input DTC: P0139 or P0159.

(f) Check that the DTC monitor is NORMAL. If the DTC monitor is INCOMPLETE, perform the drive pattern again but increase the vehicle speed.

Result:





B -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems

A -- REPLACE HEATED OXYGEN SENSOR Removal