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Home >> Lexus >> 2011 >> GS 460 V8-4.6L (1UR-FSE) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P2A03

P2A03





1UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2A00, P2A03: A/F Sensor Circuit Slow Response (Bank 1 Sensor 1)
P2A03 - A/F Sensor Circuit Slow Response (Bank 2 Sensor 1)

DESCRIPTION

Refer to DTC P2195 P2195.

HINT
- DTC P2A00 indicates malfunctions related to the bank 1 A/F sensor.
- DTC P2A03 indicates malfunctions related to the bank 2 A/F sensor.
- Bank 1 refers to the bank that includes No. 1 cylinder.
- Bank 2 refers to the bank that includes No. 2 cylinder.
- Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and located near the engine assembly.





MONITOR DESCRIPTION

After engine is warmed up, the ECM performs air-fuel ratio feedback control to maintain the air-fuel ratio at the stoichiometric level. In addition, active A/F control is performed for approximately 10 seconds after preconditions are met in order to measure the A/F sensor response rate. During active A/F control, the ECM forcibly increases and decreases the injection volume a certain amount, based on the stoichiometric air-fuel ratio learned during normal air-fuel ratio control, and measures the A/F sensor response rate. The ECM receives a signal from the A/F sensor while performing active A/F control and uses it to calculate the A/F sensor response rate deterioration level.

If the value for A/F sensor response rate deterioration level is less than the threshold, the ECM interprets this as a malfunction and sets the DTC.





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





MONITOR RESULT

Refer to CHECKING MONITOR STATUS Mode 6 Data.

CONFIRMATION DRIVING PATTERN

HINT
Performing this confirmation driving pattern will activate the air fuel ratio sensor response monitor.





1. Connect the Techstream to the DLC3.

2. Turn the engine switch on (IG).

3. Turn the Techstream on.

4. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

5. Turn the engine switch off and wait for at least 30 seconds.

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

7. Enter the following menus: Powertrain / Engine / Monitor / Current Monitor / O2 Sensor / Details.

8. Check that RES RATE B1S1 and RES RATE B2S1 are Incomplete.

9. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher [A].

10. Drive the vehicle at approximately 60 km/h (38 mph) for 10 minutes or more in a city area.[B]

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

11. Check the monitor result values on the Techstream by entering the following menus: Powertrain / Engine / Monitor / Current Monitor / O2 Sensor / Details / RES RATE B1S1 and B2S1.

12. If the values indicated on the Techstream do not change, perform Readiness Monitor Drive Pattern for the air fuel ratio sensor and heated oxygen sensor Reading and Clearing Diagnostic Trouble Codes.

13. Note the value of Monitor Result.

14. Enter the following menus: Powertrain / Engine / Trouble Codes [E].

15. Read the pending DTCs.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

16. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

17. Input the DTC: P2A00 or P2A03.

18. Check the DTC judgment result.





HINT
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or UNKNOWN, perform the following procedure.

19. Drive the vehicle at a speed between 75 and 100 km/h (47 and 63 mph) for 10 minutes [D].

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

20. Enter the following menus: Powertrain / Engine / Trouble Codes [C].

21. Read the pending DTCs.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

22. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

23. Input the DTC: P2A00 or P2A03.

24. Check the DTC judgment result.





HINT
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.

25. If the judgment result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P2195 P2195.

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 the Techstream.

(a) Connect the Techstream to the DLC3.
(b) Start the engine and turn the Techstream on.
(c) Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
(d) On the Techstream, enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor.
(e) Perform the Active Test operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume).
(f) Monitor the output voltages of the A/F and HO2 sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the Techstream.

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 and decreases in the fuel injection volume.





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 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 / Active Test / Control the Injection Volume for A/F Sensor / Data List / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2.

HINT
- DTC P2A00 or P2A03 may be also set, when the air-fuel ratio is stuck rich or lean.
- A low A/F sensor voltage could be caused by a rich air-fuel mixture. Check for conditions that would cause the engine to run rich.
- A high A/F sensor voltage could be caused by a lean air-fuel mixture. Check for conditions that would cause the engine to run lean.
- Read freeze frame data using the Techstream. 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.
- Bank 1 refers to the bank that includes the No. 1 cylinder*.
*: The No. 1 cylinder is the cylinder which is farthest from the transmission.
- Bank 2 refers to the bank that does not include the No. 1 cylinder.
- Sensor 1 refers to the sensor closest to the engine assembly.
- Sensor 2 refers to the sensor farthest away from the engine assembly.

PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00 AND/OR P2A03)

(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 relating to the A/F sensor (DTCs for the A/F sensor heater or A/F sensor admittance) are output, troubleshoot those DTCs first.

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

2. PERFORM ACTIVE TEST USING TECHSTREAM (INJECTION VOLUME)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Turn the Techstream on.

(d) Warm up the engine and run the engine at an engine speed of 2500 rpm for approximately 90 seconds.

(e) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume / AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2.

(f) Perform the Control the Injection Volume operation with the engine idling.

(g) Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the Techstream.

HINT
- Change the fuel injection volume within the range of - 12.0% to +12.0%. The injection volume can be changed in fine gradations.
- 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:





Lean: During the Control the Injection Volume Active Test, the air fuel ratio sensor output voltage (AFS Voltage) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2S) is consistently below 0.4 V.

Rich: During the Control the Injection Volume Active Test, the AFS Voltage is consistently below 3.1 V, and the O2S is consistently higher than 0.55 V.

Lean/Rich: During the Control the Injection Volume Active Test, the output voltage of the heated oxygen sensor alternates correctly.

(h) Refer to "Data List / Active Test" [AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2] Data List / Active Test.

C -- REPLACE AIR FUEL RATIO SENSOR

B -- INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
A -- Continue to next step.

3. PERFORM CONFIRMATION DRIVING PATTERN

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

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

(e) Turn the engine switch off.

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

(g) Start the engine and warm it up.

(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

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

(j) Input the DTC: P2A00 or P2A03.

(k) Check the DTC judgment result.

Result





B -- REPLACE AIR FUEL RATIO SENSOR

A -- CHECK FOR INTERMITTENT PROBLEMS Check For Intermittent Problems

4. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) P0031

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

5. CHECK AIR INDUCTION SYSTEM

(a) Check the air induction system.

NG -- REPAIR OR REPLACE AIR INDUCTION SYSTEM
OK -- Continue to next step.

6. CHECK FUEL PRESSURE (FOR LOW PRESSURE SIDE)

(a) Check the fuel pressure (for low pressure side) Fuel System.

NG -- REPAIR OR REPLACE FUEL SYSTEM (FOR LOW PRESSURE SIDE)
OK -- Continue to next step.

7. CHECK FUEL PRESSURE (FOR HIGH PRESSURE SIDE)

(a) Check the fuel pressure (for high pressure side) Fuel System.

NG -- REPAIR OR REPLACE FUEL SYSTEM (FOR HIGH PRESSURE SIDE)
OK -- Continue to next step.

8. INSPECT FUEL INJECTOR (FOR PORT INJECTION)

(a) Inspect the fuel injector assembly for port injection Fuel Injector (for Port Injection).

NG -- REPLACE FUEL INJECTOR (FOR PORT INJECTION) Removal
OK -- Continue to next step.

9. INSPECT FUEL INJECTOR (FOR DIRECT INJECTION)

(a) Inspect the fuel injector assembly for direct injection Fuel Injector (for Direct Injection).

NG -- REPLACE FUEL INJECTOR (FOR DIRECT INJECTION) Removal
OK -- Continue to next step.

10. REPLACE AIR FUEL RATIO SENSOR

(a) Replace the air fuel ratio sensor Removal.

NEXT -- Continue to next step.

11. PERFORM CONFIRMATION DRIVING PATTERN

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

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

(e) Turn the engine switch off.

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

(g) Start the engine and warm it up.

(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

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

(j) Input the DTC: P2A00 or P2A03.

(k) Check the DTC judgment result.

Result





B -- END

A -- REPLACE ECM Removal
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