SFI SYSTEM, Diagnostic DTC:P2A00

DTC Code DTC Name
P2A00 A/F Sensor Circuit Slow Response (Bank 1 Sensor 1)

DESCRIPTION

Refer to DTC P2195.

Click here

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P2A00 A/F Sensor Circuit Slow Response (Bank 1 Sensor 1) The calculated value for the air fuel ratio sensor response rate deterioration level is less than the threshold (2 trip detection logic).

  • Air fuel ratio sensor

  • EGR valve assembly

  • Intake system

  • Fuel injector assembly

  • Fuel pump

  • Fuel line

  • Gas leak from exhaust system

  • ECM

 Comes on (Euro-OBD) / - (Except Euro-OBD) DTC stored (Euro-OBD) / - (Except Euro-OBD)

MONITOR DESCRIPTION

After the 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 air fuel ratio control is performed for approximately 15 to 20 seconds after preconditions are met in order to measure the air fuel ratio sensor response rate. During active air fuel ratio control, the ECM forcibly increases and decreases the injection volume by a certain amount, based on the stoichiometric air fuel ratio learned during normal air fuel ratio control, and measures the air fuel ratio sensor response rate. The ECM receives a signal from the air fuel ratio sensor while performing active air fuel ratio control and uses it to calculate the air fuel ratio sensor response rate deterioration level.

If the value for the air fuel ratio sensor response rate deterioration level is less than the threshold, the ECM interprets this as a malfunction and stores the DTC.

A0048JXE59

MONITOR STRATEGY

Required Sensors/Components Air fuel ratio sensor
Frequency of Operation Once per driving cycle

TYPICAL ENABLING CONDITIONS

Active air fuel ratio control Performing
Active air fuel ratio control performed when following conditions met -
Engine coolant temperature 75°C (167°F) or higher
Idling OFF
Engine speed Less than 3600 rpm
Air fuel ratio sensor status Activated
Fuel cut OFF
Engine load 10% or higher, and less than 80%
Catalyst monitor Not yet
Mass air flow 5.2 gm/sec or more, and less than 30.0 gm/sec

CONFIRMATION DRIVING PATTERN

Tech Tips

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

A0048AIE21

  1. Connect the GTS to the DLC3.

  2. Turn the ignition switch to ON.

  3. Turn the GTS on.

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

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

  6. Turn the ignition switch to ON.

  7. Turn the GTS on.

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

  9. Drive the vehicle at approximately 60 km/h (37 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.

  10. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].

  11. Read the pending DTCs.

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  12. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  13. Input the DTC: P2A00.

  14. Check the DTC judgment result.

    GTS Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the test result is INCOMPLETE or N/A and no pending DTCs are output, perform the following procedure.

  15. Drive the vehicle at a speed between 75 and 100 km/h (47 and 62 mph) for 10 minutes [D].

    CAUTION:

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

  16. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [E].

  17. Read the pending DTCs.

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  18. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  19. Input the DTC: P2A00.

  20. Check the DTC judgment result.

    GTS Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • 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 N/A, drive the vehicle again under an increased load and then recheck the judgment result.

WIRING DIAGRAM

Refer to DTC P0031.

Click here

CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips


  • DTC P2A00 may be also stored when the air fuel ratio is stuck at rich or lean.

  • A low air fuel ratio sensor voltage could be caused by a rich air fuel mixture. Check for conditions that would cause the engine to run rich.

  • A high air fuel ratio 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 GTS. The ECM 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 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.

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    5. Read the DTCs.

      Result
      Result Proceed to
      DTC P2A00 is output A
      DTC P2A00 and other DTCs are output B

      Tech Tips

      If any DTCs other than DTC P2A00 are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)


    1. Connect the GTS to the DLC3.

    2. Start the engine.

    3. Turn the GTS on.

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

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / Data List / AFS Voltage B1S1 and O2S B1S2.

    6. Perform the Control the Injection Volume for A/F Sensor operation with the engine idling.

    7. Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the GTS.

      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.

      • Read the output voltage immediately after warming up the air fuel ratio sensor and heated oxygen sensor to avoid an inaccurate reading due to a sensor cooling.

      Tech Tips


      • The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 12.5%.

      • If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

      GTS Display (Sensor) Injection Volume Status Voltage

      AFS Voltage B1S1

      (Air fuel ratio)

      		 12.5% Rich Below 3.1 V
      -12.5% Lean Higher than 3.4 V

      O2S B1S2

      (Heated oxygen)

      		 12.5% Rich Higher than 0.55 V
      -12.5% Lean Below 0.4 V
      Result
      Status of AFS Voltage B1S1 Status of O2S B1S2 Air Fuel Ratio Condition and Air Fuel Ratio Sensor Condition Proceed to
      Lean/Rich Lean/Rich Normal A
      Lean Lean Actual air fuel ratio lean B
      Rich Rich Actual air fuel ratio rich
      Lean Lean/Rich Air fuel ratio sensor malfunction C
      Rich Lean/Rich Air fuel ratio sensor malfunction

      • Lean: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor output voltage (AFS Voltage B1S1) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2S B1S2) is consistently below 0.4 V.

      • Rich: During the Control the Injection Volume for A/F Sensor Active Test, AFS Voltage B1S1 is consistently below 3.1 V, and O2S B1S2 is consistently higher than 0.55 V.

      • Lean/Rich: During the Control the Injection Volume for A/F Sensor Active Test, the output voltage of the air fuel ratio sensor and heated oxygen sensor alternates correctly.

      Tech Tips

      Refer to "Data List / Active Test" [AFS Voltage B1S1 and O2S B1S2].

      Click here


    B

    INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) Click here

    C

    GO TO STEP 9 Click here

    A

  3. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.

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

    6. Turn the ignition switch to ON.

    7. Turn the GTS on.

    8. Start the engine and warm it up.

    9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    11. Input the DTC: P2A00.

    12. Check the DTC judgment result.

      Result
      Result Proceed to

      NORMAL

      (DTCs are not output)

      		 A

      ABNORMAL

      (DTC P2A00 is output)

      		 B

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

    B

    GO TO STEP 9 Click here

  4. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)


    1. Inspect the air fuel ratio sensor.

      Click here

      Tech Tips

      Perform "Inspection After Repair" after replacing the air fuel ratio sensor.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE AIR FUEL RATIO SENSOR Click here

    OK

  5. CHECK INTAKE SYSTEM


    1. Check the intake system for vacuum leaks.

      Click here

      OK
      No leaks in the intake system.

      Tech Tips

      Perform "Inspection After Repair" after repairing or replacing the intake system.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE INTAKE SYSTEM

    OK

  6. CHECK FOR EXHAUST GAS LEAK


    1. Check for exhaust gas leaks.

      Tech Tips

      Perform "Inspection After Repair" after repairing or replacing the exhaust system.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE EXHAUST SYSTEM

    OK

  7. CHECK FUEL PRESSURE


    1. Check the fuel pressure.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    INSPECT FUEL PUMP Click here

    OK

  8. INSPECT FUEL INJECTOR ASSEMBLY


    1. Inspect the fuel injector assembly (whether fuel volume is high or low, and whether injection pattern is poor).

      Click here

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel injector assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FUEL INJECTOR ASSEMBLY Click here

    OK

  9. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor.

      Click here

      Tech Tips

      Perform "Inspection After Repair" after replacing the air fuel ratio sensor.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  10. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.

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

    6. Turn the ignition switch to ON.

    7. Turn the GTS on.

    8. Start the engine and warm it up.

    9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    11. Input the DTC: P2A00.

    12. Check the DTC judgment result.

      Result
      Result Proceed to

      NORMAL

      (DTCs are not output)

      		 A

      ABNORMAL

      (DTC P2A00 is output)

      		 B

    A

    END

    B

  11. PERFORM ACTIVE TEST USING GTS (CONTROL THE EGR STEP POSITION)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

      Tech Tips

      The A/C switch and all accessory switches should be off.

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / MAP and Throttle Idle Position.

    6. Confirm that the Throttle Idle Position is ON and check the engine idling condition and MAP values in the Data List while performing the Active Test.

      OK
      MAP and idling condition change in response to EGR step position.
      - EGR Step Position (Active Test)
      0 Steps 0 to 30 Steps
      Idling condition Steady idling Idling changes from steady to rough idling

      MAP

      (Data List)

      MAP value is 20 to 48 kPa

      (150 to 360 mmHg)

      (EGR valve is fully closed)

      		 MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

      Note


      • Do not leave the EGR valve open for 10 seconds or more during the Active Test.

      • Be sure to return the EGR valve to step 0 when the Active Test is completed.

      • Do not open the EGR valve 30 steps or more during the Active Test.

      Tech Tips

      During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

      Result
      Proceed to
      OK
      NG

    OK

    GO TO STEP 14 Click here

    NG

    INSPECT EGR VALVE ASSEMBLY Click here

  12. INSPECT FUEL PUMP


    1. Inspect the fuel pump.

      Click here

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel pump.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPAIR OR REPLACE FUEL LINE

    NG

    REPLACE FUEL PUMP Click here

  13. INSPECT EGR VALVE ASSEMBLY


    1. Remove the EGR valve assembly.

      Click here

    2. Check if the EGR valve is stuck open.

      OK
      EGR valve is tightly closed

      Tech Tips

      Perform "Inspection After Repairs" after replacing the EGR valve assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EGR VALVE ASSEMBLY Click here

    OK

  14. REPLACE ECM


    1. Replace the ECM.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  15. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.

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

    6. Turn the ignition switch to ON.

    7. Turn the GTS on.

    8. Start the engine and warm it up.

    9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    11. Input the DTC: P2A00.

    12. Check that the DTC judgment result is NORMAL.

      Result
      Proceed to
      NEXT

    NEXT

    END