СИСТЕМА SFI, 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. DTC Detection Condition Trouble Area
P2A00 Calculated value of the air fuel ratio sensor response rate deterioration level is less than the threshold (2 trip detection logic).

  • Air fuel ratio sensor

  • ECM

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 A/F control is performed for approximately 10 seconds after the preconditions are met in order to measure the air fuel ratio 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 air fuel ratio sensor response rate. The ECM receives a signal from the air fuel ratio sensor while performing active A/F control and uses it to calculate the air fuel ratio sensor response rate deterioration level.

If 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.

A003CO0E44

MONITOR STRATEGY

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

TYPICAL ENABLING CONDITIONS

Active A/F control Executing
Active A/F control performed when following conditions met -
Engine coolant temperature 75°C (167°F) or higher
Idle OFF
Engine speed 1000 to 4000 rpm
Air fuel ratio sensor status Activated
Engine load 10 to 70%
Transmission gear 2nd or higher
Catalyst monitor Not executed
Intake air amount 4 to 16 gm/sec

CONFIRMATION DRIVING PATTERN

Tech Tips

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

A003B46E04

  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch to ON.

  3. Turn the intelligent tester on.

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

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

  6. Turn the ignition switch to ON and turn the intelligent tester on.

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

  8. 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.

  9. Enter the following menus: Powertrain / Engine and ECT / DTC [C].

  10. 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.

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

  12. Input the DTC: P2A00.

  13. Check the DTC judgment result.

    Intelligent tester 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, perform the following procedure.

  14. 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.

  15. Enter the following menus: Powertrain / Engine and ECT / DTC [E].

  16. 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.

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

  18. Input the DTC: P2A00.

  19. Check the DTC judgment result.

    Intelligent tester 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.

WIRING DIAGRAM

Refer to DTC P2237 Click here.

INSPECTION PROCEDURE

Tech Tips


  • Sensor 1 refers to the sensor mounted in front of the Three-way Catalytic Converter (TWC) and located near the engine assembly.

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

  • 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 intelligent tester. 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.

  • 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 FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

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

    5. Read DTCs.

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

      Tech Tips

      If any DTCs relating to the air fuel ratio sensor (DTCs for the air fuel ratio sensor heater or air fuel ratio sensor admittance) are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine.

    3. Turn the intelligent tester 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.

    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 intelligent tester.

      Tech Tips


      • Change the fuel injection volume within the range of -12.5% to +12.5%.

      • 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.

      Intelligent tester Display (Sensor) Injection Volume Status Voltage

      AFS Voltage B1S1

      (Air fuel ratio)

      		 +12.5% Rich Below 3.1 V

      AFS Voltage B1S1

      (Air fuel ratio)

      		 -12.5% Lean Higher than 3.4 V

      O2S B1S2

      (Heated oxygen)

      		 +12.5% Rich Higher than 0.59 V

      O2S B1S2

      (Heated oxygen)

      		 -12.5% Lean Below 0.21 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 B
      Lean Lean/Rich Air fuel ratio sensor malfunction C
      Rich Lean/Rich Air fuel ratio sensor malfunction C

      Lean: During the Control the Injection Volume for A/F Sensor 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 0.21 V.

      Rich: During the Control the Injection Volume for A/F Sensor Active Test, the AFS Voltage is consistently below 3.1 V, and the O2S is consistently higher than 0.59 V.

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

    8. 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

    REPLACE AIR FUEL RATIO SENSOR Click here

    A

  3. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Clear the DTCs Click here.

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

    6. Turn the ignition switch to ON and turn the intelligent tester on.

    7. Start the engine and warm it up.

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

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

    10. Input the DTC: P2A00.

    11. Check the DTC judgment result.

      Result
      Result Proceed to
      NORMAL (DTC is not output) A
      ABNORMAL (DTC P2A00 is output) B

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

    B

    REPLACE AIR FUEL RATIO SENSOR Click here

  4. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)


    1. Inspect the air fuel ratio sensor Click here.


    NG

    REPLACE AIR FUEL RATIO SENSOR Click here

    OK

  5. CHECK INTAKE SYSTEM


    1. Check the intake system.


    NG

    REPAIR OR REPLACE INTAKE SYSTEM

    OK

  6. CHECK FUEL PRESSURE


    1. Check the fuel pressure Click here.


    NG

    INSPECT FUEL PUMP Click here

    OK

  7. INSPECT FUEL INJECTOR ASSEMBLY


    1. Inspect the fuel injector assembly Click here.


    NG

    REPLACE FUEL INJECTOR ASSEMBLY Click here

    OK

  8. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT

  9. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Clear the DTCs Click here.

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

    6. Turn the ignition switch to ON and turn the intelligent tester on.

    7. Start the engine and warm it up.

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

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

    10. Input the DTC: P2A00.

    11. Check the DTC judgment result.

      Result
      Result Proceed to
      ABNORMAL (DTC P2A00 is output) A
      NORMAL (DTC is not output) B

    B

    END

    A

  10. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

  11. PERFORM CONFIRMATION DRIVING PATTERN


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Clear the DTCs Click here.

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

    6. Turn the ignition switch to ON and turn the intelligent tester on.

    7. Start the engine and warm it up.

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

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

    10. Input the DTC: P2A00.

    11. Check that the DTC judgment result is NORMAL.


    NEXT

    END

  12. INSPECT FUEL PUMP


    1. Inspect the fuel pump Click here.


    NG

    REPLACE FUEL PUMP Click here

    OK

    REPAIR OR REPLACE FUEL LINE