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 (sensor 1)

  • Intake system

  • Fuel injector assembly

  • Fuel pump

  • Fuel line

  • ECM

Comes on

DTC stored

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 30 seconds or more 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.

A115363E55

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 4000 rpm

Air fuel ratio sensor status

Activated

Fuel-cut

Off

Engine load

10% or higher, and less than 70%

Shift position

2nd or more

Catalyst monitor

Not yet

Mass air flow

4.0 gm/sec or more, and less than 16 gm/sec

CONFIRMATION DRIVING PATTERN

Tip:

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

A231470E74

  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 and turn the GTS 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 (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.

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

  10. Read the pending DTCs.

    Tip:

    • 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.

    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
    Tip:

    • 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 DTC is output, perform the following procedure.

  14. 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.

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

  16. Read the pending DTCs.

    Tip:

    • 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.

    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
    Tip:

    • 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.

Tip:

  • 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.

  • 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)

    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.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTC P2A00 is output

      A

      DTC P2A00 and other DTCs are output

      B
      Tip:

      If any DTCs other than 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 / All Data / AFS Voltage B1S1 and O2S B1S2.

      Powertrain > Engine and ECT > Active Test

      Active Test Display

      Control the Injection Volume for A/F Sensor

      Data List Display

      AFS Voltage B1S1

      O2S B1S2

    6. Change the fuel injection volume using the GTS, and monitor the output voltage of the air fuel ratio sensor (AFS Voltage B1S1) and heated oxygen sensor (O2S B1S2) displayed on the GTS.

      Tip:

      • The Active Test "Control the Injection Volume for A/F Sensor" can be used to lower the fuel injection volume by 12.5% or increase the injection volume by 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.

      Table 1. Standard

      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: While performing the Active Test "Control the Injection Volume for A/F Sensor", 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: While performing the Active Test "Control the Injection Volume for A/F Sensor", the air fuel ratio sensor output voltage (AFS Voltage B1S1) is consistently below 3.1 V, and the heated oxygen sensor output voltage (O2S B1S2) is consistently higher than 0.55 V.

      • Lean/Rich: While performing the Active Test "Control the Injection Volume for A/F Sensor", the output voltage of the fuel ratio sensor (AFS Voltage B1S1) or heated oxygen sensor (O2S B1S2) alternates correctly.

      Tip:

      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 SENSORClick 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.

      Powertrain > Engine and ECT > Clear DTCs

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

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

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

      Powertrain > Engine and ECT > Utility

      Tester Display

      All Readiness

    8. Input the DTC: P2A00.

    9. 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

    REPLACE AIR FUEL RATIO SENSORClick here

  4. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

    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.

      Tip:

      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 FUEL PRESSURE

    1. Check the fuel pressure.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    INSPECT FUEL PUMPClick here

    OK

  7. INSPECT FUEL INJECTOR ASSEMBLY

    1. Inspect the fuel injector assembly.

      Click here

      Tip:

      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

  8. REPLACE AIR FUEL RATIO SENSOR

    1. Replace the air fuel ratio sensor.

      Click here

      Tip:

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

      Click here

    Result

    Proceed to

    NEXT
    NEXT

  9. 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.

      Powertrain > Engine and ECT > Clear DTCs

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

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

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

      Powertrain > Engine and ECT > Utility

      Tester Display

      All Readiness

    8. Input the DTC: P2A00.

    9. Check the DTC judgment result.

    Result

    Result

    Proceed to

    ABNORMAL

    (DTC P2A00 is output)

    A

    NORMAL

    (DTCs are not output)

    B
    B

    END

    A

  10. REPLACE ECM

    1. Replace the ECM.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

  11. 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.

      Powertrain > Engine and ECT > Clear DTCs

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

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

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

      Powertrain > Engine and ECT > Utility

      Tester Display

      All Readiness

    8. Input the DTC: P2A00.

    9. Check that the DTC judgment result is NORMAL.

    Result

    Proceed to

    NEXT
    NEXT

    END

  12. INSPECT FUEL PUMP

    1. Inspect the fuel pump.

      Click here

      Tip:

      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 hereClick here