SFI SYSTEM, Diagnostic DTC:P2A00, P2A03

DTC Code DTC Name
P2A00 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 Click here.

Tech Tips


  • DTC P2A00 indicates malfunctions related to the bank 1 air fuel ratio sensor.

  • DTC P2A03 indicates malfunctions related to the bank 2 air fuel ratio 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.

DTC No. DTC Detection Condition Trouble Area

P2A00

P2A03

 Calculated value for air-fuel ratio sensor response rate deterioration level is less than threshold

  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • ECM

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 air fuel ratio control is performed for approximately 10 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 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 air fuel ratio sensor response rate deterioration level is less than the threshold, the ECM interprets this as a malfunction and sets the DTC.

A0160RVE38

CONFIRMATION DRIVING PATTERN

Tech Tips

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

A015YSQE01

  1. Connect the intelligent tester to the DLC3.

  2. Turn the engine switch on (IG).

  3. Turn the tester on.

  4. Clear DTCs.

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

  6. Turn the engine switch on (IG) and turn the 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 / 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 / Utility / All Readiness.

  12. Input the DTC: P2A00 or P2A03.

  13. Check the DTC judgment result.

    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
    UNKNOWN

    • 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 UNKNOWN, 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 / 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 / Utility / All Readiness.

  18. Input the DTC: P2A00 or P2A03.

  19. Check the DTC judgment result.

    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
    UNKNOWN

    • 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 P2195 Click here.

INSPECTION PROCEDURE

Tech Tips

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 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 intelligent tester.


  1. Connect the intelligent tester to the DLC3.

  2. Start the engine and turn the tester on.

  3. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.

  4. On the tester, enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor.

  5. Perform the Active Test operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume).

  6. 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 tester.

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 25%.

  • Each sensor reacts in accordance with increases and decreases in the fuel injection volume.

Tester Display (Sensor) Injection Volume Status Voltage

AFS Voltage B1S1 or AFS Voltage B2S1

(Air fuel ratio)

 +25% Rich Less than 3.1 V

AFS Voltage B1S1 or AFS Voltage B2S1

(Air fuel ratio)

 -12.5% Lean More than 3.4 V

O2S B1S2 or O2S B2S2

(Heated oxygen)

 +25% Rich More than 0.55 V

O2S B1S2 or O2S B2S2

(Heated oxygen)

 -12.5% Lean Less than 0.4 V

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.

Case Air Fuel Ratio Sensor (Sensor 1) Output Voltage Heated Oxygen Sensor (Sensor 2) Output Voltage Main Suspected Trouble Area
1 A0162ADE01 A0160FEE04 A0162ADE01 A0161P9E01 -
2 A0162ADE01 A015ZP2E01 A0162ADE01 A0161P9E01

  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor circuit
3 A0162ADE01 A0160FEE04 A0162ADE01 A015ZP2E01

  • Heated oxygen sensor

  • Heated oxygen sensor heater

  • Heated oxygen sensor circuit
4 A0162ADE01 A015ZP2E01 A0162ADE01 A015ZP2E01

  • Injector

  • Fuel pressure

  • Gas leaks from exhaust system (Air-fuel ratio extremely rich or lean)

Tech Tips


  • DTC P2A00 or P2A03 may be also set, when the air-fuel ratio is stuck 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 intelligent tester. 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)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

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

    5. Read the DTCs.

      Result
      Display (DTC Output) Proceed to
      P2A00 and/or P2A03 A
      P2A00 and/or P2A03 and other DTCs B

      Tech Tips

      If any DTCs relating to the air fuel ratio sensor (DTCs for the air fuel ratio sensor heater) 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 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 / Active Test / Control the Injection Volume.

    6. Perform the Control the Injection Volume 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 or AFS Voltage B2S1 and O2S B2S2) displayed on the tester.

      Tech Tips


      • 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.

      Tester Display (Sensor) Injection Volume Status Voltage

      AFS Voltage B1S1 or AFS Voltage B2S1

      (Air fuel ratio)

      		 +12% Rich Below 3.1 V

      AFS Voltage B1S1 or AFS Voltage B2S1

      (Air fuel ratio)

      		 -12% Lean Higher than 3.4 V

      O2S B1S2 or O2S B2S2

      (Heated oxygen)

      		 +12% Rich Higher than 0.55 V

      O2S B1S2 or O2S B2S2

      (Heated oxygen)

      		 -12% Lean Below 0.4 V
      Result
      Status of AFS Voltage B1S1 or AFS Voltage B2S1 Status of O2S B1S2 or O2S B2S2 Air Fuel Ratio Condition and Air Fuel Ratio Sensor Condition Misfire Suspected Trouble Area Proceed to
      Lean/Rich Lean/Rich Normal - - A
      Lean Lean Actual air fuel ratio lean May occur

      • PCV valve and hose

      • PCV hose connections

      • Fuel injector blockage

      • Gas leaks from exhaust system

      • Intake system

      • Fuel pressure

      • Mass air flow meter assembly

      • Engine coolant temperature sensor

      		 B
      Rich Rich Actual air fuel ratio rich -

      • Fuel injector leakage or blockage

      • Gas leaks from exhaust system

      • Ignition system

      • Fuel pressure

      • Mass air flow meter assembly

      • Engine coolant temperature sensor

      		 B
      Lean Lean/Rich Air fuel ratio sensor malfunction - Air fuel ratio sensor C
      Rich Lean/Rich Air fuel ratio sensor malfunction - Air fuel ratio sensor C

      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.

    8. Refer to "Data List / Active Test" [AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2] Click here.


    B

    INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) Click here

    C

    REPLACE AIR FUEL RATIO SENSOR Click here

    A

  3. PERFORM CONFIRMATION DRIVING PATTERN


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Turn the engine switch off.

    6. Turn the engine switch on (IG) and turn the 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 / Utility / All Readiness.

    10. Input the DTC: P2A00 or P2A03.

    11. Check the DTC judgment result.

      Result
      Result Proceed to
      NORMAL (DTC is not output) A
      ABNORMAL (DTC P2A00 or P2A03 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)


    NG

    REPLACE AIR FUEL RATIO SENSOR Click here

    OK

  5. CHECK INTAKE SYSTEM


    1. Check the intake system Click here.


    NG

    REPAIR OR REPLACE INTAKE SYSTEM

    OK

  6. CHECK FUEL PRESSURE (FOR LOW PRESSURE SIDE)


    1. Check the fuel pressure (for low pressure side) Click here.


    NG

    REPAIR OR REPLACE FUEL SYSTEM (FOR LOW PRESSURE SIDE)

    OK

  7. CHECK FUEL PRESSURE (FOR HIGH PRESSURE SIDE)


    1. Check the fuel pressure (for high pressure side) Click here.


    NG

    REPAIR OR REPLACE FUEL SYSTEM (FOR HIGH PRESSURE SIDE)

    OK

  8. INSPECT FUEL INJECTOR (FOR PORT INJECTION)


    1. Inspect the fuel injector assembly for port injection Click here.


    NG

    REPLACE FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION) Click here

    OK

  9. INSPECT FUEL INJECTOR (FOR DIRECT INJECTION)


    1. Inspect the fuel injector assembly for direct injection Click here.


    NG

    REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION) Click here

    OK

  10. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT

  11. PERFORM CONFIRMATION DRIVING PATTERN


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Turn the engine switch off.

    6. Turn the engine switch on (IG) and turn the 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 / Utility / All Readiness.

    10. Input the DTC: P2A00 or P2A03.

    11. Check the DTC judgment result.

      Result
      Result Proceed to
      ABNORMAL (DTC P2A00 or P2A03 is output) A
      NORMAL (DTC is not output) B

    B

    END

    A

    REPLACE ECM Click here