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.

DTC Code DTC Detection Condition Trouble Area
P2A00 The calculated value of the Air Fuel ratio (A/F) sensor response rate deterioration level is less than the threshold (2 trip detection logic).

  • Open or short in Air Fuel ratio (A/F) (for Bank 1) sensor circuit

  • A/F sensor (for Bank 1)

  • ECM
P2A03 The calculated value of the Air Fuel ratio (A/F) sensor response rate deterioration level is less than the threshold (2 trip detection logic).

  • Open or short in A/F sensor (for Bank 2) circuit

  • A/F sensor (for Bank 2)

  • 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 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 A/F sensor response rate deterioration level is less than the threshold, the ECM interprets this as a malfunction and stores DTC(s).

A01EQLFE23

CONFIRMATION DRIVING PATTERN

Tech Tips

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

A01EON3E05

  1. Connect the intelligent tester to the DLC3.

  2. Turn the engine switch on (IG).

  3. Turn the tester 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. Start the engine and warn it up (until the engine coolant temperature 75°C (167°F)). [A]

  7. Turn the tester on.

  8. Drive the vehicle at a constant speed of between 60 km/h and 120 km/h (37 mph and 75 mph) for 10 minutes. [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 / Pending.

  10. Read the pending DTC.

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

    Tech Tips

    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 or P2A03.

  14. Check the DTC judgment result.

    Intelligent Tester
    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's memory limit

    Tech Tips


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

    • If the judgment result shows INCOMPLETE or UNKNOWN, perform step [B] and check the DTC judgment result again.

WIRING DIAGRAM

Refer to DTC P2195 Click here.

INSPECTION PROCEDURE

Tech Tips


  • DTC P2A00 and P2A03 are for Euro-OBD only.

  • Malfunctioning areas can be identified by performing the Control the Injection Volume function provided in the Active Test. The Control the Injection Volume function can help to determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.

  • The following instructions describe how to conduct the Control the Injection Volume 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 and run the engine at an engine speed of 2500 rpm for approximately 90 seconds.

  4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.

  5. Perform the Active Test operation with the engine idling.

  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


  • Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine gradations.

  • 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)

 +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

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 A01EQ75E05 A01EOHQE08 A01EQ75E05 A01EOEIE06 -
2 A01EQ75E05 A01ERBDE01 A01EQ75E05 A01EOEIE06

  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor circuit
3 A01EQ75E05 A01EOHQE08 A01EQ75E05 A01ERBDE01

  • Heated oxygen sensor

  • Heated oxygen sensor heater

  • Heated oxygen sensor circuit
4 A01EQ75E05 A01ERBDE01 A01EQ75E05 A01ERBDE01

  • Fuel injector assembly

  • Fuel pressure

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

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 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 the No. 1 cylinder.

  • Bank 2 refers to the bank that includes the No. 2 cylinder.

  • DTC P2A00 or P2A03 may be stored 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 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.

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 and ECT / DTC.

    5. Read DTCs.

      Result
      Result Proceed to
      P2A00 and/or P2A03 are output A
      P2A00 and/or P2A03 and other DTCs are output B

      Tech Tips

      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 Click here

    A

  2. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

    A01ERHXE06

    1. Disconnect the Air Fuel ratio (A/F) sensor connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (HA1A) - 2 (+B) 20°C (68°F) 1.8 to 3.4 Ω
      1 (HA1A) - 4 (A1A-) Always 10 kΩ or higher
      1 (HA2A) - 2 (+B) 20°C (68°F) 1.8 to 3.4 Ω
      1 (HA2A) - 4 (A2A-) Always 10 kΩ or higher

    NG

    REPLACE AIR FUEL RATIO SENSOR Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (ECM - AIR FUEL RATIO SENSOR)

    A01EQHJE03

    1. Disconnect the Air Fuel ratio (A/F) sensor connector.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      C47-2 (+B) - Body ground Engine switch on (IG) 11 to 14 V
      C48-2 (+B) - Body ground Engine switch on (IG) 11 to 14 V

    3. Turn the engine switch off.

    4. Disconnect the ECM connector.

    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      C47-1 (HA1A) - C53-22 (HA1A) Always Below 1 Ω
      C47-3 (A1A+) - C53-126 (A1A+) Always Below 1 Ω
      C47-4 (A1A-) - C53-125 (A1A-) Always Below 1 Ω
      C48-1 (HA2A) - C53-20 (HA2A) Always Below 1 Ω
      C48-3 (A2A+) - C53-103 (A2A+) Always Below 1 Ω
      C48-4 (A2A-) - C53-102 (A2A-) Always Below 1 Ω
      C47-1 (HA1A) or C53-22 (HA1A) - Body ground Always 10 kΩ or higher
      C47-3 (A1A+) or C53-126 (A1A+) - Body ground Always 10 kΩ or higher
      C47-4 (A1A-) or C53-125 (A1A-) - Body ground Always 10 kΩ or higher
      C48-1 (HA2A) or C53-20 (HA2A) - Body ground Always 10 kΩ or higher
      C48-3 (A2A+) or C53-103 (A2A+) - Body ground Always 10 kΩ or higher
      C48-4 (A2A-) or C53-102 (A2A-) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      C47-1 (HA1A) - C54-22 (HA1A) Always Below 1 Ω
      C47-3 (A1A+) - C54-126 (A1A+) Always Below 1 Ω
      C47-4 (A1A-) - C54-125 (A1A-) Always Below 1 Ω
      C48-1 (HA2A) - C54-20 (HA2A) Always Below 1 Ω
      C48-3 (A2A+) - C54-103 (A2A+) Always Below 1 Ω
      C48-4 (A2A-) - C54-102 (A2A-) Always Below 1 Ω
      C47-1 (HA1A) or C54-22 (HA1A) - Body ground Always 10 kΩ or higher
      C47-3 (A1A+) or C54-126 (A1A+) - Body ground Always 10 kΩ or higher
      C47-4 (A1A-) or C54-125 (A1A-) - Body ground Always 10 kΩ or higher
      C48-1 (HA2A) or C54-20 (HA2A) - Body ground Always 10 kΩ or higher
      C48-3 (A2A+) or C54-103 (A2A+) - Body ground Always 10 kΩ or higher
      C48-4 (A2A-) or C54-102 (A2A-) - Body ground Always 10 kΩ or higher
      A01ERWVE02

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. PERFORM CONFIRMATION DRIVING PATTERN


    NEXT

  5. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 AND/OR P2A03)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG) and turn the tester on.

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

    4. Read pending DTCs.

      Result
      Result Proceed to
      P2A00 and/or P2A03 is output A
      No DTC is output B

    B

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  6. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT

  7. PERFORM CONFIRMATION DRIVING PATTERN


    NEXT

  8. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 AND/OR P2A03)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG) and turn the tester on.

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

    4. Read pending DTCs.

      Result
      Result Proceed to
      No DTC is output A
      P2A00 and/or P2A03 are output B

    B

    REPLACE ECM Click here

    A

    END