SFI SYSTEM, Diagnostic DTC:P2A00

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

DESCRIPTION

Tech Tips

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

Refer to DTC P2195 Click here.

DTC No. DTC Detection Condition Trouble Area
P2A00 The 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

CONFIRMATION DRIVING PATTERN

Tech Tips

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

A01DMAAE93

  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch to ON.

  3. Turn the tester on.

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

  5. Clear DTCs.

  6. Start the engine and warm it up. (Procedure "A")

  7. Drive the vehicle at a constant speed between 64 km/h and 120 km/h (40 mph and 75 mph) for 3 minutes or more. (Procedure "B")

  8. Turn the ignition switch off.

  9. Repeat steps Procedure "A" and "B" above again.

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

  11. Check if any DTCs (any pending DTCs) are output.

WIRING DIAGRAM

Refer to DTC P2195 Click here.

INSPECTION PROCEDURE

Tech Tips

Intelligent tester only:

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 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. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F sensor.

  5. Perform the Active Test operation with the engine idling (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) 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 12.5%.

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

Tester Display (Sensor) Injection Volume Status Voltage

AFS Voltage B1S1

(Air fuel ratio sensor)

+12.5% Rich Below 3.1 V

AFS Voltage B1S1

(Air fuel ratio sensor)

-12.5% Lean Higher than 3.4 V

O2S B1S2

(Heated oxygen sensor)

+12.5% Rich Higher than 0.55 V

O2S B1S2

(Heated oxygen sensor)

-12.5% 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

Output Voltage

Heated Oxygen Sensor

Output Voltage

Main Suspected Trouble Area
1 A01DTIDE23 A01DMIIE15 -
2 A01DMZLE18 A01DMIIE15
  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor circuit

3 A01DTIDE23 A01DMZLE18
  • Heated oxygen sensor

  • Heated oxygen sensor heater

  • Heated oxygen sensor circuit

  • Exhaust gas leakage

4 A01DMZLE18 A01DMZLE18
  • Fuel pressure

  • Exhaust gas leakage

    (air fuel ratio extremely lean or rich)


Tech Tips


  • DTC P2A00 may be stored 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. 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 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 tester on.

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

    5. Read DTCs.

      Result
      Result Proceed to
      DTC P2A00 is output A
      DTC P2A00 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
    A
  2. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)


    1. Inspect the air fuel ratio sensor Click here.


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


    1. Disconnect the air fuel ratio sensor connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      C56-2 (+B) - Body ground Ignition switch ON 11 to 14 V
    3. Turn the ignition switch off.

    4. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      C56-3 (A1A+) - C63-7 (A1A+) Always Below 1 Ω
      C56-4 (A1A-) - C63-1 (A1A-) Always Below 1 Ω
      C56-1 (HA1A) - C63-6 (HA1A) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      C56-3 (A1A+) or C63-7 (A1A+) - Body ground Always 10 kΩ or higher
      C56-4 (A1A-) or C63-1 (A1A-) - Body ground Always 10 kΩ or higher
      C56-1 (HA1A) or C63-6 (HA1A) - Body ground Always 10 kΩ or higher
    6. Reconnect the ECM connector.

    7. Reconnect the air fuel ratio sensor connector.


    NG
    OK
  4. PERFORM CONFIRMATION DRIVING PATTERN


    NEXT
  5. 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 tester on.

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

    5. Read DTCs.

      Result
      Result Proceed to
      DTC P2A00 is output A
      DTC is not output B

    B
    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)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

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

    5. Read DTCs.

      Result
      Result Proceed to
      DTC is not output A
      DTC P2A00 is output B

    B
    A