СИСТЕМА SFI, 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

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

(2-trip detection logic)

  • Open or short in air fuel ratio sensor circuit

  • Air fuel ratio sensor

  • EGR valve assembly

  • ECM

CONFIRMATION DRIVING PATTERN

Tech Tips

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

A011818E93

  1. Connect an 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 (Proceed to "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 (Proceed to "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 set.

WIRING DIAGRAM

A011BXOE05

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following 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 (A/F) 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. 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 in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume.)

  6. Monitor the output voltages of the A/F and HO2 sensors (AF 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 25%.

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

Tester Display (Sensor) Injection Volume Status Voltage

AF Voltage B1S1

(A/F)

 +25% Rich Less than 3.1 V

AF Voltage B1S1

(A/F)

 -12.5% Lean More than 3.4 V

O2S B1S2

(HO2)

 +25% Rich More than 0.55 V

O2S B1S2

(HO2)

 -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 A/F Sensor (Sensor 1) Output Voltage HO2 Sensor (Sensor 2) Output Voltage Main Suspected Trouble Area
1 A011AJ8E01 A011A4HE04 A011AJ8E01 A011AXVE01 -
2 A011AJ8E01 A0116WSE01 A011AJ8E01 A011AXVE01

  • A/F sensor

  • A/F sensor heater

  • A/F sensor circuit
3 A011AJ8E01 A011A4HE04 A011AJ8E01 A0116WSE01

  • HO2 sensor

  • HO2 sensor heater

  • HO2 sensor circuit
4 A011AJ8E01 A0116WSE01 A011AJ8E01 A0116WSE01

  • Injector

  • Fuel pressure

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

Tech Tips


  • DTC P2A00 may be 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 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)


    1. Connect an 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
      P2A00 A
      P2A00 and other DTCs 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. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (OPERATE EGR VALVE)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

      Tech Tips

      The A/C switch and all accessory switches should be off.

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.

    5. Check the MAP in Data List and the idling condition while performing Active Test.

      OK
      MAP and idling condition change in response to EGR step position.
      Standard
      - EGR Step Position (Active Test)
      0 Steps 0 to 30 Steps 30 to 40 Steps or Higher
      Idling condition Steady idling Engine changes from steady to rough idling Engine changes from rough idling to engine stall

      MAP value

      (Data List)

      28 to 48 kPa

      (EGR valve is fully closed)

      		 MAP value is at least +10 to 15 kPa higher than when EGR valve is fully closed

      80 to 110 kPa

      (After engine stall)

      Tech Tips


      • During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in EGR valve.

      Result
      Result Proceed to
      Outside standard range A
      Within standard range B

    B

    INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) Click here

    A

  3. CHECK WHETHER DTC OUTPUT RECURS (DTC P0401)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Clear the DTC.

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

    6. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

      Tech Tips

      The A/C switch and all accessory switches should be off.

    7. Switch the ECM from normal mode to check mode.

    8. Drive the vehicle at 60 km/h (37 mph) with the shift lever in B.

      CAUTION:


      • Strictly observe speed limits and traffic laws when performing the confirmation drive pattern.

    9. Perform fuel-cut operation for 5 seconds or more, with the accelerator pedal fully released.

      Tech Tips


      • If the deceleration was not completed, perform the confirmation driving pattern again.

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

    11. Input the DTCs to be confirmed.

    12. Check the DTC judgment result.

      Result
      Result Proceed to
      No output A
      P0401 B
      Intelligent Tester
      Tester Display Description
      NORMAL

      • DTC judgment completed

      • System normal
      ABNORMAL

      • DTC judgment completed

      • System abnormal
      INCOMPLETE

      • DTC judgment not completed

      • You should 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 DTC judgment result is INCOMPLETE or UNKNOWN, drive the vehicle again at 60 km/h (37 mph) with the shift lever in B, perform fuel-cut operation for 5 seconds or more with the accelerator pedal fully released, and check the DTC judgment result.


    B

    GO TO DTC CHART Click here

    A

  4. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)


    1. A011A2SE92
      Text in Illustration
      *1

      Component without harness connected:

      (Air Fuel Ratio Sensor)

      Disconnect the air fuel ratio 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

    3. Reconnect the air fuel ratio sensor.


    NG

    REPLACE AIR FUEL RATIO SENSOR Click here

    OK

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


    1. A011B8AE19
      Text in Illustration
      *1

      Front view of wire harness connector:

      (to Air Fuel Ratio Sensor)
      *2

      Front view of wire harness connector:

      (to ECM)

      Disconnect the air fuel ratio sensor connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      B34-2 (+B) - Body ground Ignition switch ON 11 to 14 V

    4. Turn the ignition switch off.

    5. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      B34-3 (A1A+) - B8-103 (A1A+) Always Below 1 Ω
      B34-4 (A1A-) - B8-126 (A1A-) Always Below 1 Ω
      B34-1 (HA1A) - B8-104 (HA1A) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B34-3 (A1A+) or B8-103 (A1A+) - Body ground Always 10 kΩ or higher
      B34-4 (A1A-) or B8-126 (A1A-) - Body ground Always 10 kΩ or higher
      B34-1 (HA1A) or B8-104 (HA1A) - Body ground Always 10 kΩ or higher

    7. Reconnect the ECM connector.

    8. Reconnect the air fuel ratio sensor connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. PERFORM CONFIRMATION DRIVING PATTERN


    NEXT

  7. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)


    1. Connect an 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
      P2A00 A
      No output B

    B

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  8. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT

  9. PERFORM CONFIRMATION DRIVING PATTERN


    NEXT

  10. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)


    1. Connect an 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
      No output A
      P2A00 B

    B

    REPAIR OR REPLACE CAUSE OF EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO Click here

    A

    END