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SFI SYSTEM, Diagnostic DTC:P0031, P0032, P0051, P0052, P101D, P103D

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DTC Code DTC Name
P0031 Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1)
P0032 Oxygen (A/F) Sensor Heater Control Circuit High (Bank 1 Sensor 1)
P0051 Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 2 Sensor 1)
P0052 Oxygen (A/F) Sensor Heater Control Circuit High (Bank 2 Sensor 1)
P101D A/F Sensor Heater Circuit Performance Bank 1 Sensor 1 Stuck ON
P103D A/F Sensor Heater Circuit Performance Bank 2 Sensor 1 Stuck ON
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CAUTION / NOTICE / HINT

Tip:

  • Although the DTC titles say the oxygen sensor, these DTCs relate to the air fuel ratio sensor.

  • Sensor 1 refers to the sensor mounted in front of the three-way catalytic converter and located near the engine assembly.

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DESCRIPTION

Refer to DTC P2195 (Click here).

Tip:

  • When any of these DTCs are set, the ECM enters fail-safe mode. The ECM turns off the air fuel ratio sensor heater in fail-safe mode. Fail-safe mode continues until the ignition switch is turned off.

  • The ECM provides a pulse width modulated control circuit to adjust the current through the heater. The air fuel ratio sensor heater circuit uses a relay on the +B side of the circuit.

DTC No. DTC Detection Condition Trouble Area

P0031

P0051

 Air fuel ratio sensor heater (bank 1, 2, sensor 1) current less than 0.8 A (1 trip detection logic)

  • Open in air fuel ratio sensor heater circuit

  • Air fuel ratio sensor heater (Bank 1, 2 sensor 1)

  • A/F relay

  • ECM

P0032

P0052

Air-Fuel Ratio (A/F) sensor heater (bank 1, 2, sensor 1) current fail

(1 trip detection logic)

  • Short in air fuel ratio sensor heater circuit

  • Air fuel ratio sensor heater (Bank 1, 2 sensor 1)

  • A/F relay

  • ECM

P101D

P103D

The heater current is higher than the specified value while the heater is no operating

(1 trip detection logic)

 ECM
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WIRING DIAGRAM

Refer to DTC P2195 (Click here).

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INSPECTION PROCEDURE

Note:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tip:

  • 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.

  • 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.

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PROCEDURE


  1. Click here

    INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)


    1. A017FGDE13

      Disconnect the air fuel ratio sensor connector.

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

      Standard resistance
      Bank 1
      Tester Connection Condition Specified Condition
      1 (HA1A) - 2 (+B) 20°C (68°F) 1.6 to 3.2 Ω
      1 (HA1A) - 4 (A1A-) Always 10 kΩ or higher
      Bank 2
      Tester Connection Condition Specified Condition
      1 (HA2A) - 2 (+B) 20°C (68°F) 1.6 to 3.2 Ω
      1 (HA2A) - 4 (A2A-) Always 10 kΩ or higher
      Table 1. Text in Illustration
      *1 Bank 1
      *2 Bank 2
      *a

      Component without harness connected

      (Air Fuel Ratio Sensor)

    3. Reconnect the air fuel ratio sensor connector.


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    CHECK TERMINAL VOLTAGE (+B OF AIR FUEL RATIO SENSOR)


    1. A017CAJE23

      Disconnect the air fuel ratio sensor connector.

    2. Turn the ignition switch on (IG).

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

      Standard voltage
      Bank 1
      Tester Connection Switch Condition Specified Condition
      B20-2 (+B) - Body ground Ignition switch on (IG) 11 to 14 V
      Bank 2
      Tester Connection Switch Condition Specified Condition
      B19-2 (+B) - Body ground Ignition switch on(IG) 11 to 14 V
      Table 2. Text in Illustration
      *1 Bank 1
      *2 Bank 2
      *a

      Front view of wire harness connector

      (to Air Fuel Ratio Sensor)

    4. Reconnect the air fuel ratio sensor connector.


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


    1. Disconnect the air fuel ratio sensor connector.

    2. Disconnect the ECM connector.

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

      Standard resistance (Check for open)
      Bank 1
      Tester Connection Condition Specified Condition
      B20-1 (HA1A) - B47-17 (HA1A) Always Below 1 Ω
      Bank 2
      Tester Connection Condition Specified Condition
      B19-1 (HA2A) - B47-19 (HA2A) Always Below 1 Ω
      Standard resistance (Check for short)
      Bank 1
      Tester Connection Condition Specified Condition
      B20-1 (HA1A) or B47-17 (HA1A) - Body ground Always 10 kΩ or higher
      Bank 2
      Tester Connection Condition Specified Condition
      B19-1 (HA2A) or B47-19 (HA2A) - Body ground Always 10 kΩ or higher

    4. Reconnect the ECM connector.

    5. Reconnect the air fuel ratio sensor connector.


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    CHECK WHETHER DTC OUTPUT RECURS


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs (Click here).

    5. Start the engine and idle it for 5 minutes or more.

    6. With the vehicle stationary, depress the accelerator pedal and maintain an engine speed of 3000 rpm for 1 minute.

    7. Idle the engine for 5 minutes or more.

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

    9. Read the DTCs.

      Result
      Display (DTC Output) Proceed to
      No output A
      P0031, P0032, P0051, P0052, P101D and/or P103D B

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    INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (A/F RELAY)


    1. Inspect the A/F relay (Click here).


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    CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - A/F RELAY)


    1. Disconnect the air fuel ratio sensor connector.

    2. Remove the engine room junction block assembly from the engine room relay block.

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

      Standard resistance (Check for open)
      Bank 1
      Tester Connection Condition Specified Condition
      B20-2 (+B) - 2A-4 Always Below 1 Ω
      Bank 2
      Tester Connection Condition Specified Condition
      B19-2 (+B) - 2A-4 Always Below 1 Ω
      Standard resistance (Check for short)
      Bank 1
      Tester Connection Condition Specified Condition
      B20-2 (+B) or 2A-4 - Body ground Always 10 kΩ or higher
      Bank 2
      Tester Connection Condition Specified Condition
      B19-2 (+B) or 2A-4 - Body ground Always 10 kΩ or higher

    4. Reconnect the air fuel ratio sensor connector.

    5. Reinstall the engine room junction block assembly.


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    REPLACE AIR FUEL RATIO SENSORClick here

  8. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR FUEL RATIO SENSOR - ECM)

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    REPLACE ECMClick here

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    CHECK FOR INTERMITTENT PROBLEMSClick here

  11. Click here

    REPLACE ENGINE ROOM JUNCTION BLOCK ASSEMBLYClick here

  12. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - A/F RELAY)