SFI SYSTEM, Diagnostic DTC:P0112, P0113

DTC Code DTC Name
P0112 Intake Air Temperature Circuit Low Input
P0113 Intake Air Temperature Circuit High Input

DESCRIPTION

A0054O7E01

The intake air temperature sensor, which is built into the mass air flow meter, monitors the intake air temperature. The intake air temperature sensor has a built-in thermistor with a resistance that varies according to the intake air temperature. When the intake air temperature becomes low, the resistance of the thermistor increases. When the temperature becomes high, the resistance drops. The intake air temperature sensor is powered by a 5 V supply from terminal THA of the ECM via resistor R. Since resistor R and the intake air temperature sensor are connected in series, when the resistance of the intake air temperature sensor changes depending on the intake air temperature, the voltage at terminal THA also varies accordingly. Based on this signal, the ECM increases the fuel injection volume when the engine is cold to improve driveability.

DTC No. DTC Detection Condition Trouble Area
P0112 A short in the intake air temperature sensor circuit for 0.5 seconds (1-trip detection logic).

  • Short in intake air temperature sensor circuit

  • Intake air temperature sensor (built into mass air flow meter)

  • ECM
P0113 An open in the intake air temperature sensor circuit for 0.5 seconds (1-trip detection logic).

  • Open in intake air temperature sensor circuit

  • Intake air temperature sensor (built into mass air flow meter)

  • ECM

Tech Tips

When any of these DTCs are output, check the intake air temperature using the intelligent tester. Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air.

Temperature Displayed Malfunction
-40°C (-40°F) Open circuit
140°C (284°F) Short circuit

WIRING DIAGRAM

A0058E2E01
*a Intake Air Temperature Sensor (Built into Mass Air Flow Meter)

CAUTION / NOTICE / HINT

Tech Tips

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. READ VALUE USING INTELLIGENT TESTER (INTAKE AIR TEMPERATURE)


    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 / Data List / Intake Air.

    5. Read the value displayed on the tester.

      Standard
      Same as actual intake air temperature.
      Result
      Result Proceed to
      Temperature displayed is -40°C (-40°F) A
      Temperature displayed is 140°C (284°F) or higher B
      Temperature displayed is same as actual intake air temperature C

      Tech Tips


      • If there is an open circuit, the intelligent tester indicates -40°C (-40°F).


      • If there is a short circuit, the intelligent tester indicates 140°C (284°F).


    B

    READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS) Click here

    C

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  2. READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)


    1. A0053MLE02
      Text in Illustration
      *1 Mass Air Flow Meter
      *2 ECM
      *3

      Front view of wire harness connector

      (to Mass Air Flow Meter)

      Confirm a good connection at the mass air flow meter.

    2. Disconnect the mass air flow meter connector.

    3. Connect terminals THA and ETHA of the wire harness connector for the mass air flow meter.

    4. Connect the intelligent tester to the DLC3.

    5. Turn the ignition switch to ON.

    6. Turn the tester on.

    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air.

    8. Read the value displayed on the tester.

      Standard value
      140°C (284°F)

    9. Reconnect the mass air flow meter connector.


    OK

    REPLACE MASS AIR FLOW METER Click here

    NG

  3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)


    1. Disconnect the mass air flow meter connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B2-1 (THA) - B39-87 (THA) Always Below 1 Ω
      B2-2 (E2) - B39-88 (ETHA) Always Below 1 Ω

    4. Reconnect the mass air flow meter connector.

    5. Reconnect the ECM connector.


    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - ECM)

  4. READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)


    1. A0056AYE16
      Text in Illustration
      *1 Mass Air Flow Meter
      *2 ECM

      Disconnect the mass air flow meter connector.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the tester on.

    5. Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air.

    6. Read the value displayed on the tester.

      Standard value
      -40°C (-40°F)

    7. Reconnect the mass air flow meter connector.


    OK

    REPLACE MASS AIR FLOW METER Click here

    NG

  5. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)


    1. Disconnect the mass air flow meter connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B2-1 (THA) or B39-87 (THA) - Body ground Always 10 kΩ or higher

    4. Reconnect the mass air flow meter connector.

    5. Reconnect the ECM connector.


    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - ECM)