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

A01VL0RE03

The intake air temperature sensor is built into the manifold absolute pressure sensor, and monitors the intake air temperature. The intake air temperature sensor has a built-in thermistor that varies its resistance depending on the temperature of the intake air. When the air temperature is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. The variations in resistance are reflected in the voltage applied to the ECM terminal (See Fig 1).

The intake air temperature sensor is connected to the ECM. The 5 V power source voltage in the ECM is applied to the intake air temperature sensor from terminal THA via resistor R.

Resistor R and the intake air temperature sensor are connected in series. When the resistance value of the intake air temperature sensor changes in accordance with changes in the intake air temperature, the voltage at terminal THA also changes. Based on this signal, the ECM increases the fuel injection volume to improve the driveability during cold engine operation.

Tech Tips

When the intake air temperature sensor output is outside the normal range, the ECM determines this to be a malfunction.

DTC No. DTC Detecting Condition Trouble Area
P0112 Intake air temperature sensor output is less than -47°C (-53°F) for 255.5 seconds (3 trip detection logic)

  • Open or short in intake air temperature sensor circuit

  • Short to power source circuit

  • Intake air temperature sensor (built into manifold absolute pressure sensor)

  • ECM
P0113

Intake air temperature sensor output is more than 140°C (284°F) for 255.5 seconds

(3 trip detection logic)

  • Short in intake air temperature sensor circuit

  • Intake air temperature sensor (built into manifold absolute pressure sensor)

  • ECM

Tech Tips


  • DTC P0112 and P0113 are detected when the engine idles for approximately 5 minutes.

  • 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) or higher Short circuit

WIRING DIAGRAM

A01VF3SE01
*a Intake Air Temperature Sensor
*b (Built into Manifold Absolute Pressure Sensor)

CAUTION / NOTICE / HINT

Note

Perform electronic throttle learning after replacing the ECM Click here.

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)


    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.

      OK
      Same as actual intake air temperature.
      Result
      Result Proceed to
      -40°C (-40°F) A
      140°C (284°F) or higher B
      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) or higher.


    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)

    A01VHIAE01
    Text in Illustration
    *1 Manifold Absolute Pressure Sensor
    *2 ECM
    *a

    Front view of wire harness connector

    (to Manifold Absolute Pressure Sensor)

    1. Disconnect the manifold absolute pressure sensor connector.

    2. Connect terminals 4 (THA) and 2 (E2) of the manifold absolute pressure sensor wire harness side.

    3. Connect the intelligent tester to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the tester on.

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

    7. Read the value displayed on the tester.

      Standard value
      140°C (284°F) or higher

    OK

    REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here

    NG

  3. CHECK HARNESS AND CONNECTOR (MANIFOLD ABSOLUTE PRESSURE SENSOR - ECM)


    1. Disconnect the manifold absolute pressure sensor 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
      B91-4 (THA) - B87-13 (THA) Always Below 1 Ω
      B91-2 (E2) - B87-51 (EPIM) Always Below 1 Ω

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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

    A01VHTYE02
    Text in Illustration
    *1 Manifold Absolute Pressure Sensor
    *2 ECM

    1. Disconnect the manifold absolute pressure sensor 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)

    OK

    REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here

    NG

  5. CHECK HARNESS AND CONNECTOR (MANIFOLD ABSOLUTE PRESSURE SENSOR - ECM)


    1. Disconnect the manifold absolute pressure sensor 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
      B91-4 (THA) or B87-13 (THA) - Body ground Always 10 kΩ or higher

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR