ECD SYSTEM, Diagnostic DTC:P0112, P0113

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

DESCRIPTION

The intake air temperature sensor is built into the mass air flow meter sub-assembly and senses the atmospheric temperature. A thermistor built into the sensor changes the resistance value according to the intake air temperature. The lower the atmospheric temperature is, the greater the thermistor resistance value is, and the higher the atmospheric temperature is, the lower the thermistor resistance value is (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. The 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 driveability during cold engine operation.

A01CIE2E05
P0112
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
Ignition switch ON for 0.5 seconds Short in intake air temperature sensor circuit for 0.5 seconds (1 trip detection logic).

  • Open or short in intake air temperature sensor circuit

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

  • ECM
P0113
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
Ignition switch ON for 0.5 seconds Open in intake air temperature sensor circuit for 0.5 seconds (1 trip detection logic).

  • Open or short in intake air temperature sensor circuit

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

  • ECM

Tech Tips

When DTC P0112 or P0113 is detected, check the intake air temperature by entering the following menus using the intelligent tester: 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

A01CGODE01

INSPECTION PROCEDURE

Note

After replacing the ECM, the new ECM needs registration Click here and initialization Click here.

Tech Tips


  • If DTCs that are related to different systems are output simultaneously while terminal E2 is used as a ground terminal, terminal E2 may have an open circuit.

  • 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 moving or stationary, whether the engine was warmed up or not, as well as other data recorded at the time of a malfunction.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (INTAKE AIR TEMPERATURE)


    1. Replace the normal DLC3 cable (12 V specification) for the intelligent tester with the 24 V DLC3 cable.

      Note

      Be sure to use the 24 V DLC3 cable when connecting the intelligent tester to the DLC3. Using the normal DLC3 cable (12 V specification) will cause damage to the tester.

    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.

      Standard
      Same value as the actual inlet air temperature.
      Result
      Temperature Display Proceed to
      -40°C (-40°F) A
      140°C (284°F) B
      OK (same as air temperature near intake manifold) 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. A01CI89E12
      Text in Illustration
      *1 Intake Air Temperature Sensor
      *2 ECM
      *a

      Front view of wire harness connector

      (to Mass Air Flow Meter Sub-assembly)

      Disconnect the mass air flow meter sub-assembly connector.

    2. Connect terminals 1 (THA) and 2 (E2) of the mass air flow meter sub-assembly wire harness side connector.

    3. Replace the normal DLC3 cable (12 V specification) for the intelligent tester with the 24 V DLC3 cable.

      Note

      Be sure to use the 24 V DLC3 cable when connecting the intelligent tester to the DLC3. Using the normal DLC3 cable (12 V specification) will cause damage to the tester.

    4. Connect the intelligent tester to the DLC3.

    5. Turn the ignition switch to ON.

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

    7. Read the value.

      Standard
      140°C (284°F)

    8. Reconnect the mass air flow meter sub-assembly connector.


    NG

    CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) Click here

    OK

    REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Click here

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


    1. Disconnect the mass air flow meter sub-assembly connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      I23-1 (THA) - E35-10 (THA) Always Below 1 Ω
      I23-2 (E2) - E35-14 (E21) Always Below 1 Ω

    4. Reconnect the mass air flow meter sub-assembly connector.

    5. Reconnect the ECM connector.


    NG

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

    OK

    REPLACE ECM Click here

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


    1. A01CGKRE67
      Text in Illustration
      *1 Intake Air Temperature Sensor
      *2 ECM

      Disconnect the mass air flow meter sub-assembly connector.

    2. Replace the normal DLC3 cable (12 V specification) for the intelligent tester with the 24 V DLC3 cable.

      Note

      Be sure to use the 24 V DLC3 cable when connecting the intelligent tester to the DLC3. Using the normal DLC3 cable (12 V specification) will cause damage to the tester.

    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.

      Standard
      -40°C (-40°F)

    8. Reconnect the mass air flow meter sub-assembly connector.


    NG

    CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) Click here

    OK

    REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Click here

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


    1. Disconnect the mass air flow meter sub-assembly connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      I23-1 (THA) or E35-10 (THA) - Body ground Always 10 kΩ or higher
      I23-2 (E2) or E35-14 (E21) - Body ground Always 10 kΩ or higher

    4. Reconnect the mass air flow meter sub-assembly connector.

    5. Reconnect the ECM connector.


    NG

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

    OK

    REPLACE ECM Click here