ECD SYSTEM, Diagnostic DTC:23

DTC Code DTC Name
23 Air Temperature Circuit Malfunction

DESCRIPTION

The intake air temperature sensor senses the intake air temperature. A thermistor built into this sensor changes the resistance value according to the intake air temperature as shown in the illustration. The resistance value of the intake air temperature sensor is one of the factors used to determine the fuel injection volume.

A01DZUUE06
DTC No. DTC Detection Condition Trouble Area
23 Open or short in intake air temperature sensor circuit for 0.5 sec. or more

  • Open or short in intake air temperature sensor circuit

  • Intake air temperature sensor

  • ECM

WIRING DIAGRAM

A01DV37E02

INSPECTION PROCEDURE

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 be open.

  • 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.

When using intelligent tester:

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch ON.

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

      Result
      Display Proceed to
      -40°C (-40°F) A
      140°C (284°F) or more B
      The same as actual engine coolant temperature C

      Tech Tips

      When DTC 23 is present, the type of malfunction can be determined based on the intake air temperature (see below)

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

    B

    CHECK WIRE HARNESS (FOR SHORT) Click here

    C

    CHECK FOR INTERMITTENT PROBLEMS

    A

  2. CHECK WIRE HARNESS (FOR OPEN)


    1. A01DWF8E03

      Disconnect the I3 intake air temperature sensor connector.

    2. Connect terminals 1 and 2 of the intake air temperature sensor harness side connector.

    3. Turn the ignition switch ON.

    4. Read the temperature value on the intelligent tester.

      Temperature
      140°C (284°F) or more

    OK

    REPLACE INTAKE AIR TEMPERATURE SENSOR

    NG

  3. CHECK ECM (FOR OPEN)


    1. A01DVSUE07

      Connect between terminals THA and E2 of the ECM connector.

    2. Turn the ignition switch ON.

    3. Read the temperature value on the intelligent tester.

      Temperature
      140°C (284°F) or more

    NG

    REPLACE ECM

    OK

    REPAIR OR REPLACE HARNESS AND CONNECTOR

  4. CHECK WIRE HARNESS (FOR SHORT)


    1. A01E1D2E02

      Disconnect the intake air temperature sensor connector.

    2. Turn the ignition switch ON.

    3. Read the temperature value on the intelligent tester.

      Temperature
      -40°C (-40°F)

    OK

    REPLACE INTAKE AIR TEMPERATURE SENSOR

    NG

  5. CHECK ECM (FOR SHORT)


    1. A01E0XZE08

      Disconnect the E22 ECM connector.

    2. Turn the ignition switch ON.

    3. Read the temperature value on the intelligent tester.

      Temperature
      -40°C (-40°F)

    NG

    REPLACE ECM

    OK

    REPAIR OR REPLACE HARNESS AND CONNECTOR

When not using intelligent tester:

PROCEDURE


  1. CHECK ECM


    1. A01E2VTE45

      Turn the ignition switch ON.

    2. Measure the voltage of the ECM connector.

      Standard voltage
      Tester Connection Condition Specified Condition
      E22-3 (THA) - E2 (E22-9) 20°C (68°F) 0.2 to 3.8 V
      E22-3 (THA) - E2 (E22-9) 80°C (176°F) 0.1 to 1.5 V

    OK

    CHECK FOR INTERMITTENT PROBLEMS

    NG

  2. INSPECT INTAKE AIR TEMPERATURE SENSOR


    1. A01DWUME01

      Measure the resistance of the intake air temperature sensor.

      OK
      The resistance value is within the acceptable range shown in the illustration.

    NG

    REPLACE INTAKE AIR TEMPERATURE SENSOR

    OK

  3. CHECK WIRE HARNESS (ECM - INTAKE AIR TEMPERATURE SENSOR)


    1. A01E0J3E03

      Disconnect the I3 intake air temperature sensor connector.

    2. Disconnect the E22 ECM connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition
      I3-2 - E22-3 (THA) Below 1 Ω
      I3-1 - E22-9 (E2) Below 1 Ω
      E22-3 (THA) - E22-9 (E2) 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE ECM