SFI SYSTEM, Diagnostic DTC:P0112

DTC Code DTC Name
P0112 Intake Air Temperature Sensor 1 Circuit Low Bank 1

DESCRIPTION

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0112 Intake Air Temperature Sensor 1 Circuit Low Bank 1

Enable Criteria


  • Engine running

Malfunction Criteria


  • Voltage at ECU less than 0.049 V for time 1.5 seconds or more

Diagnostic Mask


  • The MIL will be illuminated if these faults are present for 2 consecutive trips

Monitor


  • Continuous

Potential failure modes


  • Signal short circuit

  • Sensor failure

  • Short in intake air temperature sensor circuit

  • Wire harness or connector

  • Intake air temperature sensor (mass air flow meter)

  • ECM

 Comes on DTC stored

MONITOR DESCRIPTION

The combined sensor which measures both Mass Air Flow (MAF) and Intake Air Temperature (IAT) is incorporated into the air box. The IAT sensor is a thermistor device which changes resistance with temperature. As air intake temperature decreases the thermistor resistance value increases, and conversely as air temperature increases so the thermistor resistance value decreases.

WIRING DIAGRAM

B004586E02
*a Intake Air Temperature Sensor (Mass Air Flow Meter)

CAUTION / NOTICE / HINT

Tech Tips

Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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 GTS (INTAKE AIR)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine / Data List / Intake Air.

    5. Read the value displayed on the GTS.

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

      Tech Tips


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

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


    B

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

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


    1. Disconnect the mass air flow meter connector.

      B0047JEC01
      *1 Mass Air Flow Meter *2 ECM
      *a

      Front view of wire harness connector

      (to Mass Air Flow Meter)

      		 - -

    2. Connect terminals 4 (THA) and 2 (E2) of the mass air flow meter connector on the wire harness side.

    3. Connect the GTS to the DLC3.

    4. Turn the engine switch on (IG).

    5. Turn the GTS on.

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

    7. Read the value displayed on the GTS.

      Standard Value
      140°C (284°F)

      Tech Tips

      Perform "Inspection After Repair" after replacing the mass air flow meter.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MASS AIR FLOW METER Click here

    NG

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


    1. Disconnect the B142 ECM connector.

    2. Disconnect the A117 mass air flow meter connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B142-17 (THA) - A117-4 (THA) Always Below 1 Ω
      B142-9 (E2) - A117-2 (E2) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR