Dtc P0112 Intake Air Temperature Circuit Low Input

Engine Hybrid System. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25
2Tr-Fbe Engine Control. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (INTAKE AIR TEMPERATURE)

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

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

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

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

DTC P0112 Intake Air Temperature Circuit Low Input

DTC P0113 Intake Air Temperature Circuit High Input


DESCRIPTION

Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.2Tr-Fbe Engine Control.Sfi System. Dtc P0112 Intake Air Temperature Circuit Low Input
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).
  1. Short in intake air temperature sensor circuit
  2. Intake air temperature sensor (built into mass air flow meter)
  3. ECM
P0113
An open in the intake air temperature sensor circuit for 0.5 seconds (1-trip detection logic).
  1. Open in intake air temperature sensor circuit
  2. Intake air temperature sensor (built into mass air flow meter)
  3. ECM

HINT:
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


Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.2Tr-Fbe Engine Control.Sfi System. Dtc P0112 Intake Air Temperature Circuit Low Input


INSPECTION PROCEDURE

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

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

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

  1. Read the value displayed on the tester.

    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
    HINT:
    1. If there is an open circuit, the intelligent tester indicates -40°C (-40°F).
    2. If there is a short circuit, the intelligent tester indicates 140°C (284°F).


B
Go to step 4

C
CHECK FOR INTERMITTENT PROBLEMS (HILUX_TGN26 RM000000PDQ0YMX.html)
A


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


    Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.2Tr-Fbe Engine Control.Sfi System. Dtc P0112 Intake Air Temperature Circuit Low Input

  1. Confirm that there is a good connection at the mass air flow meter.

  1. Disconnect the mass air flow meter connector.

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

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

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

  1. Read the value displayed on the tester.

    Standard value:
    140°C (284°F)
    Text in Illustration
    *1
    		Mass Air Flow Meter
    *2
    		ECM
    *a
    		Front view of wire harness connector
    (to Mass Air Flow Meter)

  1. Reconnect the mass air flow meter connector.



NG
Go to step 3
OK

REPLACE MASS AIR FLOW METER (HILUX_TGN26 RM000000VW602DX.html)

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

  1. Disconnect the mass air flow meter connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    C36-4 (THA) - C95-12 (THA)
    		Always
    		Below 1 Ω
    C36-5 (E2) - C95-11 (ETHA)
    		Always
    		Below 1 Ω

  1. Reconnect the mass air flow meter connector.

  1. Reconnect the ECM connector.



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

REPLACE ECM (HILUX_TGN26 RM000000VW2024X.html)

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


    Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.2Tr-Fbe Engine Control.Sfi System. Dtc P0112 Intake Air Temperature Circuit Low Input

  1. Disconnect the mass air flow meter connector.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

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

  1. Read the value displayed on the tester.

    Standard value:
    -40°C (-40°F)
    Text in Illustration
    *1
    		Mass Air Flow Meter
    *2
    		ECM

  1. Reconnect the mass air flow meter connector.



NG
Go to step 5
OK

REPLACE MASS AIR FLOW METER (HILUX_TGN26 RM000000VW602DX.html)

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

  1. Disconnect the mass air flow meter connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    C36-4 (THA) or C95-12 (THA) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the mass air flow meter connector.

  1. Reconnect the ECM connector.



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

REPLACE ECM (HILUX_TGN26 RM000000VW2024X.html)