Dtc P0112 Intake Air Temperature Circuit Low Input

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

DESCRIPTION

MONITOR DESCRIPTION

MONITOR STRATEGY

CONFIRMATION DRIVING PATTERN

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (INTAKE AIR)

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-Fe Engine Control.Sfi System (W/ Secondary Air Injection System). Dtc P0112 Intake Air Temperature Circuit Low Input
  1. The intake air temperature sensor, mounted on 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 temperature of the intake air. When the intake air temperature is low, the resistance of the thermistor increases. When the temperature is high, the resistance drops. These variations in resistance are transmitted to the ECM as voltage changes (see Fig. 1).
  2. The intake air temperature sensor is powered by a 5 V supply from the THA terminal of the ECM, via resistor R.
  3. Resistor R and the intake air temperature sensor are connected in series. When the resistance value of the intake air temperature sensor changes according to changes in the intake air temperature, the voltage at terminal THA also varies. Based on this signal, the ECM increases the fuel injection volume when the engine is cold to improve driveability.
    HINT:
    When DTC P0112 or P0113 is stored, the ECM enters fail-safe mode. During fail-safe mode, the intake air temperature is estimated to be 20°C (68°F) by the ECM. The ECM continues operating in fail-safe mode until a pass condition is detected.

DTC No.
DTC Detection Condition
Trouble Area
P0112
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
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 either of these DTCs is stored, check the intake air temperature by entering the following menus: Powertrain / Engine and ECT / All Data / Intake Air.

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

MONITOR DESCRIPTION

The ECM monitors the sensor voltage and uses this value to calculate the intake air temperature. When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a malfunction in the intake air temperature sensor and stores a DTC.
Example:
If the sensor output voltage is higher than 4.91 V for 0.5 seconds or more, the ECM determines that there is an open in the intake air temperature sensor circuit and stores DTC P0113. Conversely, if the output voltage is below 0.18 V for 0.5 seconds or more, the ECM determines that there is a short in the sensor circuit and stores DTC P0112.
If the malfunction is not repaired successfully, a DTC is stored 0.5 seconds after the engine is next started.

MONITOR STRATEGY


Frequency of Operation
Continuous

CONFIRMATION DRIVING PATTERN

  1. Turn the ignition switch to ON and wait for 5 seconds or more.

WIRING DIAGRAM


Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.2Tr-Fe Engine Control.Sfi System (W/ Secondary Air Injection 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)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

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

  1. Read the value displayed on the intelligent 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
    HINT:
    1. If there is an open circuit, the intelligent tester indicates -40°C (-40°F).
    1. If there is a short circuit, the intelligent tester indicates 140°C (284°F) or higher.


B
Go to step 4

C
CHECK FOR INTERMITTENT PROBLEMS (HILUX_TGN26 RM000000PDQ0PUX.html)
A


2.READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)
Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.2Tr-Fe Engine Control.Sfi System (W/ Secondary Air Injection System). Dtc P0112 Intake Air Temperature Circuit Low Input

  1. Disconnect the mass air flow meter connector.

  1. Connect terminals 4 (THA) and 5 (E2) of the mass air flow meter wire harness side connector.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

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

  1. Read the value displayed on the intelligent tester.

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


NG
Go to step 3
OK

CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW METER (HILUX_TGN26 RM000000VW602CX.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) - C76-29 (THA)
    		Always
    		Below 1 Ω
    C36-5 (E2) - C75-28 (E2)
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM (HILUX_TGN26 RM000000VW2023X.html)

4.READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)
Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.2Tr-Fe Engine Control.Sfi System (W/ Secondary Air Injection 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 intelligent tester on.

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

  1. Read the value displayed on the intelligent tester.

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


NG
Go to step 5
OK

REPLACE MASS AIR FLOW METER (HILUX_TGN26 RM000000VW602CX.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 C76-29 (THA) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (HILUX_TGN26 RM000000VW2023X.html)