DTC    P0112    Intake Air Temperature Circuit Low Input

DTC    P0113    Intake Air Temperature Circuit High Input

for Preparation Click here


DESCRIPTION

The intake air temperature sensor is built into the Mass Air Flow (MAF) meter and senses the intake air temperature.
A thermistor built into the sensor changes its resistance value according to the intake air temperature.
The lower the intake air temperature, the greater the thermistor resistance value. The higher the intake air temperature, the lower the thermistor resistance value (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. 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 potential at terminal THA also changes. Based on this signal, the ECM increases the fuel injection volume to improve drivability with a cold engine.
A067628E13

HINT:
When the intake air temperature sensor output is outside the normal range, the ECM determines that this is a malfunction.


P0112 
DTC Detection Drive Pattern
DTC Detection Condition
Trouble Area
Engine idles for approximately 15 seconds
Intake air temperature sensor output is more than 140°C (284°F).
(2 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 
DTC Detection Drive Pattern
DTC Detection Condition
Trouble Area
Engine idles for approximately 15 seconds
Intake air temperature sensor output is less than -40°C (-40°F).
(2 trip detection logic)
  1. Open in intake air temperature sensor circuit
  2. Intake air temperature sensor (built into mass air flow meter)
  3. ECM

Related Data List 
DTC No.
Data List
P0112
  1. Intake Air
P0113

HINT:
  1. If DTC P0112 or P0113 is stored, the following symptoms may appear:
    1. Misfire
    2. Combustion noise
    3. Black smoke
    4. White smoke
    5. Lack of power
  2. When DTC P0112 or P0113 is stored, check the intake air temperature by entering the following menus on 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


A199002E01


INSPECTION PROCEDURE

NOTICE:
  1. When replacing the ECM, the ECM needs Registration and Initialization (Click here).

HINT:
  1. When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the intelligent tester. Then after installing the new ECM, perform all of the initializations/registrations for the "Learning Values Write" function by following the instructions shown on the tester display.
  2. 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, 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 and turn the tester on.

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

  1. Read the value.

    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).
    2. If there is a short circuit, the intelligent tester indicates 140°C (284°F) or higher.



B
Go to step 4

C
Go to step 11
A


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


    A199019E01

  1. Disconnect the mass air flow meter connector.

  1. Connect terminals THA and 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 and turn the tester on.

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

  1. Read the value.

    Standard:
    140°C (284°F) or higher

    Text in Illustration 
    *1
    		Mass Air Flow Meter
    *2
    		Front view of wire harness connector
    (to Mass Air Flow Meter)

  1. Reconnect the mass air flow meter connector.



OK
Go to step 7

NG
Go to step 3

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

  1. Disconnect the mass air flow meter connector.



    A199020E01

  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
    A37-4 - A19-30 (THA)
    		Always
    		Below 1 Ω
    A37-5 - A19-31 (ETHA)
    		Always
    		Below 1 Ω

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to MASS Air Flow Meter)
    *2
    		Front view of wire harness connector
    (to ECM)

  1. Reconnect the mass air flow meter connector.

  1. Reconnect the ECM connector.



OK
Go to step 9

NG
Go to step 8

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

  1. Disconnect the mass air flow meter connector.



    A200307E01

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

  1. Reconnect the mass air flow meter connector.

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

  1. Read the value.

    Standard:
    -40°C (-40°F)

    Text in Illustration 
    *1
    		Mass Air Flow Meter

  1. Reconnect the mass air flow meter connector.



OK
Go to step 10

NG
Go to step 5

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

  1. Disconnect the mass air flow meter connector.



    A199020E02

  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
    A37-4 or A19-30 (THA) - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Mass Air Flow Meter)
    *2
    		Front view of wire harness connector
    (to ECM)

  1. Reconnect the mass air flow meter connector.

  1. Reconnect the ECM connector.



NG
Go to step 8
OK


6.REPLACE ECM

  1. Replace the ECM (Click here).



NEXT
Go to step 11

7.CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW METER

  1. Replace the mass air flow meter (Click here).



NEXT
Go to step 11

8.REPAIR OR REPLACE HARNESS OR CONNECTOR


NEXT
Go to step 11

9.CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM

  1. Replace the ECM (Click here).



NEXT
Go to step 11

10.REPLACE MASS AIR FLOW METER

  1. Replace the mass air flow meter (Click here).


NEXT


11.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

  1. Connect the intelligent tester to the DLC3.

  1. Clear the DTCs (Click here).

  1. Start the engine.

  1. Allow the engine to idle for 15 seconds or more.

  1. Enter the following menus: Powertrain / Engine and ECT / DTC.

  1. Confirm that the DTC is not output again.


NEXT

END