DTC    P0112    Intake Air Temperature Circuit Low Input

DTC    P0113    Intake Air Temperature Circuit High Input


DESCRIPTION

A190753E05
  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. Fail-safe mode continues until a pass condition is detected.

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

Temperature Displayed
Malfunction
-40°C (-40°F)
Open circuit
Higher than 128°C (262°F)
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 circuit and stores a DTC.
Example:
If the sensor output voltage is more 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 less than 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


Related DTCs
P0112: Intake Air Temperature Sensor Range Check (Low Voltage)
P0113: Intake Air Temperature Sensor Range Check (High Voltage)
Required Sensors/Components (Main)
Intake air temperature sensor
Required Sensors/Components (Related)
-
Frequency of Operation
Continuous
Duration
0.5 seconds
MIL Operation
Immediate
Sequence of Operation
None

TYPICAL ENABLING CONDITIONS


Monitor runs whenever following DTCs not present
None
Battery voltage
8 V or more
Ignition switch
ON
Starter
OFF

TYPICAL MALFUNCTION THRESHOLDS


P0112 
Intake air temperature sensor voltage [Intake air temperature]
Less than 0.18 V [Higher than 128°C (262°F)]

P0113 
Intake air temperature sensor voltage [Intake air temperature]
More than 4.91 V [Below -55°C (-67°F)]

COMPONENT OPERATING RANGE


Intake air temperature sensor voltage [Intake air temperature]
0.18 to 4.91 V [-55 to 128°C (-67 to 262°F)]

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON and turn the Techstream on.
  3. Clear DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  4. Turn the ignition switch off and wait for at least 30 seconds.
  5. Turn the ignition switch to ON and turn the Techstream on.
  6. Wait 0.5 seconds or more.
  7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
  8. Read pending DTCs.

    HINT:
    1. If a pending DTC is output, the system is malfunctioning.
    2. If a pending DTC is not output, perform the following procedure.
  9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  10. Input the DTC: P0112 or P0113.
  11. Check the DTC judgment result.

    Techstream Display
    Description
    NORMAL
    1. DTC judgment completed
    2. System normal
    ABNORMAL
    1. DTC judgment completed
    2. System abnormal
    INCOMPLETE
    1. DTC judgment not completed
    2. Perform driving pattern after confirming DTC enabling conditions
    N/A
    1. Unable to perform DTC judgment
    2. Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:
    1. If the judgment result shows NORMAL, the system is normal.
    2. If the judgment result shows ABNORMAL, the system has a malfunction.
  12. If the judgment result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs (Click here).

    HINT:
    1. If a permanent DTC is output, the system is malfunctioning.
    2. If no permanent DTC is output, the system is normal.

WIRING DIAGRAM


A256689E05


INSPECTION PROCEDURE

HINT:
Read freeze frame data using the Techstream. 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.
1.READ VALUE USING TECHSTREAM (INTAKE AIR TEMPERATURE)
  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

  1. Read the value displayed on the Techstream.

    OK:
    Same as actual intake air temperature.
    Result 
    Result
    Proceed to
    -40°C (-40°F)
    A
    Higher than 128°C (262°F)
    B
    Same as actual intake air temperature
    C

    HINT:
    1. If there is an open circuit, the Techstream indicates -40°C (-40°F).
    2. If there is a short circuit, the Techstream indicates higher than 128°C (262°F).


B
Go to step 4

C
CHECK FOR INTERMITTENT PROBLEMS (Click here)
A


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


    A195056E04
  1. Disconnect the mass air flow meter connector.

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

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

  1. Read the value displayed on the Techstream.

    Standard value:
    Higher than 128°C (262°F)
    Text in Illustration 
    *1
    Mass Air Flow Meter
    *2
    ECM
    *a
    Front view of wire harness connector
    (to Mass Air Flow Meter)

    HINT:
    Perform "Inspection After Repair" after replacing the mass air flow meter (Click here).


NG
Go to step 3
OK

REPLACE MASS AIR FLOW METER (Click here)  

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
    C63-4 (THA) - C51-90 (THA)
    Always
    Below 1 Ω
    C63-5 (E2) - C51-122 (ETHA)
    Always
    Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (Click here)  

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


    A186168E05
  1. Disconnect the mass air flow meter connector.

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

  1. Read the value displayed on the Techstream.

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

    HINT:
    Perform "Inspection After Repair" after replacing the mass air flow meter (Click here).


NG
Go to step 5
OK

REPLACE MASS AIR FLOW METER (Click here)  

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
    C63-4 (THA) or C51-90 (THA) - Body ground
    Always
    10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (Click here)