DTC    P0110/24    Intake Air Temperature Circuit

DTC    P0112/24    Intake Air Temperature Circuit Low Input

DTC    P0113/24    Intake Air Temperature Circuit High Input

for Preparation Click here


DESCRIPTION


  1. A056276E07
  2. The Intake Air Temperature (IAT) sensor is built into the mass air flow (MAF) meter, and monitors the intake air temperature. The IAT sensor has a built-in thermistor that varies its resistance depending on the temperature of the intake air. When the air temperature is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. The variations in resistance are communicated to the ECM as changes in voltage (see figure 1).
  3. The IAT sensor is connected to the ECM. The 5 V power source voltage in the ECM is applied to the IAT sensor from terminal THA via resistor R.
  4. Resistor R and IAT sensor are connected in series. When the resistance value of the IAT sensor changes in accordance with changes in the intake air temperature, the voltage at terminal THA also changes. Based on this signal, the ECM increases the fuel injection volume to improve driveability during cold engine operation.

DTC No.
DTC Detection Condition
Trouble Area
P0110/24
Open or short in intake air temperature sensor circuit for 0.5 seconds
  1. Open or short in IAT sensor circuit
  2. IAT sensor (built into MAF meter)
  3. ECM
P0112/24
Short in intake air temperature sensor circuit for 0.5 seconds
  1. Short in IAT sensor circuit
  2. IAT sensor (built into MAF meter)
  3. ECM
P0113/24
Open in intake air temperature sensor circuit for 0.5 seconds
  1. Open in IAT sensor circuit
  2. IAT sensor (built into MAF meter)
  3. ECM

HINT:
When DTC P0110/24, P0112/24 or P0113/24 is detected, 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) or more
Short circuit


MONITOR DESCRIPTION

The ECM monitors the sensor voltage and uses this value to calculate the IAT. When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the IAT sensor and sets a DTC.
Example:
When the sensor voltage output is -40°C (-40°F) (P0113/24) or more than 140°C (284°F) (P0112/24) and if either condition continues for 0.5 seconds or more.
This monitor runs for 0.5 seconds after the ignition switch is turned ON (1 trip detection logic).

WIRING DIAGRAM


A098514E01


INSPECTION PROCEDURE

HINT:
  1. If DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
  2. Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions 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.


When using intelligent tester:

1.READ OUTPUT DTC

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON and turn the intelligent tester ON.

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

  1. Read DTCs.

Result:
Display (DTC Output)
Proceed to
P0110/24
A
P0112/24
B
P0113/24
C



B
Go to step 5

C
Go to step 3
A


2.READ DATA LIST (INTAKE AIR TEMPERATURE)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON and turn the intelligent tester ON.

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

  1. Read the value.

    OK:
    Temperature value is same as the actual intake air temperature.

    Result:
    Temperature Displayed
    		Proceed to
    -40°C (-40°F)
    		A
    140°C (284°F) or more
    		B
    OK (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 more.



B
Go to step 5

C
CHECK FOR INTERMITTENT PROBLEMS
A


3.READ DATA LIST (CHECK FOR OPEN IN WIRE HARNESS)
A098511E01

  1. Disconnect the A4 MAF meter connector.

  1. Connect terminals THA and E2 of the A4 MAF meter wire harness side connector.

  1. Turn the ignition switch ON and turn the intelligent tester ON.

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

  1. Read the value.

    OK:
    Temperature value is 140°C (284°F) or more



OK
CONFIRM GOOD CONNECTION AT SENSOR. IF OK, REPLACE MASS AIR FLOW METER
NG


4.READ DATA LIST (CHECK FOR OPEN IN ECM)
G039231E01

  1. Disconnect the A4 MAF meter connector.

  1. Connect terminals THA and E2 of the E11 and E12 ECM connectors.

    HINT:
    Before checking, perform a visual and contact pressure check on the ECM connector.

  1. Turn the ignition switch ON and turn the intelligent tester ON.

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

  1. Read the value.

    OK:
    Temperature value is 140°C (284°F) or more



OK
REPAIR OR REPLACE HARNESS AND CONNECTOR
NG

CONFIRM GOOD CONNECTION AT ECM. IF OK, REPLACE ECM 

5.READ DATA LIST (CHECK FOR SHORT IN WIRE HARNESS)
A096475E01

  1. Disconnect the A4 MAF meter connector.

  1. Turn the ignition switch ON and turn the intelligent tester ON.

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

  1. Read the value.

    OK:
    Temperature value is -40°C (-40°F)



OK
REPLACE MASS AIR FLOW METER
NG


6.READ DATA LIST (CHECK FOR SHORT IN ECM)
G039257E01

  1. Disconnect the E11 ECM connector.

  1. Turn the ignition switch ON and turn the intelligent tester ON.

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

  1. Read the value.

    OK:
    Temperature value is -40°C (-40°F)



OK
REPAIR OR REPLACE HARNESS AND CONNECTOR
NG

REPLACE ECM 


When not using intelligent tester:

1.CHECK ECM (THA VOLTAGE)
A066060E15

  1. Turn the ignition switch ON.

  1. Measure the voltage between terminals THA and E2 of the ECM connectors.

    Voltage:
    Intake Air Temperature
    		Specified Condition
    20°C (68°F)
    		0.5 to 3.4 V
    60°C (140°F)
    		0.2 to 1.0 V



OK
CHECK FOR INTERMITTENT PROBLEMS
NG


2.INSPECT INTAKE AIR TEMPERATURE SENSOR (MASS AIR FLOW METER)
Click here


NG
REPLACE MASS AIR FLOW METER
OK


3.CHECK WIRE HARNESS (ECM - MAF METER)
G034687E01

  1. Disconnect the E11 and E12 ECM connectors.

  1. Disconnect the A4 MAF meter connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    E11-29 (THA) - A4-4 (THA)
    		Below 1 Ω
    E12-28 (E2) - A4-5 (E2)
    		Below 1 Ω
    E11-29 (THA) or A4-4 (THA) - Body ground
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE ECM