GSIC - Global Service Information Center

### 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

The Intake Air Temperature (IAT) sensor, mounted on the air cleaner hose, monitors the IAT.
The IAT sensor has a 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 decreases. The variations in resistance are communicated to the ECM as changes in voltage (see Fig. 1).
The IAT sensor is connected to the ECM (see below). The 5 V power source voltage in the ECM is applied to the IAT sensor from terminal THA via resistor R.
The resistor R and the IAT sensor are connected in series. When the resistance value of the IAT sensor changes in accordance with changes in the IAT, the voltage at terminal THA also changes. Based on this signal, the ECM increases the fuel injection volume to improve the driveability during cold engine operation.

DTC No. | DTC Detection Condition | Trouble Area

P0110/24

Open or short in IAT sensor circuit for 0.5 seconds (1 trip detection logic)

1. Open or short in IAT sensor circuit
2. IAT sensor
3. ECM

P0112/24

Short in IAT sensor circuit for 0.5 seconds (1 trip detection logic)

1. Open or short in IAT sensor circuit
2. IAT sensor
3. ECM

P0113/24

Open in IAT sensor circuit for 0.5 seconds (1 trip detection logic)

1. Open or short in IAT sensor circuit
2. IAT sensor
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 / Data List / Intake Air.

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

## WIRING DIAGRAM

## 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 a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, and other data from the time the malfunction occurred.

NOTICE:

  If the ECM is replaced, the new ECM needs initialization (Click here).

## When using intelligent tester:

1.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 / Data List / Intake Air.

1. Read the values.

   OK:
     Same value as the actual air temperature.

   Result:

     Temperature Displayed | Proceed to
     -40°C (-40°F) | A
     140°C (284°F) or more | B
     OK (same as air temperature near to intake manifold) | 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 4

| C |

CHECK FOR INTERMITTENT PROBLEMS

A |

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

1. Disconnect the I3 IAT sensor connector.

1. Connect terminals 1 and 2 of the IAT sensor wire harness side connector.

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 / Data List / Intake Air.

1. Read the values.

   OK:
     140°C (284°F) or more

| OK |

CONFIRM GOOD CONNECTION AT SENSOR. IF OK, REPLACE INTAKE AIR TEMPERATURE SENSOR

NG |

3.READ DATA LIST (CHECK FOR OPEN IN ECM)

1. Disconnect the I3 IAT sensor connector.

1. Connect terminals THA and E2 of the E8 ECM connector.

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

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 / Data List / Intake Air.

1. Read the values.

   OK:
     140°C (284°F) or more

| OK |

REPAIR OR REPLACE HARNESS AND CONNECTOR

NG |

CONFIRM GOOD CONNECTION AT ECM. IF OK, REPLACE ECM

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

1. Disconnect the I3 IAT sensor.

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 / Data List / Intake Air.

1. Read the values.

   OK:
     -40°C (-40°F)

| OK |

REPLACE INTAKE AIR TEMPERATURE SENSOR

NG |

5.READ DATA LIST (CHECK FOR SHORT IN ECM)

1. Disconnect the I3 IAT sensor.

1. Disconnect the E8 ECM connector.

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 / Data List / Intake Air.

1. Read the values.

   OK:
     -40°C (-40°F)

| OK |

REPAIR OR REPLACE HARNESS AND CONNECTOR

NG |

REPLACE ECM

## When not using intelligent tester:

1.CHECK ECM (THA VOLTAGE)

1. Start the engine.

1. Measure the voltage of the ECM connector.

   Standard voltage:

     Tester Connection | Condition | Specified Condition
     E8-31 (THA) - E8-28 (E2) | Idling, IAT at 20°C (68°F) | 0.5 to 3.4 V

| OK |

CHECK FOR INTERMITTENT PROBLEMS

NG |

2.INSPECT INTAKE AIR TEMPERATURE SENSOR

1. Remove the sensor.

1. Measure the resistance of the sensor.

   Standard resistance:

     Tester Connection | Condition | Specified Condition
     1 - 2 | 20°C (68°F) | 2.21 to 2.65 kΩ

   NOTICE:
     When checking that IAT sensor in water, keep the terminals dry. After the check, wipe the sensor dry.

| NG |

REPLACE INTAKE AIR TEMPERATURE SENSOR

OK |

3.CHECK WIRE HARNESS (ECM- INTAKE AIR TEMPERATURE SENSOR)

1. Disconnect the E8 ECM connector.

1. Disconnect the I3 sensor connector.

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

   Standard resistance:

     Tester Connection | Specified Condition
     E8-31 (THA) - I3-2 (THA) | Below 1 Ω
     E8-28 (E2) - I3-1 (E2) | Below 1 Ω
     E8-31 (THA) or I3-2 (THA) - Body ground | 10 kΩ or higher
     E8-28 (E2) or I3-1 (E2) - Body ground | 10 kΩ or higher

| NG |

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK |

REPLACE ECM