P0112

P0112, P0113 IAT Sensor

Component Description

The intake air temperature sensor is built-into the mass air flow sensor (1). The sensor detects intake air temperature and transmits a signal to the ECM.





The temperature sensing unit uses a thermistor which is sensitive to the change in temperature. Electrical resistance of the thermistor decreases in response to the rise in temperature.

[Reference data]









*: This data is reference value and is measured between ECM terminal 34 (Intake air temperature sensor) and ground.

CAUTION:

Never use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

On Board Diagnosis Logic






DTC Confirmation Procedure

1) If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next step.
a) Turn ignition switch OFF and wait at least 10 seconds.
b) Turn ignition switch ON.
c) Turn ignition switch OFF and wait at least 10 seconds.
2) Turn ignition switch ON and wait at least 5 seconds.
3) Check 1st trip DTC.
4) If 1st trip DTC is detected, go to "Diagnosis Procedure".

Diagnosis Procedure

1. CHECK GROUND CONNECTIONS

1 Turn ignition switch OFF.
2 Loosen and retighten three ground screws on the body. Refer to [Power Supply and Ground Circuit Check] Power Supply and Ground Circuit Check.






OK or NG
OK
GO TO 2.
NG
Repair or replace ground connections.

2. CHECK INTAKE AIR TEMPERATURE SENSOR POWER SUPPLY CIRCUIT

1 Disconnect mass air flow sensor (intake air temperature sensor is built-in) harness connector.





2 Turn ignition switch ON.
3 Check voltage between mass air flow sensor terminal 5 and ground.











OK or NG
OK
GO TO 3.
NG
Repair harness or connectors.

3. CHECK INTAKE AIR TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1 Turn ignition switch OFF.
2 Disconnect ECM harness connector.
3 Check harness continuity between mass air flow sensor terminal 6 and ECM terminal 67.
Refer to Wiring Diagram.






4 Also check harness for short to ground and short to power.

OK or NG
OK
GO TO 4.
NG
Repair open circuit or short to ground or short to power in harness or connectors.

4. CHECK INTAKE AIR TEMPERATURE SENSOR

Refer to "Component Inspection".

OK or NG
OK
GO TO 5.
NG
Replace mass air flow sensor (with intake air temperature sensor). Refer to [Air Cleaner and Air Duct: Exploded View] Exploded View.

5. CHECK INTERMITTENT INCIDENT

Refer to [Service Information for Electrical Incident: Intermittent Incident] Service Information for Electrical Incident: Intermittent Incident.


INSPECTION END

Component Inspection

Intake Air Temperature Sensor

1) Check resistance between mass air flow sensor (1) terminals 5 and 6 under the following conditions.











2) If NG, replace mass air flow sensor (with intake air temperature sensor).