P0112

P0112, P0113 IAT SENSOR





Description





The intake air temperature sensor is built-into 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 temperature rise.





[Reference data]






CAUTION: Do not 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.





DTC Logic

DTC DETECTION LOGIC






DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
- GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 5 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES - Go to SEE Diagnosis Procedure.
NO - INSPECTION END




Diagnosis Procedure
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E9. Refer to Ground Inspection in Circuit Inspection.
Is the inspection result normal?
YES - GO TO 2.
NO - Repair or replace ground connection.
2.CHECK INTAKE AIR TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect mass air flow sensor (with intake air temperature sensor) harness connector.
2. Turn ignition switch ON.





3. Check the voltage between mass air flow sensor harness connector and ground.





Is the inspection result normal?
YES - GO TO 3.
NO - Repair open circuit or short to ground or short to power in 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 the continuity between mass air flow sensor harness connector and ECM harness connector.





4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES - GO TO 4.
NO - Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK INTAKE AIR TEMPERATURE SENSOR
SEE Component Inspection.
Is the inspection result normal?
YES - GO TO 5.
NO - Replace mass air flow sensor (with intake air temperature sensor). Service and Repair.
5.CHECK INTERMITTENT INCIDENT
Intermittent Incident.
- INSPECTION END




Component Inspection
1.CHECK INTAKE AIR TEMPERATURE SENSOR
1. Turn ignition switch OFF.
2. Disconnect mass air flow sensor harness connector.





3. Check resistance between mass air flow sensor terminals as follows.






Is the inspection result normal?
YES - INSPECTION END
NO - Replace mass air flow sensor (with intake air temperature sensor). Service and Repair.