DTC P0112 Intake Air Temperature Sensor 1 Circuit Low Bank 1: Notes

DTC DETECTING CONDITION:

Immediately at fault recognition

TROUBLE SYMPTOM:

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode <Ref. to OPERATION , Clear Memory Mode.>, and Inspection Mode <Ref. to PROCEDURE , Inspection Mode.>.
Use the check board when measuring the ECM terminal voltage and resistance.

WIRING DIAGRAM:

Engine Electrical System <Ref. to WIRING DIAGRAM , Engine Electrical System.>

Fig 1: Mass Or Volume Air Flow Sensor "A" - Wiring Diagram (Low)

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK CURRENT DATA. Start the engine. Read the value of «IAT Sensor #11» using the Subaru Select Monitor or a general scan tool. NOTE: Subaru Select Monitor For detailed operation procedures, refer to "Current Data Display For Engine". <Ref. to Subaru Select Monitor .> General scan tool For detailed operation procedures, refer to the general scan tool operation manual.	Is the value in «IAT Sensor #11» 120°C (248°F) or more?	Go to step 2 .	Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again. NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
2 CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connector from ECM. Disconnect the connectors from the mass air flow and intake air temperature sensor. Measure the resistance between the ECM connector and engine ground. Connector & terminal (E158) No. 5 - Engine ground:	Is the resistance 1 MΩ or more?	Replace the mass air flow and intake air temperature sensor. <Ref. to Mass Air Flow and Intake Air Temperature Sensor .>	Repair the ground short circuit of harness between ECM connector and the mass air flow and intake air temperature sensor connector.

Step

Check

Yes

1 CHECK CURRENT DATA.

Start the engine.
Read the value of «IAT Sensor #11» using the Subaru Select Monitor or a general scan tool.

NOTE:

For detailed operation procedures, refer to "Current Data Display For Engine". <Ref. to Subaru Select Monitor .>

For detailed operation procedures, refer to the general scan tool operation manual.

Is the value in «IAT Sensor #11» 120°C (248°F) or more?

Go to step 2 .

Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.

2 CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR.

Turn the ignition switch to OFF.
Disconnect the connector from ECM.
Disconnect the connectors from the mass air flow and intake air temperature sensor.
Measure the resistance between the ECM connector and engine ground.
Connector & terminal

(E158) No. 5 - Engine ground:

Is the resistance 1 MΩ or more?

Replace the mass air flow and intake air temperature sensor. <Ref. to Mass Air Flow and Intake Air Temperature Sensor .>

Repair the ground short circuit of harness between ECM connector and the mass air flow and intake air temperature sensor connector.