ENGINE (DIAGNOSTICS)(H4DOTC DIESEL) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC P0112 INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT LOW

DTC DETECTING CONDITION:

Immediately at fault recognition

TROUBLE SYMPTOM:

• Improper idling

• Poor driving performance

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode and Inspection Mode .

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK CURRENT DATA.

1) Start the engine.

2) Read the data of intake air temperature sensor signal using Subaru Select Monitor or general scan tool.

NOTE:

• Subaru Select Monitor

For detailed operation procedures, refer to “READ CURRENT DATA FOR ENGINE”.

• General scan tool

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

Is the intake air temperature 120°C (248°F) ?

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 may be the cause.

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

1) Turn the ignition switch to OFF.

2) Disconnect the connectors from ECM and mass air flow and intake air temperature sensor.

3) Measure the resistance between ECM connector and chassis ground.

Connector & terminal

(B134) No. 53 — Chassis ground:

Is the resistance 1 MΩ or more?

Replace the 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.