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

WARNING: This page is about a different variant/trim than selected.

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DTC detecting condition:

Immediately at fault recognition

Trouble symptom:
- Improper idling
- Poor driving performance
Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM (IMPREZA MODEL)>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD .

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

CHECK DATA MONITOR .
1. Start the engine.
2. Using the Subaru Select Monitor or a general scan tool, read the value of [Intake Air Temp.].
  NOTE:
  - Subaru Select Monitor For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON (DIAG)>DATA MONITOR .
  - General scan tool For detailed operation procedures, refer to the general scan tool operation manual.
  Is the value of [Intake Air Temp.] 120°C (248°F) or more?
  
  Yes: Go to 2.
  
  No: 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.
CHECK HARNESS BETWEEN ECM AND THE MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR (SHORT TO GROUND) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connectors from the mass air flow and intake air temperature sensor.
4. Measure the resistance between ECM connector and chassis ground.
  Connector and terminal
  
  (B134) No. 43 - Chassis ground:
  
  Is the resistance 1 MΩ or more?
  
  Yes: Replace the mass air flow and intake air temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO (EXCEPT FOR HEV))>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR .
  
  No: Repair the ground short circuit of harness between ECM connector and the mass air flow and intake air temperature sensor connector.