DTC P0103 Mass Or Volume Air Flow Circuit High Input

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

DTC DETECTING CONDITION:

Detect as soon as the malfunction occurs.
GENERAL DESCRIPTION < Ref. to DTC P0103 MASS OR VOLUME AIR FLOW CIRCUIT HIGH INPUT , Diagnostic Trouble Code (DTC) Detecting Criteria>

TROUBLE SYMPTOM:

Erroneous idling
Engine stalls.
Poor driving performance

CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode < Ref. to , OPERATION , Clear Memory Mode.> and Inspection Mode < Ref. to , PROCEDURE , Inspection Mode. >

WIRING DIAGRAM:

Fig 1: Wiring Diagram - DTC P0103 Mass Or Volume Air Flow Circuit High Input

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE (DTC P0103)

Step	Check	Yes	No
1 READ THE DATA CONNECTING SUBARU SELECT MONITOR OR OBD-II GENERAL SCAN TOOL. Turn the ignition switch to OFF. Connect the Subaru Select Monitor to data link connector. Turn the ignition switch to ON, and the Subaru Select Monitor switch to ON. Start and idle the engine. Read the voltage of mass air flow sensor using Subaru Select Monitor or OBD-II general scan tool. NOTE: Subaru Select Monitor For detailed operation procedure, refer to the "READ CURRENT DATA SHOWN ON DISPLAY FOR ENGINE". < Ref. to , SUBARU SELECT MONITOR . > OBD-II general scan tool For detailed operation procedure, refer to the OBD-II general scan tool instruction manual .	Is the voltage 0.2 - 4.7 V?	Even if the malfunction indicator light illuminates, the circuit has returned to a normal condition at this time.	Go to step 2.
2 CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW SENSOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connector from mass airflow sensor. Turn the ignition switch to ON. Measure voltage between mass air flow sensor connector and chassis ground. Connector & terminal (B3) No. 3 (+) - Chassis ground (-):	Is the voltage more than 5 V?	Repair the battery short circuit in harness between mass air flow sensor connector and ECM connector.	Go to step 3.
3 CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW SENSOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connector from ECM. Measure the resistance of harness between ECM connector and mass air flow sensor connector. Connector & terminal (B3) No. 2 - (B136) No. 31:	Is the resistance less than 1 ?	Replace the mass air flow sensor. < Ref. to MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR . >	Repair the open circuit in harness between mass air flow sensor connector and ECM connector.