DTC P0103 Mass Or Volume Air Flow Circuit High Input

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

DTC DETECTING CONDITION:

Immediately at fault recognition
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 repairing or replacing the defective part, perform the Clear Memory Mode < Ref. to OPERATION , Clear Memory Mode. > and Inspection Mode < Ref. to PROCEDURE , Inspection Mode. >.

WIRING DIAGRAM:

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

DIAGNOSIS PROCEDURE

Step	Check	Yes	No
1 CONNECT SUBARU SELECT MONITOR OR THE GENERAL SCAN TOOL, AND READ DATA. Turn the ignition switch to OFF. Connect the Subaru Select Monitor or general scan tool to data link connector. Turn the ignition switch to ON, and the Subaru Select Monitor or general scan tool power switch to ON. Start the engine. Read the voltage of mass air flow sensor using Subaru Select Monitor or general scan tool. NOTE: Subaru Select Monitor For detailed operation procedure, refer to "READ CURRENT DATA FOR ENGINE". < Ref. to SUBARU SELECT MONITOR . > General scan tool For detailed operation procedure, refer to the general scan tool operation 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 the 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 of 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 connectors from ECM. Measure the resistance of harness between ECM connector and mass air flow sensor connector. Connector & terminal (B3) No. 2 - (B135) No. 34:	Is the resistance less than 1 Ω?	Replace the mass air flow sensor. < Ref. to MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR . >	Repair the open circuit of harness between mass air flow sensor connector and ECM connector.