Control Module Power Supply And Ground Line

CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode < Ref. to OPERATION , CLEAR MEMORY MODE > and INSPECTION MODE < Ref. to OPERATION , INSPECTION MODE. >

WIRING DIAGRAM:

Fig 1: Control Module Power Supply And Ground Line Wiring Diagram
Courtesy of SUBARU OF AMERICA, INC.

CONTROL MODULE POWER SUPPLY AND GROUND LINE DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK MAIN RELAY. Turn the ignition switch to OFF. Remove the main relay. Connect the battery to main relay terminals No. 1 and No. 2. Measure the resistance between main relay terminals. Terminals No. 3 - No. 5: No. 4 - No. 6:	Is the measured value less than 10 Ω?	Go to step 2.	Replace the main relay.
2 CHECK GROUND CIRCUIT OF ECM. Disconnect the connector from ECM. Measure the resistance of harness between ECM and chassis ground. Connector & terminal (B134) No. 6 - Chassis ground: (B134) No. 7 - Chassis ground: (B134) No. 34 - Chassis ground: (B135) No. 1 - Chassis ground: (B135) No. 4 - Chassis ground: (B137) No. 1 - Chassis ground: (B137) No. 2 - Chassis ground:	Is the measured value less than 5 Ω?	Go to step 3.	Repair the open circuit in harness between ECM connector and engine grounding terminal.
3 CHECK INPUT VOLTAGE OF ECM. Measure the voltage between ECM connector and chassis ground. Connector & terminal (B135) No. 19 (+) - Chassis ground (-): (B137) No. 15 (+) - Chassis ground (-):	Is the measured value more than 10 V?	Go to step 4.	Repair the open or ground short circuit of power supply circuit.
4 CHECK INPUT VOLTAGE OF MAIN RELAY. Measure the voltage between main relay connector and chassis ground. Connector & terminal (B47) No. 1 (+) - Chassis ground (-): (B47) No. 5 (+) - Chassis ground (-): (B47) No. 6 (+) - Chassis ground (-):	Is the measured value more than 10 V?	Go to step 5.	Repair the open or ground short circuit in harness of power supply circuit.
5 CHECK INPUT VOLTAGE OF ECM. Connect the main relay connector. Turn the ignition switch to ON. Measure the voltage between ECM connector and chassis ground. Connector & terminal (B135) No. 5 (+) - Chassis ground (-): (B135) No. 6 (+) - Chassis ground (-): (B137) No. 17(+) - Chassis ground (-):	Is the measured value more than 10 V?	Check the ignition control system. < Ref. to IGNITION CONTROL SYSTEM , Diagnostics for Engine Starting Failure. >	Repair the open or ground short circuit in harness between ECM connector and main relay connector.