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Body Integrated Unit Power Supply And Ground Circuit

NOTE: For the DC power supply circuit, refer to "WIRING DIAGRAMS". < Ref. to appropriate wiring diagram in SYSTEM WIRING DIAGRAM article. >

Fig 1: DC Power Supply - Circuit Diagram

G10274673

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK DTC OF BODY INTEGRATED UNIT. Check DTC of body integrated unit. < Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) . >	Is the DTC of power line displayed on body integrated unit?	Repair or replace it according to the DTC.	Go to step 2 .
2 CHECK CURRENT DATA. Check the current data «BATT voltage (control) » display of body integrated unit. < Ref. to OPERATION , Read Current Data. >	Is the display 10 - 15 V?	Go to step 4 .	Go to step 3 .
3 CHECK HARNESS BETWEEN BODY INTEGRATED UNIT AND BATTERY. Turn the ignition switch to ON. Measure the voltage between body integrated unit and chassis ground. Connector & terminal (B280) No. 4 (+) - Chassis ground (-): (B280) No. 7 (+) - Chassis ground (-): (B281) No. 32 (+) - Chassis ground (-):	Is the voltage 9 - 16 V?	Go to step 4 .	Check harness for open circuit between the body integrated unit and the battery or a blown fuse.
4 CHECK BODY INTEGRATED UNIT IGN POWER SUPPLY CIRCUIT. Turn the ignition switch to ON. Measure the voltage between F/B fuse No. 5 and chassis ground. Connector & terminal F/B fuse No. 5 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 5 .	Repair the open circuit of the harness between body integrated unit and ignition switch.
5 CHECK BODY INTEGRATED UNIT AND ACC VOLTAGE SUPPLY CIRCUIT. Turn the ignition switch to ACC. Measure the voltage between F/B fuse No. 9 and chassis ground. Connector & terminal F/B fuse No. 9 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 6 .	Repair the open circuit of the harness between body integrated unit and ignition switch.
6 CHECK HARNESS BETWEEN BODY INTEGRATED UNIT AND CHASSIS GROUND. Turn the ignition switch to OFF. Measure the harness resistance between the body integrated unit and chassis ground. Connector & terminal (i84) No. 4 - Chassis ground: (B280) No. 2 - Chassis ground:	Is the resistance less than 1 Ω?	Go to step 7 .	Repair the open circuit of harness between the body integrated unit and chassis ground.
7 CHECK FOR POOR CONTACT.	Is there poor contact of connector?	Repair the poor contact.	End.