April 5, 2026: LEMON Manuals is launched! Read the announcement.

Body Integrated Unit Power Supply And Ground Circuit

NOTE: For the DC power supply circuit, refer to "WIRING DIAGRAMS". Refer to WIRING SYSTEM>POWER SUPPLY CIRCUIT .

G12448278

Courtesy of SUBARU OF AMERICA, INC.

CHECK DTC OF BODY INTEGRATED UNIT.
Check DTC of body integrated unit.

Refer to BODY CONTROL SYSTEM (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

Is the DTC of power line displayed on body integrated unit?

Yes: Repair or replace it according to the DTC.

No: Go to 2.
CHECK HARNESS BETWEEN BODY INTEGRATED UNIT AND BATTERY.
1. Turn the ignition switch to ON.
2. Measure the voltage between body integrated unit and chassis ground.
  Connector & terminal
  
  (B281) No. 3 (+) - Chassis ground (-):
  
  (B280) No. 32 (+) - Chassis ground (-):
  
  (B281) No. 6 (+) - Chassis ground (-):
  
  (B281) No. 7 (+) - Chassis ground (-):
  
  (i84) No. 6 (+) - Chassis ground (-):
  
  Is the voltage 9 - 16 V?
  
  Yes: Go to 3.
  
  No: Check harness for open circuit between the body integrated unit and the battery or a blown fuse.
CHECK HARNESS BETWEEN BODY INTEGRATED UNIT AND CHASSIS GROUND.
1. Turn the ignition switch to OFF.
2. Measure the harness resistance between the body integrated unit and chassis ground.
  Connector & terminal
  
  (B280) No. 1 - Chassis ground:
  
  (i84) No. 1 - Chassis ground:
  
  Is the resistance less than 1 Ω?
  
  Yes: Go to 4.
  
  No: Repair the open circuit of harness between the body integrated unit and chassis ground.
CHECK FOR POOR CONTACT.
Is there poor contact of connector?

Yes: Repair the poor contact.

No: Check body integrated unit.