Body Integrated Unit Power Supply And Ground Circuit

NOTE: For the DC power supply circuit, refer to "WIRING DIAGRAMS". Ref. to WIRING SYSTEM>Power Supply Circuit .

Fig 1: Body Integrated Unit Power Supply And Ground - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

CHECK DTC OF BODY INTEGRATED UNIT .
Check DTC of body integrated unit. Ref. to BODY CONTROL(DIAGNOSTICS)>Diagnostic Trouble Code (DTC)>OPERATION .

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 CURRENT DATA .
Check the current data «BATT voltage (control)» display of body integrated unit. Ref. to BODY CONTROL(DIAGNOSTICS)>Data Monitor>OPERATION .

Is the display 10 - 15 V?
- Yes : Go to 4.
- No : Go to 3 .
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
  
  (B280) No. 1 (+) - Chassis ground (-):
  
  (B281) No. 7 (+) - Chassis ground (-):
  
  (B287) No. 4 (+) - Chassis ground (-):
  
  Is the voltage 9 - 16 V?
  - Yes : Go to 4 .
  - No : Check harness for open circuit between the body integrated unit and the battery or a blown fuse.
CHECK BODY INTEGRATED UNIT IGN POWER SUPPLY CIRCUIT .
1. Turn the ignition switch to ON.
2. Measure the voltage between F/B fuse No. 5 and chassis ground.
  Connector & terminal
  
  F/B fuse No. 5 (+) - Chassis ground (-):
  
  Is the display 10 V or more?
  - Yes : Go to 5 .
  - No : Repair the open circuit of the harness between body integrated unit and ignition switch.
CHECK BODY INTEGRATED UNIT AND ACC VOLTAGE SUPPLY CIRCUIT .
1. Turn the ignition switch to ACC.
2. Measure the voltage between F/B fuse No. 9 and chassis ground.
  Connector & terminal
  
  F/B fuse No. 9 (+) - Chassis ground (-):
  
  Is the display 10 V or more?
  - Yes : Go to 6 .
  - No : Repair the open circuit of the harness between body integrated unit and ignition switch.
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
  
  (i84) No. 4 - Chassis ground:
  
  (B287) No. 1 - Chassis ground:
  
  Is the resistance less than 1 Ω?
  - Yes : Go to 7 .
  - 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 : End.