Body Integrated Unit Power Supply And Ground Circuit

NOTE: For the DC power supply circuit, refer to "WIRING DIAGRAMS". Ref. to WIRING SYSTEM (CROSSTREK MODEL)>POWER SUPPLY CIRCUIT .

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.