Checking The Power Supply And Ground For The Brake Control Module (BCM)

Fig 1: Identifying Ignition ON

Courtesy of VOLVO CARS OF NORTH AMERICA.

• Ignition on.

  Check the fuses in the fusebox in the engine compartment (30-supply) for the brake control module (BCM).

  NOTE: If any fuses are blown, check the circuit after the fuse for a short-circuit to ground before replacing the fuse. Then replace the fuse.

  Check the fuse in the central electronic module (CEM) (15-supply) for the brake control module (BCM).

  If the fuse is blown, check the cable between the brake control module (BCM) and the fuse. Check for a short-circuit to ground.

  If the fuse is intact, check the cable between the brake control module (BCM) and the fuse. Check for an open-circuit.

  Check the ground lead between the control module and the ground terminal. Check for an open-circuit. Also check the ground terminal. Check for contact resistance and oxidation.

  Remedy as necessary.

  Other information 

  • see CONNECTING THE BREAKOUT BOX
  • see SIGNAL DESCRIPTION WITH ABS/STC
  • see SIGNAL DESCRIPTION WITH DSTC
  • see CHECKING WIRING AND TERMINALS
  Fig 2: Breakout Box

  Courtesy of VOLVO CARS OF NORTH AMERICA.
  Fig 3: Identifying Ohmmeter

  Courtesy of VOLVO CARS OF NORTH AMERICA.
  Fig 4: Identifying Brake Control Module (BCM)

  Courtesy of VOLVO CARS OF NORTH AMERICA.

Was a fault detected? 

• YES 

  Refer to VERIFICATION 

• NO 

  Refer to CHECKING COMMUNICATION WITH THE BRAKE CONTROL MODULE (BCM)