Checking The Power Supply And Ground For The Combustion PREHEATER Module (CPM)

Fig 1: Identifying Ignition OFF

Courtesy of VOLVO CARS OF NORTH AMERICA.

• Ignition off.

  Check that the following fuses are intact:

  • Main fuse by battery
  • The fuse for the combustion preheater module (CPM) in the engine compartment fusebox.

  Check the cable between the engine compartment fusebox and the combustion preheater module (CPM). Check for a short-circuit to supply voltage. Check for a short-circuit to ground. Check for an open-circuit.

  Check the cable between the ground terminal and the combustion preheater module (CPM). Check for an open-circuit. Check for a short-circuit to supply voltage.

  Check the ground terminal for the combustion preheater module (CPM). Check for contact resistance and oxidation.

  Other information 

  • see FUEL FIRED BOOSTER HEATER CONTROL UNIT (B5254T3, L. H. D; 2004-2007) and FUEL FIRED BOOSTER HEATER CONTROL UNIT (2004-09)
  • see CHECKING WIRING AND TERMINALS .
  Fig 2: Identifying Ohmmeter

  Courtesy of VOLVO CARS OF NORTH AMERICA.
  Fig 3: View Of Central Electronic Module (CEM)

  Courtesy of VOLVO CARS OF NORTH AMERICA.

Was a fault detected? 

• YES 

  Refer to VERIFICATION 

• NO 

  Refer to CHECKING THE COMMUNICATION WITH THE COMBUSTION PREHEATER MODULE (CPM)