Combustion PREHEATER Module (CPM) (2008-2012): Design: Heater

Fig 1: Identifying Heater Components

Courtesy of VOLVO CARS CORPORATION

The heater has the following internal electrical components: 

• control module
• combustion air fan motor
• glow plug
• coolant temperature sensor
• overheating sensor
• fuel preheater (diesel only)

External electrical components: 

• Coolant pump
• fuel pump
• remote start device (accessory)

There are 6 connectors above the control module. 3 of these are accessible from outside and are for connection to the vehicle, coolant pump and fuel pump. The other 3 are under a plastic cover and are for internal electrical components. The fan motor is directly connected to the control module circuit board with 2 pins.