Combustion PREHEATER Module (CPM)
WARNING: This page is about a different car, the 2010 Volvo V70, 2009 Volvo V70, and 2008 Volvo V70. However, it is still accessible from the selected car via links, so may be relevant.
The control module is integrated in the heater - located under a cover at one end of the heater. The connection for the combustion air fan is located on the underside of the control module.
The control module receives signals from the sensor and other components. The control module uses this data to regulate heater start, output, shut-off, etc.
The control module also continually monitors heater components to ensure proper function.