System Overview

System overview

control module




The primary task of the combustion preheater module (CPM) is to manage the functions of:
- auxiliary heater
- parking heater
- remote start
The same control module is sued for both the auxiliary heater and the parking heater. The heater can serve as either an auxiliary heater or a parking heater depending on vehicle configuration. The auxiliary heater is standard for diesel engine vehicles in certain markets (cold climates). The heat generated by the diesel engine is not sufficient to maintain a comfortable temperature in the passenger compartment.
The heater is located in the front right wheel housing, up toward the A-pillar. It is covered by the plastic wheel arch liner.
The combustion preheater module (CPM) communicates with directly connected components and with other control modules via CAN communication.
The control module checks activations that are made, and the input and output signals through integrated diagnostics. A diagnostic trouble code is generated if the control module detects a fault. Any diagnostic trouble codes are stored in the control module memory. The information can be read off using the diagnostic tool.
A simple way to check that the combustion preheater module (CPM) is supplied with power is to activate the heater and listen to hear if it starts. It can be activated via:
- the control stalk (vehicles with parking heater)
- the diagnostic tool (vehicles with auxiliary heater)
- remote start device (accessory)

Signals
The table below summarizes input and output signals to and from the combustion preheater module (CPM). The illustration below displays the same information with the Volvo component designation.