System Overview

System overview

Control module




The primary task of the combustion preheater module (CPM) is to manage the functions for:
- engine coolant heater
- parking heater
- remote start, see Design and Function, accessory electronic module (AEM).
The electrical engine block heater is managed by the accessory electronic module (AEM) For more information, see Design and Function, accessory electronic module (AEM).
The same control module is used for both the engine coolant heater and the parking heater. Depending on the vehicle configuration, the heater can function as an engine coolant heater or as a parking heater. The engine coolant heater is standard on vehicles with diesel engines in some markets (cold climates). The heater, which uses radiant heat from the diesel engine, is not capable of maintaining a comfortable passenger compartment temperature.
The combustion preheater module (CPM) is positioned on the right-hand side of the engine compartment.
The combustion preheater module (CPM) communicates both with directly connected components and with other control modules via CAN communication.
The control module checks activations and input and output signals via an integrated diagnostic system. A diagnostic trouble code (DTC) is stored if the control module detects a fault. Any diagnostic trouble codes (DTCs) are stored in the control module memory. The data can be read off using VIDA.
A simple way to check that the combustion preheater module (CPM) is supplied with power is to activate the heater. Listen if the heater starts. It can be activated using:
- the control stalk on vehicles with a parking heater
- VIDA for vehicles with engine coolant heaters.
For further information, also see Signal specifications.

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