Control Modules In The Control Area Network (Can)

Fig 1: Identifying Controller Area Network Components

Courtesy of VOLVO CARS CORPORATION

The number of control modules in the CAN network varies depending on the car model, equipment level and structure week, The structure week and construction week are not necessarily the same week. The construction week is the week in which the vehicle is built in the factory. The content of the vehicle is steered towards structure week. A structure week may extend over a number of construction weeks. Structure weeks are specified in the format YYYYWW.

For example, structure week 199815 indicates that the structure week of the vehicle is week 15, year 1998.

NOTE:

To troubleshoot respective CAN-net, see troubleshooting for CAN-related diagnostic trouble codes for Central electronic module (CEM). For example, choose any of CEM-DF01 - DF17 depending on CAN-net.

Explanation
LS CAN	=	CAN Low Speed Section (125 kbit/s)
HS CAN	=	CAN High Speed Section (500 kbit/s)
Serial	=	Serial communication (Volcano Lite) between the slave control module and the CAN control module (10.4 kbit/s). LIN (9.6 kbit/s).
Slave control module	=	A control module with low computing power which is connected to a main "control module" and which only operates on commands from the main control module.
Option	=	Accessories installed at the factory to order, when purchasing a new car.
Accessories	=	Aftermarket installation.

Control module	Name/ Function	Network	Miscellaneous
AEM	Accessory electronic module (AEM) Controls certain accessory functions for the vehicle, This control module communicates with other control modules via the low speed side of the network.	LS CAN	Accessories
Audio control module	Audio module (AUM) Controls the radio / audio equipment and communicates with the other modules via the network low speed sector.	LS CAN	Standard/ accessory/option.
Brake control module	Brake control module (BCM) Controls the ABS/EBD/DSTC/STC functions of the brake system and communicates with the other modules via the network high speed sector. Contains a terminating resistor for the network.	HS CAN
Climate control module	Climate control module (CCM) Controls the climate control system functions and communicates with the other modules via the network low speed sector.	LS CAN	STD/ MCC/ ECC
Central electronic module	Central electronic module (CEM) This is the network's main control module and the interface between the high and low speed sides. The control module has a comprehensive function in the electrical system and handles a large number of functions.	HS CAN/LS CAN
DDM	Driver door module (DDM) Controls the drivers door functions and communicates with the other modules via the network low speed side.	LS CAN
DEM	Differential electronic module (DEM) Controls four wheel drive engagement and communicates with the other modules via the network high speed side.	HS CAN	Option.
Driver information module	Driver information module (DIM) Controls the combined instrument panel functions and communicates with the other modules via the network low speed side.	LS CAN
ECM	Engine control module (ECM) Controls the engine's functions and communicates with other control modules via the high speed side of the network. Contains a terminating resistor for the high speed side of the network.	HS CAN	Different versions depending on the engine alternative.
ICM	Infotainment control module (ICM) Controls the radio, navigation and telephone functions. This is the primary unit for communication with the units in the MOST network.	LS CAN	XC90 only.
PDM	Passenger door module (PDM) Controls the functions in the passenger side door and communicates with the other modules via the network low speed side.	LS CAN
Carphone module	Phone module (PHM) Controls the functions of the carphone and communicates with the other modules via the network low speed side.	LS CAN	Option /accessory.
Power seat module	Power seat module (PSM) Controls the positions and functions of the driver's seat. Communicates with other control modules via the low speed side on the network.	LS CAN	Standard/ option NOTE: The power seat module (PSM) does not check seat heating and SIPS (side impact protection system) airbag function.
REM	Rear electronic module (REM) Controls the electrical functions in the rear section of the vehicle, and communicates with the other modules via the low speed side on the network. Contains a terminating resistor for the network.	LS CAN
RTI	Road traffic information module (RTI) Controls the road traffic information functions and communicates with the other modules via the low speed side on the network.	LS CAN	Option /accessory
Steering angle sensor	Steering wheel angle sensor module (SAS) Collects information about the steering angle and communicates with other control modules using the high speed side on the network.	HS CAN	Option. Used in the DSTC system.
SRS	Supplemental restraint system module (SRS) Controls the vehicle's crash safety system and communicates with the other modules via the low speed side on the network.	LS CAN
SUM	Suspension module (SUM) This control module handles the Four-C (Continuously Controlled Chassis Concept) function, i. e. constantly regulates damping in the shock absorbers. Communicates with other control modules via the high speed side on the network.	HS CAN	Option. Not XC90.
TCM	Transmission control module (TCM) Controls the automatic gearbox and communicates with the other modules via the high speed side on the network.	HS CAN	Vehicles with automatic transmission only.
Upper electronic module	Upper electronic module (UEM) Controls the electrical functions in the upper part of the passenger compartment. Also includes remote control receivers. Communicates with other control modules via the low speed side on the network. Contains a terminating resistor for the network.	LS CAN	Included in the interior rear view mirror. NOTE: There are two types of upper electronic module (UEM): one with an automatic dip function, and one without.