XC90 FWD L6-3.2L VIN 98 B6324S (2007)
The Network
The network
General
Increasing demands for further functionality in the car, both by statutory requirement and customers, have led to an increased complexity in the car.
This, in turn, has encouraged developments towards more flexible electrical systems. The CAN network is a result of this research (CAN = Controller
Area Network). The network permits the transmission and receipt of a large number of different commands and messages on the same wires. Every
command or message used to require a separate wire. Using networks has allowed functionality to be expanded without increasing the number of wires.
The number of commands and messages that can be handled by the network depends on the speed of the network and the length of the
message/command. The Volvo network which is based on a Controller Area Network (CAN), can transmit over 500 different signals and approximately
100 messages (also known as frames). Each message can contain several signals, for example a message to the rear electronic module (REM) can contain
all the signals for how the tail lamps should be lit.
Advantages of a network
Easier to add further functions and install accessories.
Because the control modules in the network are already connected to each other and are easy to add more information to, all that is required is:
-
to connect the sensors to the nearest control module
-
to connect the controlled component to the nearest control module
-
to download software to alter the configuration and programming of the network.
The length of the wiring and the number of components which are introduced with the car are less than previously.
An example of this is the addition of cruise control for the car.
Before the introduction of the network the installation of control modules, switches, vacuum pumps, vacuum servos, hoses and cable harnesses was
necessary.
With the network only the installation of a switch and the downloading of software which alters the configuration of the car is required.
Easier to introduce logical functions.
Logical functions can be described as "if this happens, the following must take place". For example, the system is programmed so that if a tail lamp
breaks, a message is transmitted via the CAN network to the driver information module (DIM) so as to warn the driver.
The only thing you need to do to introduce a logical function is alter the programming of control modules affected - the rear electronic module (REM)
