Volvo Workshop Manuals
XC70 L5-2.5L Turbo VIN 59 B5254T2 (2003)
Powertrain Management > Computers and Control Systems > Information Bus > Component Information > Description and Operation > The Controller Area Network (CAN) > Page 4310
Before the introduction of the network the installation of control modules, switches, vacuum pumps, vacuum servos, hoses and cable harnesses was
Easier to introduce logical functions
Logical functions can be explained as "if this occurs then the following corrective action must be carried out". For example, the system is programmed so
Easy to adapt the system to customer and market requirements
The functions can be altered depending on the requirements of the customer and market. An example of this could be fog tail lamps. Certain markets use
Similar basic systems can be used for a whole model program
Similar networks (hardware) can be used for a large number of different cars.
the components (control modules, sensors controlled components etc.) which are connected to the system
Which components do what
Which components/functions are standard /optional/accessories
The configuration /programming of the system.
The Network Construction
The network construction
The network is made up of a number of control modules (sometimes called nodes)which are connected to each other serially via two communication
High and low speed sides on the network
The network consists of two parts. A high speed side which transfers (HS CAN) signals/messages between the central electronic module and the control
The Volvo Controller area network (CAN) has two transfer speeds.
HS CAN (High speed) has a transfer speed of 250 Kbps
LS CAN (Low speed) has a transfer speed of 125 Kbps.
1 Kbps = 1024 bit per second (1byte = 8 bits).
To prevent electrical reflections and interference in the Controller area network (CAN) there are terminating resistors which bridge CAN H and CAN L.
The terminating resistor for the high speed Controller area network (CAN) is positioned in the brake control module/ABS control module and in
There are terminating resistors for the low speed Controller area network (CAN) in the upper electronic module and the rear electronic module.
Both the terminating resistors create a parallel circuit The following resistors can be measured under specified conditions:
When the Controller area network (CAN) is intact the resistance in the network is approximately 60 ohm
In the event of an open-circuit in the wiring, the resistance in the network is approximately 120 ohm
|[PREV PAGE] [NEXT PAGE]|