S80 L6-3.2L VIN 98 B6324S (2007)
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Which control module should do what (for example "you are the control module for the driver's door - you are the control module for the
passenger door").
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Which functions should be included (for example if the alarm function should be on or off).
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Which components are connected to the control modules (for example whether the inclination sensor is included in the alarm or not).
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Which messages a control module is to transmit and which it is to receive
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Where the different data should be stored.
Configuration must be adapted to the installation of accessories and must be downloaded again after any control module is replaced. Configuration is
adapted and downloaded via the diagnostic tool.
Note! Even if two cars appear identical they may behave differently because of differing configurations, a parameter may have been modified
by the customer or workshop.
Construction Of the Network
Construction of the network
General
The network is made up of a number of control modules (sometimes called nodes) that are connected to each other via two communication cables. Each
control module is individually powered and grounded and receives messages/commands via two the communication cables. In both networks (high and
low speed sides), the control modules are connected to a number of different spurs. In the event of an open circuit those control modules beyond the
open-circuit will not be able to communicate with other parts of the network. However, a failure in one of the spurs can lead to communication failure
with one control module while communication in the rest of the same network is working.
High and low speed sides on the network
The network consists of two parts. A high speed side (HS CAN) transmitting signals/messages between the central electronic module (CEM) and control
modules that are mainly in the engine compartment. A low speed side (LS CAN) transmitting signals/messages between the central electronic module
(CEM) and control modules that are mainly in the passenger compartment and cargo compartment.
The interface between the high and low speed sides is supplied by the central electronic module (CEM) which converts the transmission speed up or
down for communication between the two network sides.
Transfer speeds
The Volvo Controller area network (CAN) has two transfer speeds.
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HS CAN (high speed) has a transfer rate of 500 kbit/s.
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LS CAN (low speed) has a transfer rate of 125 kbit/s.
1 kbit/s = 1024 bits per second (1 byte = 8 bits).
For serial communication (Volcano Lite) between a control module and a slave control module the transfer rate is 9.6 kbit/s.
Terminating resistor
To prevent electrical reflections and interference in the CAN network, there are terminating resistors which bridge CAN H and CAN L. One at each end
on both the high and low speed sides of the network. Each terminating resistor has a resistance of 120 ohm.
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For the HS CAN (High Speed) the terminating resistor is in the Central electronic module (CEM) and the engine control module (ECM).
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For the LS CAN (Low Speed) the terminating resistor is in the Central electronic module (CEM) and Driver information module (DIM).
Both the terminating resistors create a parallel circuit The following resistors can be measured under specified conditions:
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When the control area network (CAN) is intact the resistance on each side of the network is approximately 60 ohm.
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In the event of a short-circuit between the communication cables, the resistance is approx. 0 ohm.
Error Management In the Controller Area Network (CAN)
Error management in the Controller area network (CAN)
General
The controller area network (CAN) is monitored by the Central electronic module (CEM). When the Central electronic module (CEM) detects a fault in
the controller area network (CAN) a diagnostic trouble code (DTC) is stored in the Central electronic module (CEM). There are different types of
diagnostic trouble code (DTC) depending on the type of fault.
Fault types which are processed are:
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No communication from the control module
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Faulty communication.
No communication from a control module
