LR3/Disco 3
A number of different types of data bus are incorporated into the vehicle wiring harnesses for the transmission of
commands and information between ECU’s. The bus configuration installed on a particular vehicle depends on the model
and equipment level.
The available types of bus systems on the vehicle are:
High speed Controller Area Network (CAN) bus
Medium speed CAN bus
Media Orientated System Transport (MOST) bus
Gigabit Video Interface (GVIF)
Local Interconnect (LIN) bus
Security Local Interconnect (SLIN) bus
Controller Area Network (CAN)
The CAN bus is a high speed broadcast network where the ECU’s automatically transmit information on the bus every few
microseconds. The other buses are low speed networks which are mainly event driven, i.e. an electronic control module
outputs a message only in response to a request message from another ECU or a hard wired input from a switch or
sensor.
A twisted pair of wires are used for the CAN bus and single wires are used for all of the other buses. Bus wires can be
repaired using crimped connections. The unwound length of CAN bus wires must not exceed 40 mm (1.6 in).
Two CAN busses are employed on the vehicle:
Medium speed
High speed
The medium speed bus connects the following control modules:
Integrated Head Unit (IHU) or low line head unit
Heating and ventilation control module
Fuel burning heater
Park distance control
Tyre pressure monitoring control module
Central junction box
The high speed bus connects the following control modules:
3
-
Park Distance Control (PDC) module
4
-
Central Junction Box (CJB)
5
-
Rain senor
6
-
Memory control module
7
-
Sunroof control module
8
-
Battery backed up sounder (BBuS)
9
-
ABS control module
10
-
Automatic Front Lighting System (AFS)
11
-
Transfer box control module
12
-
Transmission control module
Bus
Baud rate
Protocol
High speed CAN
500 kbits/s
11898
Medium speed CAN 125 kbits/s
11898
MOST
24 Mbs
MOST Cooperation
GVIF
1.95 Gbps Sony proprietary system
LIN
9.6Kbs
LIN consortium
