Module Communications Network: Other Jaguar XKR II

CONTROLLER AREA NETWORK (CAN) BUS

The CAN bus is a high speed broadcast network where control modules automatically transmit information every few microseconds. Information is broadcast down a pair of twisted wires, known as 'CAN high' and 'CAN low'. Information is transmitted on the CAN bus as a voltage difference between the two wires.

Two CAN bus networks are used on the vehicle; medium speed and high speed, with the instrument cluster acting as a gateway between the two networks. The table below shows the wire colors used on both networks.

Private CAN bus

The private CAN bus networks used on the vehicle can be either medium or high speed depending on which vehicle system they are being used. All private CAN bus networks are proprietary systems and cannot be interrogated using the Integrated Diagnostic System (IDS).

MEDIA ORIENTATED SYSTEM TRANSPORT (MOST) RING

The MOST ring uses a fibre optic cable to transport data and audio around the information and entertainment system. The fibre optic cable is arranged in a ring, with each unit on the ring having a 'MOST in' and 'MOST out' connection.

MOST is a synchronous network. A timing master supplies the clock and all other components on the ring synchronize their operation to this clock. The timing master for the MOST ring is the Information and Entertainment control module.

When handling MOST fibre optic cables the following precautions should be observed.

1. After disconnection of any cables, carefully install appropriate dust caps to protect the mating faces of the connectors from damage or contamination.
2. Avoid introducing bends of less than 25 mm (0.98 inches) radius or kinks into the fibre optic cable during service or repair. Tight bends or kinks could impair operation, cause immediate system failure, or future system failure.
3. Avoid excessive force, strain or stress on the fibers and connectors, especially permanent stress after reinstallation.

Software Download Socket

The MOST software download socket is located below the drivers side of the instrument panel. A service loop is fitted to the end of the socket to complete the MOST ring. If the service loop is removed the MOST ring will be broken and all components on the ring will stop operating.

Note. The software download socket is used for engineering purposes only and must not be used in service.

LOCAL INTERCONNECT NETWORK (LIN) BUS

The LIN bus is a low speed broadcast network that employs master and slave components. The master component transmits a message to the slave components identifying which slave is to respond. This message has a header (slave identifier) and an empty data field. The identified slave component fills the data field with the relevant information and returns the message to the master component.

Unlike the CAN bus networks, the LIN bus utilizes a single wire network.

Scheme 3

Note. N = Medium speed CAN bus

Note. Only the buttons of the Integrated control panel are connected to the medium speed CAN bus. The Touch Screen Display (TSD) is connected to the MOST ring.

Scheme 4

Note. D = High speed CAN bus

Scheme 5

Note. P = MOST ring

Scheme 6

Note. P = MOST ring

Scheme 7

Note. O = LIN bus; U = Private CAN bus

Rear Junction Box (RJB)

Central Junction Box (CJB)

Scheme 8

Scheme 9

1. Remove the cover and disconnect the battery ground cable. Refer to «Specifications»(ref-312541) article.
2. Release the auxiliary junction box access cover. Release from the clip.
3. Release the auxiliary junction box. Disconnect the 10 electrical connectors. Disconnect the battery positive cable.
4. Remove the auxiliary junction box. Remove the 2 nuts.