Range Rover Evoque: Communications Network - Overview, System Operation and Component Description

Overview

A number of different types of communication networks are incorporated into the vehicle wiring harnesses for the transmission of commands and information between control modules. The configuration installed on a particular vehicle depends on the model and equipment level.

The communication networks available on the vehicle are:

• LIN (local interconnect network) bus
• Medium speed CAN (controller area network) bus
• High speed CAN bus
• Media Orientated System Transport (MOST) ring

System Operation and Component Description

Control Diagram

NOTE: O = LIN (local interconnect network) bus; N = Medium speed CAN (controller area network) bus; D = High speed CAN bus; P = MOST

CONTROL DIAGRAM - LIN BUS (SHEET 1 OF 2)

1. Immobilizer Antenna Unit (IAU)
2. Driver door module
3. Driver door switch pack
4. Rear door module (driver side)
5. Voltage quality module
6. Roof blind motor
7. Rear door module (passenger side)
8. Passenger door module
9. Rain sensor
10. Battery backed sounder (if fitted)
11. Front overhead console
12. Clockspring
13. Battery Monitoring System (BMS) module
14. CJB (central junction box)

CONTROL DIAGRAM - LIN BUS (SHEET 2 OF 2)

1. Headlamp control module
2. Generator (DW12c)
3. ECM (engine control module) (DW12c)
4. TCM (transmission control module)
5. Auxiliary battery module
6. Generator (GTDi)
7. ECM (GTDi)
8. Fresh/recirculated mode motor
9. Screen air distribution motor
10. RH (right-hand) air temperature mode motor
11. Cabin humidity sensor
12. Passenger heated seat module
13. Integrated Control Panel (ICP)
14. Driver heated seat module
15. LH (left-hand) air temperature mode motor
16. Face/feet mode air distribution motor
17. LH headlamp
18. RH headlamp
19. Radio Frequency (RF) receiver
20. Keyless Vehicle Module (KVM)

CONTROL DIAGRAM - MEDIUM SPEED CAN BUS

1. CJB
2. Integrated Control Panel (ICP)
3. Instrument cluster
4. Navigation system module (Asia)
5. Driver door module
6. Fuel Fired Booster Heater (FFBH)
7. Passenger door module
8. Passenger seat memory module
9. Rear view camera
10. Keyless Vehicle Module (KVM)
11. Liftgate module
12. RH blind spot monitoring module
13. LH blind spot monitoring module
14. Interior mirror
15. Driver seat memory module
16. Proximity camera control module
17. Diagnostic socket
18. Touch Screen Display (TSD) - single view
19. Touch Screen Display (TSD) - dual view
20. Multi-function display

CONTROL DIAGRAM - HIGH SPEED CAN BUS

1. CJB
2. ECM (GTDi)
3. ECM (DW12c)
4. Clockspring
5. Occupancy sensor module
6. Differential electronic module
7. TCM
8. Headlamp control module
9. Terrain optimization switch
10. ABS (anti-lock brake system) module
11. RCM (restraints control module)
12. Diagnostic socket
13. Electric steering column lock
14. Continuously variable damping module
15. Park distance control module
16. Electric park brake module
17. Instrument cluster
18. Electronic Transmission Selector (ETS)
19. Electrical power assisted steering rack
20. Gear shift module

CONTROL DIAGRAM - MOST

1. Diagnostic socket
2. Touch Screen Display (TSD)
3. Satellite Digital Audio Radio Service (SDARS) module (NAS Only) or Digital Audio Broadcasting (DAB) module
4. Rear Seat Entertainment (RSE) module
5. TV Module
6. Audio power amplifier
7. Integrated Audio Module (IAM)
8. Navigation control module (Japan only)

System Operation

Principles of operation

Refer to: Communications Network (418-00 Module Communications Network, Description and Operation). and to Component Description below.

Component Description

LOCAL INTERCONNECT NETWORK BUS

The LIN bus is a low speed broadcast network that employs master and slave components. The master component transmits a message along a single wire to the slave components identifying which slave is to respond. The 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 a message to the master component along the same wire.

CONTROLLER AREA NETWORK 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 2 wires.

Two CAN bus networks are used on the vehicle; medium speed and high speed, with the CJB acting as a gateway between the 2 networks. The table below shows the wire colors used on both networks.

MEDIA ORIENTATED SYSTEM TRANSPORT (MOST) RING

The Media Orientated System Transport (MOST) ring uses fiber optic cables to transport data and audio signals around the information and entertainment system. The fiber optic cables are arranged in a ring, with each unit on the ring having a 'MOST in' and 'MOST out' connection.

The MOST ring 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 integrated control module.

When handling MOST fiber optic cables the following precautions should be observed:

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

Ring Break Diagnostics

Incorporated into the CJB is a Ring Break Diagnostics (RBD) link. The RBD link houses a copper link which when removed initiates the ring break diagnostics mode. The ring break diagnostics mode allows the technician to locate an optical fiber break in the MOST ring. To initiate the ring break diagnostics mode, carry out the following process:

• Connect the Land Rover approved diagnostic system.
• Ensure the vehicle is in power mode 4 or greater.
• Remove the RBD link for the length of time specified by the Land Rover approved diagnostic system.
• Replace the RBD link.

After approximately 30 seconds a DTC (diagnostic trouble code) will be logged in the Integrated Control Module, identifying the location of the fault. The DTC can be read and interrogated using the Land Rover approved diagnostic system.

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