Scheme 1
Principles of Operation
The vehicle has four module communication networks. Only three of which are connected to the diagnostic connector. The standard corporate protocol (SCP) and controller area network (CAN), which are an unshielded twisted pair cable: data bus + and data bus - and the International Standard Organization (ISO) 9141 communication network, which is a single wire network.
The domestic data bus (D2B), which is a fibre optic ring network, can be diagnosed through the SCP network, and with the optical bus tester.
The SCP, CAN and ISO networks can be connected to the Jaguar approved diagnostic system by one diagnostic connector. This makes troubleshooting these systems easier by allowing one smart tester to be able to diagnose any module on the three networks from one connector. On-board diagnosis of the D2B network is through the in car entertainment (ICE) head.
The diagnostic connector is located under the instrument panel.
The ISO 9141 communications network does not permit inter-module communications. When the Jaguar approved diagnostic system communicates with modules on the ISO 9141 communication network, the diagnostic system must ask for all information, the modules will not initiate communications.
The SCP communication network remains operational even with severing of one of the bus wires. Communications will also continue if one of the bus wires is shorted to ground or battery positive voltage (B+), or if some (but not all) termination resistors are lost.
Unlike the SCP communication network, the ISO 9141 communication network will not function if the wire is shorted to ground or battery positive voltage (B+). Also, if one of the modules on the ISO 9141 network loses power or shorts internally, communication to that module will fail.
The anti-lock brake control module is connected to the CAN communication network. The module comes in two forms. The first type is the standard equipped anti-lock brake system (ABS) with traction control. It controls the brake pressure to the four wheels to keep the vehicle under control while braking. The second type of ABS is optional and is called dynamic stability control (DSC). This module adds yaw and steering wheel angle sensors to the package to help in sensing a loss of vehicle control. For additional information, ANTI-LOCK CONTROL - STABILITY ASSIST
The in car entertainment (ICE) head is connected to the SCP communication network and also to the D2B network.
The D2B communicates with the compact disc player, cellular phone transceiver, navigation system, amplifier, and the voice control module. For additional information on the compact disc, AUDIO SYSTEM For additional information on the cellular phone, CELLULAR PHONE For additional information on the navigation system, NAVIGATION SYSTEM For additional information on the amplifier, AUDIO SYSTEM For additional information on the voice activated control system, MULTIFUNCTION ELECTRONIC MODULE
The electronic automatic temperature control (EATC) module is connected to the CAN communication network. The EATC module controls automatic climate functions that maintain the vehicle at a constant temperature setting. For additional information, CLIMATE CONTROL SYSTEM
The instrument cluster (also known as an instrument cluster module ICM) is connected to the CAN and SCP communication networks. The instrument cluster displays information received on the SCP including speedometer, odometer, fuel, and message center warnings. The instrument cluster displays information received on the CAN including ABS, air conditioning, transmission and engine condition. The instrument cluster also controls the passive anti-theft system (PATS). For additional information; INSTRUMENT Cluster and Panel Illumination For instrument cluster operation and ANTI-THEFT - PASSIVE for PATS.
The general electronic module (GEM) is connected to the SCP communication network. The GEM controls both interior and exterior lighting, active anti-theft functions and warning chimes. For additional information on interior lamps, INTERIOR LIGHTING For additional information on exterior lighting, HEADLAMPS For additional information on active anti-theft, ANTI-THEFT - ACTIVE For additional information on warning chimes, WARNING DEVICES
The engine control module (ECM) is connected to both the CAN and ISO 9141 communication networks. The ECM controls the engine performance, electronic ignition, emission controls, speed control, and on board diagnostics. For additional information; ELECTRONIC ENGINE CONTROLS - 2.5L/3.0L , ELECTRONIC ENGINE CONTROLS - 2.0L or
The 'phone module is connected to the D2B communication network, and incorporates the VEMS, or Vehicle Emergency Messaging System. The module allows a user to request emergency assistance (police, ambulance, fire, recovery) or directions to a desired location at the touch of a button. Also, if any of the vehicle's airbags are deployed while the VEMS system is powered ON, the system automatically issues a call for emergency assistance. For additional information
The airbag restraints module is connected to the ISO 9141 communication network. The airbag control module controls the deployment of the air bags based on sensor input. For additional information
The voice activated control module (VACM) is connected to the D2B communication network. This allows the user to select functions by giving a voice command. The VACM sends the command information by D2B to the correct module or audio unit.
The navigation system (NAV) is connected to the D2B communication network, and performs it's diagnostics via the SCP network. The NAV receives inputs from the GPS antenna and various other sensors. For additional information, NAVIGATION SYSTEM