841006394 - E1050 CAN CONNECTION LINES DESCRIPTION

Description

This vehicle is equipped with a CAN (Controller Area Network) system of electrical connections it involves a software and hardware solution which is designed to manage the resources on the vehicle efficiently allowing:

  • the sharing of information between the various electronic units;
  • the intergration of several electronic units through the network;
  • a high network information exchange speed;
  • advantages in economic terms because there is a considerable reduction in the wiring/connectors inside the vehicle;
  • considerably improved quality and reliability.
The advantage of using a CAN system stems from the fact that the communication between the various electronic control units takes place with a large number of signals to be managed.For this reason the signals travel on a CAN type serial bus where one wire is high level (H) and the other low level (L); these signals on the CAN bus are differential types, i.e. the value assigned to the bit is represented by the difference between the CAN-H and CAN-L voltage levels.The different electronic units which make up the system, known as network nodes, are connected to the CAN by means of communication interfaces known as transreceivers; these connection interfaces, integrated in the electronic units, constitute the gate for sending/reading the information at the CAN or at the serial lines.The exchange of information at CAN type serial lines is only possible using a transmission protocol which is the collection of rules that allow communication between two or more nodes.The main element of the network is the body computer.The body computer control unit is entrusted with waking up the network when the ignition key is turned to the ON (INT) position, if there is a problem with the body computer this task is entrusted to the instrument panel.The body computer also carries out the functions of checking the network which make it possible to provide information on:

  • the network activities status;
  • the functional failure status of the individual electronic units (nodes);
  • a possible CAN failure status.
The various electronic units process the various signals coming from the corresponding sensors both for their own management and for other control units to which they are sent via the CAN.The structure consists of three CAN communication networks which connect nodes belonging to the three different areas (vehicle dynamic control and bodywork functions) and a certain number of complementary serial lines used for diagnosis and other specific functions:

  • C-CAN for dynamic vehicle control (high speed);
  • B-CAN for the management of standard bodywork functions (low speed);
  • I-CAN for transporting data and commands relating to on-board information (low speed);
  • w serial line for immobilizer recovery (release code at the engine management control unit when the C-CAN at the Body Computer is not working properly);
  • k diagnostic line for the engine management control unit / automatic transmission control unit;
  • k diagnostic line for the Air Bag control unit;
  • k diagnostic line for the braking system control unit;
  • k diagnostic line for the dashboard area (power steering control unit, headlamp alignment corrector control unit)
  • k diagnostic line for the rear area (electric braking control unit, controlled suspension control unit);
  • k diagnostic line for the front area (cruise adaptive control unit, braking system check control unit, additional heater control unit);
  • A-BUS serial line for management of wipers, safety, exterior lighting which connects the body computer, roof control unit, alarm siren control unit, windscreen wiper cotnrol unit;
  • serial line for info-telematic control unit/climate control system control unit for data display;
  • two-way serial line for body computer/rear lights control unit for the fault diagnosis of the rear light clusters.
The C-CAN and B-CAN networks are connected to one another by a gateway for transferring joint information located in the body computer.The fault diagnosis of the nodes connected to the B-CAN is carried out via the CAN, whilst for those connected to the C-CAN this is carried out by means of the specific K lines    See E8010 DIAGNOSTIC MULTIPLE CONNECTORBoth flow into the EOBD connector on the Body Computer.The following nodes are connected to the body computer via the C-CAN:

  • the engine management control unit;
  • the braking system control unit;
  • the braking system control unit;
  • the electric braking control unit;
  • the slewing control unit;
  • the steering angle control unit;
  • the steering geometry control unit;
  • the cruise control system control unit.
The following nodes are connected to the Body Computer via the B-CAN:

  • the climate control system control unit;
  • the steering wheel node control unit;
  • the driver''s door control unit;
  • the passenger door control unit;
  • the roof control unit;
  • the luggage compartment control unit;
  • the passive entry control unit;
  • the parking sensors control unit;
  • the instrument panel control unit;
  • the steering lock control unit;
  • the info-telematic control unit.
The following are connected via the I-CAN:

  • the info-telematic control unit to the TV tuner, managing the television controls.
The power distribution takes place by means of the junction units and/or fuse boxes, connected to the control elements (relays and static actuators) in order to ensure the maximum level of electrical protection and the least complex wiring    See E1010 SUPPLY