2429856 - Introduction - ELECTRICAL CIRCUIT FOR INSTRUMENTS/INDICATORS

GENERAL CHARACTERISTICS

In conventional electrical systems, functions are activated with the aid of dedicated point-to-point connections.As the number of eletrical/electronic devices on board new vehicles has increased, the connection are becoming more complex and heavy. One reason for this is the complexity of functions implemented in the many electronic units, which require a continual interchange of data. All this makes it more difficult to install new electrical systems and increases the complexity of fault diagnosis.Many problems have been resolved and new electrical systems have been optimised compared to conventional systems by means of networking. This provides a more effective means of managing communication on board the car and for the transfer of information between subsystems via the serial buses present: single wires, pairs of twisted wires or even optical fibres. We shall now see how the move from conventional systems to those known as multiplexing has taken place.

CLASSIC SOLUTION

The four control units in the diagram below require a number (N) of wires for each input/output in order to perform their function. This has created so much wiring that the system is more complex (design and manufacture), more bulky (weight, bulk and cost) and requires some 40 kg of wiring harnesses amounting to a length of more than 2 km. This requirement is likely to double every 10 years because even now one such vehicle may be equipped with 20 to 40 control units (ECUs).
1 - Climate control node 2 - Engine management node 3 - Engine temperature sensor (for engine management node) 4 - Instrument panel node 5 - Engine temperature sensor (for instrument panel warning light) 6 - Engine cooling fan 7 - Engine temperature bulb

CLASSIC SOLUTION

The first step that allowed us to reduce the volume and the complexity of the wiring harnesses was to group several electronic functions in a single unit: FEWER COMPONENTS = FEWER WIRES.

EXAMPLES OF INTEGRATION

The multi-function control unit manages: central locking, electric windows, courtesy light timer, heated rear windscreen timer and heated, exterior rear view mirrors.
1 - Multifunction control unit 2 - Central locking 3 - Electric window control unit 4 - Centre courtesy light 5 - Rear courtesy light 6 - Heated rear windscreen / heated door mirrors

EXAMPLES OF INTEGRATION

The integration of electrical/electronic functions in a single unit has allowed us to improve:

  • the management of current consumption
  • the functionality of appliances because they are managed by a single control unit;
  • the fault diagnosis using control unit self-diagnosis
This first stage has allowed us to reduce the number of electronic units but not to reduce the volume of wiring harnesses sufficiently.

MULTIPLEXING SOLUTION

This solution has made it possible to reduce the volume of cable looms and to considerably improve the transmission of information between the various electronic units.These transmissions take place through a BUS channel consisting of 2 cables (the main one already used for the telephone, radio, television network etc.)
A - B - C: NODES (CONTROL UNITS) D: MASTER CONTROL UNIT OR BODY COMPUTER A1 - A2, B1 - B2, C1 - C2: COMMUNICATION BUS

MULTIPLEXING SOLUTION

In addition to simplifying the wiring and improving communication between the electronic units, the multiplexing solution also makes it possible to reduce the number of sensors (INFORMATION SHARING)
A - Classic solution B - Multiplexing solution 1 - Climate control node 2 - Engine management node 3 - Engine temperature sensor (for engine management node) 4 - Instrument panel node 5 - Engine temperature sensor (for instrument panel warning light) 6 - Engine cooling fan 7 - Engine temperature bulb 8 - Instrument panel node 9 - Climate control node 10 - Engine temperature information 11 - Body Computer node 12 - Engine management node 13 - Engine temperature sensor (for engine management node)

MULTIPLEXING SOLUTION

In general, in order to send data via multiplexing, we need to define the following:

  • (A) THE TRANSMISSION CHANNEL (electric cables, optical fibres, radio waves, etc.)
  • (B) THE TYPE OF SIGNAL (voltage, current, light, etc.)
  • (B) THE COMMUNICATION PROTOCOL (all the rules that allow management of analogue or digital transmission management, code type, address, transmission order, error recording etc.).
On this model, the transmission channel (A) is a pair of electrical wires known as a BUS.The type of signal (B) is VOLTAGE and the communication protocol (C) is the CAN (Controller Area Network) developed by BOSCH.

F.L.ORE.N.C.E STRUCTURE

The MINI F.L.ORE.N.C.E systemhas been designed for the optimum management of the vehicle's electrical and electronic functions.The system interacts with all the electrical system functions, directly cotnrolling the so-called bodywork functions (visibility, access, on board information, comfort, telematics, etc.) and supporting the exchange of data between the traction control systems (engine, braking, gearbox, etc.).For excellent performance each control unit (electronic or electro-mechanical) is located in a central position in relation to the functions which it manages. This allows minimisation of the power and signal distribution system through the extensive use of serial communication networks, with advantages when solving the problems of size, reliability, weight and cost.The distribution of power takes place via 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 minimum degree of wiring complexity .

The MINI FLORENCE system offers countless advantages such as, for example:

  • the sensors in the various subsystems are made available to the network in order to be shared eliminating the presence of similar sensors
  • new functions can only be added by modifying the software (developed during the vehicle life),
  • wiring design is simplified and the number of connectors is reduced,
  • electronic device operating safety is increased to improve the reliability of information transmited,
  • an integrated diagnostic function simplifies service operations on electric/electronic components.

The system structure on this vehicle comprises:

  • 2 CAN communication NETWORKS which connect NODES belonging to two different areas: one for the dynamic control of the vehicle and one for the so-called 'bodywork' functions.
  • a serial line for immobiliser recovery
  • Different K SERIAL LINES for the fault diagnosis of several NODES / CONTROL UNITS
  • an A-BUS serial line
NODES refer to all the electrical / electronic devices and control units which contain a specific interface (NETWORK INTERFACE) which makes it possible to transmit and receive data, information and signals which travel through CAN networks.
Below is a table containing all the elements (nodes/control units/devices) which make up the mini FLORENCE structure for the most comprehensive configuration.Mini FLORENCE system components
CABAir bag control unit
CDCCD-Changer
CPLDashboard Control Unit
CSPRain/Dusk Sensor Control Unit
CVMEngine Compartment Control Unit
CVSClock Spring Cable
DSPAudio Hi-Fi Amplifier
NBCBody Computer node
NCRRobotized Gearbox Node
NCLClimate Control Node
NCMEngine Control Node
NFRBraking System Node
NGEElectrical steering node
NITTelematic Info Connector
NPGDriver's Door Node
NPPPassenger Door Node
NQSInstrument panel node
NRRRadio Receiver Node
CPAParking Sensor Node
NYLLateral Yaw Node (yaw sensor)
DEVSteering column switch unit

The two C-CAN and B-CAN networks are physically separate from one another, but both meet at the BODY COMPUTER NODE; the latter, which is considered the MASTER node for the two networks, contains a GATEWAY function which allows the transfer of information/dat from one network to the other, even if the two networks are operating at different speeds:

  • B-CAN NETWORK transmission speed = 50 Kbit/sec.
  • C-CAN NETWORK transmission speed = 500 Kbit/sec.
The fault diagnosis of the NODES connected to the B-CAN network is achieved via the CAN, whilst for those connected to the C-CAN require the specific K SERIAL LINES. The K lines and the B-CAN network meet in the connector for the EOBD fault diagnosis on the BODY COMPUTER.
Below is a diagram summarizing the structure of the mini F.L.Ore.N.C.E. system.'.

F.L.ORE.N.C.E STRUCTURE

Refer to the previous table for a description of the nodes.

B - CAN NETWORK CONNECTION

The B - CAN network (low speed) consists of 2 electrical cables, one White/Pink shown in the wiring diagram as a CAN - A cable and one Black/Pink one shown in the wiring diagram as a CAN - B cable.The transmission of information through this pair of cables takes place through the transmission of 2 voltage levels (V), one High and one Low associated with the CAN - A cable and the CAN - B cables, respectively. the mathematical difference between these two levels produces two voltage values associated with two logic levels, 0 or 1.The latter constitute the basic information unit known as BIT (binary digit) and, suitably combined, they make up the information to be transmitted.

B - CAN NETWORK CONNECTION

V Can A - V Can B = 3.6 - 1.4 = + 2.2 V (bit 0)V Can A - V Can B = 0.2 - 4.8 = - 4.6 V (bit 1)

C - CAN NETWORK CONNECTION

The C - CAN network (high speed) on the LANCIA Y consists of two twisted electrical cables, one Green, shown in the wiring diagram as the CAN - H cable and one Brown, shown in the wiring diagram as the CAN - L cable.The transmission of information is the same as that for the B - CAN network. in this case the High voltage level is associated with the CAN - H cable and the Low voltage level with the CAN - L cable.The mathematical difference for these two voltage levels for the C - CAN network also gives rise to two logic levels, 0 and 1, but with one difference illustrated in the diagram:

C - CAN NETWORK CONNECTION

The network interface cannot communicate at all if one of the following situations arises in the C-CAN network:

  • Break in one of the two CAN cables (H and L)
  • Short circuit between the two CAN cables (H and L)
  • Short circuit of the CAN - H cable or the CAN - L cable to +Vbatt.
  • Short circuit of the CAN - H cable of the CAN - L cable to earth.

PRIORITIES IN THE CASE OF A TRANSMISSION CONFLICT FOR SEVERAL NODES

The protocol for the mini Florence system can deal with problems of superimposition when several nodes wish to issue a frame simultaneously. A node sending a lower priority message interrupts its transmission immediately to make way for the node transmitting a higher priority signal. In practice, the higher priority message is sent via the network without any interruption or delay. - The frame with the highest priority gains the possibility of being transmitted through the BUS; a dominant level (0) always overcomes a recessive level (1).Simultaneous access of several control units to the network may give rise to conflict on the C-CAN line (BUS) the diagram shows that the engine control unit node (NCM) and the brake system control unit (NFR) send identical frames (data packages) up to point (D); from point (E) the two frames have a discordant bit.Because the NFR node is simultaneously checking (reading) the frame as well as transmitting it, from this moment on as soon as the NFR node realises that the bit it wishes tot transmit (1) of recessive value will come up against a bit (0) of dominant value in the network, it immediately interrupts transmission of its frame (loss of arbitrage) to give way to the NCM node, which is transmitting a higher priority frame. It stands by until the NCM node has finished transmitting and the line becomes free. The frame transmitted along the network is from the NCM node. The NFR may now re-attempt to gain access to the line to send the frame it tried to send previously. Provided another collision does not occur.

A - BUS LINE CONNECTION

The A - BUS serial line is designed to guarantee the exchange of information / commands between the various electronic control units.

On this vehicle, these control units are:

  • Steering column switch unit electronic module
  • Rain/dusk sensor
  • Body computer node
The transmission speed for the A - BUS is 4.8 kbit/sec.Communication at the A - BUS takes place through the exchange of data packages between the different control units.Each control unit connected to the A - BUS has its own electronic address; when one control unit has to send a command / information to another control unit, it must always enter the address of the destination control unit in the data package.Transmission always takes place from a transmitting control unit to a receiving control unit (one-way).When the data reception is complete, the receiving control unit should send the outcome to the transmitting control unit, thereby ending the data package exchange.Unlike the CAN NETWORKS, the transmission priorities at the A - BUS are assigned to each control unit and not to the information to be transmitted, therefore the control unit access sequence in the case of a transmission conflict is decided at the design stage.

LINE K CONNECTION

In the mini F.L.Ore.N.C.E. system the K lines make it possible to carry out fault diagnosis using the diagnostic equipment for the following Nodes / Control Units:

  • Electric steering node (NGE)
  • Gearbox/Robotised Gearbox (NCR)
  • Engine Management Node (NCM)
  • Brake Node (NFR)
  • Air Bag Control Unit (CAB)
  • Parking Sensor Control Unit (CPA)

SPECIFICATIONS

The BODY COMPUTER NODE manages some of the vehicle's electrical system functions.The NBC is housed under the dashboard near the steering column, in a central position in relation to the functions that it manages.The Body Computer Node (NBC) together with the Dashboard Control Unit (CPL) form the DASHBOARD NODE (NPL) where the former (NBC) constitutes the electronic section and the latter (CPL) the electro-mechanical section.The fuses and relays are fitted on the CPL, whilst the NBC houses the EOBD fixed connector used for the fault diagnosis via the K lines of the NCM, NFR, NCR and CAB.This is connector is also prepared for the dialogue with the B - CAN and C - CAN networks which can be used for both fault diagnosis and for possible on line programming.

BODY COMPUTER NODE GENERAL FUNCTIONS

The NBC peforms the following functions:

  • It receives and sends information on the B - CAN network (e.g.: fault diagnosis, warning lights, commands, data)
  • It receives and sends information on the C - CAN network
  • It interconnects with the dashboard, front and rear wiring
  • It allows an interface for the fault diagnosis (EOBD)
  • It connects to the CPL to take power supplies / signals and operate relays.

We find the following functions:

  • management of the courtesy lights with timed switching off and dimming
  • management of on/off exits at relay: headlamp washer pump, main beam headlamps, fog lights, dipped headlamps, services, heated rear windscreen
  • on/off management of relay during right/left direction indicators or hazard warning lights for acoustic feedback
  • on/off output management directly at the loads and lights check function: front side lights (left and right) and rear side lights (left and right), front direction indicators (left and right), rear direction indicators (left and right), and side repeaters (left and right), number plate lights (left and right), brake lights (left and right), rear fog lamps (left and right);
  • management of on/off exits directly at loads: heated rear windscreen LED, hazard warning lights LED;
  • repetition of the vehicle speed signal
  • management of the ideogram light driver
  • management of the SBMT driver (load disactivation at key-off)
  • management of the recovery serial line to the engine management control unit (immobilizer)
  • management of the serial line for the tilt sensor, rain sensor, steering column switch unit.
  • master for the entire system: management of the IFRs at the slave nodes under direct jurisdiction and monitoring of the IFRs by the other master nodes, monitoring and management of protocol errors, timer control;
  • fault diagnosis of the entire system: collection of diagnostic information, management of the fault diagnosis using the EXAMINER.
  • immobilizer: management of the key code with possible engine immobilizing
  • acquisition of on/off signals: dipped headlamp operation, main beam headlamp operation, boot lock opening control, boot locking function, handbrake control, hazard warning lights control, left and right rear fog lamps control, fog lights relay feed, left direction indicators control, right direction indicators control, parking lights control, side lights control, city control, steering column switch unit auto control, headlamp washer control, FIS control, boot button, bonnet button, front brake pad wear (left and right), brake fluid level, reverse gear engaged;
  • acquisition of analogue signals: fuel level, alternator voltage (D+), battery voltage, brake lights fuse status recognition, centre courtesy light control, left and right spot lights control, brake lights control
  • acquisition of vehicle speed signal
  • acquisition of lock sensors from door.
1 - Body Computer Node (NBC) 2 - Dashboard Control Unit (CPL) NBC+CPL = NPL

BODY COMPUTER NODE GENERAL FUNCTIONS

.
A - Body Computer Node (NBC) front view B - Body Computer Node (NBC) rear view 1 - Connector F 2 - Connector D/E 3 - Connector C (EOBD tester output) 4 - Connector A/B 5 - Connector G 6 - Connector H 7 - Connector I

BODY COMPUTER NODE NBC PIN OUT

Connector F (20-way)
PinOperation
relaySupply for boot release gear motor
relayButton on brake pedal status input
3Button for switching on reversing lights status input
4Not available
5Low speed CAN line
6Heated rear windscreen relay control output
7Low speed CAN line
8Dipped headlamp relay control output
9INT from ignition switch
10Preparation for boot lock
11.Boot release geared motor control
12.Parking light input
13INT for instrument panel
14Service relay control output
15INT from ignition switch
16Not available
17Supply for front rear courtesy light, climate control, tester output
18Power supply for Body Computer
19Dedicated power supply for direction indicators and hazard warning lights
20Dedicated earth for release geared motor

BODY COMPUTER NODE NBC PIN OUT

Connector D/E
PinOperation
relayDriver's door open status input for NCR
relayOperation of left side repeater
3Right rear direction indicator control output (21W)
4Fuel level input
5Left rear side light control output (5W)
6Right rear side light control output (5W)
7A-bus serial line for CSP
8Input signal from normally open switch signalling front driver's door open
9Left no. plate light control output
10Sun roof control unit output (NC)
11.Negative signal for front passenger door open
12.Left rear direction indicator control output (21W)
13Operation of side direction indicators left
14Hanbrake lever button status input
15Fuel level input (negative)
16Left rear door open status input
17Inertia switch signal input
18Serial line for CPA
19Signal from city button
20Right rear fog lamp control output
21Centre courtesy light control output
22Right brake light control output
23Interior light control output (boot compartment)
24Signal from boot lock catch (locking enablement)
25Input signal from normally open switch signalling front passenger side open
26Input signal from normally open switch signalling right rear door open
27Supply for front/rear courtesy light
28Analogue input for switching on left/right spot light and excluding front/rear courtesy light in centre courtesy light
29Positive from antitheft device (provision)
30Left spot light control in centre front courtesy light
31Left rear fog lamp control output
32Left brake light control output
33Passenger compartment interior ilght control output (NC)
34Negative signal from switch (preparation)
35Signal from opening switch on boot handle
36Signal from normally open switch signalling boot open
37Right spot light in centre front courtesy light control output
38Right no. plate light control output
39Aerial power supply
40Internal serigraphy lighting control output

BODY COMPUTER NODE NBC PIN OUT

Connector C (EOBD tester output)
PinOperation
relaySerial line K for NFR
relayNot available
3Serial line for Air Bag CAB
4Power earth
5Signal earth
6Low speed CAN line
7Serial line for NCM/NCR diagnosis
8K line for immobiliser
9Serial line for NGE
10Not available
11.Not available
12.Serial line (NC)
13Passing signal line for rear (PARK)
14Low speed CAN line
15Line L (NC)
16Supply tester output

BODY COMPUTER NODE NBC PIN OUT

Connector A/B
PinOperation
relayButton input for reversing light activation
relayLeft side direction indicator control output (5W) (NC)
3Screen fitting for Immobilizer
4Immobilizer aerial
5Immobilizer aerial
6Serial interface (provision)
7Speedometer input from NFR
8Output for fog lights relay control
9Output for main beam headlamps control
10Provision
11.Provision
12. Provision
13Headlamp washer request wish-wash signal input
14Headlamp washer relay control output
15Speedometer input signal earth for gearbox
16Braking node line K
17Speedometer signal input coming from robotized gearbox
18Brake system fluid level input
19Battery recharging warning from alternator D+ input
20K line for testing NCM, NCR
21RF receiver aerial earth
22Left side direction indicator control output (5W) (NC)
23Brake pad wear state input
24Bonnet button status input (NC)
25A-bus serial line for DEV
26Low speed CAN line for NCL
27Low speed CAN line for NCL
28Speedometer repeater output for NCRF
29IN/OUT recovery serial for NCM in case of break in C-CAN line
30Right front side light control output (5W)
31RF receiver aerial
32High speed CAN line
33High speed CAN line
34Antitheft siren power supply (NC)
35Serial line K for CPS
36High speed CAN line to NCM
37High speed CAN line to NCM
38Left front direction indicator control output (21W)
39Right front direction indicator control output (21W)
40Left front side light control output (5W)

BODY COMPUTER NODE NBC PIN OUT

Connector G/H/I (9+18+9 way)
PinOperation
relayFoglamp activation request input
relaySteering column switch unit exterior lights auto mode activation signal
3Dedicated power supply for direction indicators driver and NQS serigraphy
4Dipped headlamps switch status input
5Low speed CAN line from NQS
6Low speed CAN line from NQS
7Right parking light/direction indicators control input
8Signal earth
9Power earth
10Power earth
11.Serial line K for NGE
12.Serial K line for CAB
13Negative control for LED (provision)
14Positive control for LED signalling anti-theft device on (preparation)
15+30 SBMT (passenger compartment lights)
16Passenger compartment interior lights control output
17Parking light signal (NC)
18Screen print lighting control output
19Signal earth
20Fog lamp control negative signal
21Heated rear windscreen LED control output
22Fog lights on LED negative control
23Speedometer repeater output for CTA
24Low speed CAN line for NVO, NBS (NC)
25Low speed CAN line for NVO, NBS (NC)
26Supply NCC climate control unit
27INT. for CPL
28Side lights switch status input
29Hazard warning lights LED control output
30Left direction indicators/parking light control input
31INT for NQS
32Heated rear windscreen button status input
33Main beam headlamps switch status signal
34Hazard warning lights switch status input
35Rear fog lamp button status input
36NQS signal earth
Some CAN nodes are programmed with default settings that the customer will find upon purchasing the vehicle.

The following nodes store such information:

  • Body Computer
  • Instrument panel
  • Climate control unit
If the Body Computer is replaced, an identical copy of the Body Computer should be ordered from parts as a rush delivery, giving the vehicle chassis number. This copy will contain all the default settings entered when the vehicle was new that are stored in the Parts database with the vehicle chassis number.
If the Instrument Panel or Climate Control Unit is replaced, Parts will send a blank component: once this is fitted: transfer intial default data to the unit and run the PROXY ALIGNMENT procedure using an Examiner.
If other nodes are repladced, no initialisation procedure is necessary. Always use an Examiner to check that the system has not acquired errors during removal-refitting operations etc.

battery disconnection

If the battery is disconnected:

  • Body Computer,
  • Instrument panel
  • Climate Control Unit
store all information received and must not be initialised after battery disconnection.