BSI - The inside story.

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Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
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This is the BSI tear-down, a similar COM2000 tear-down is here

The BSI - The inside story is a work in progress (now complete - see BSI - the inside story and will expand as I get more free time and any extra information is gratefully received, including actual BSI units, dead or alive. This particular BSI is from a 2002 model, with the 2006 BSI having a different fuse layout.

If you need to get to this point, the instructions on how to remove the BSI from the car can be found in the topic by omarsmith, titled BSI removal


The BSI - (Body Systems Interface) is the 'heart' of the computer systems found in the Citroen C3. All the other computer system are connected to the BSI. The BSI is an ECU (Electronic Control Unit) in its own right which takes inputs from the controls under the steering wheel (stalks) and outputs wipers, lights, window motors, door locks, sunroof, and electric mirrors. It also has a connection to most of the other electrical features of the car. You will also notice the BSI carries many of the fuses for the car.

The Citroen C3 BSI - out of the car.
The Citroen C3 BSI
The Citroen C3 BSI
The Citroen C3 BSI - out of the car, with the top cover removed reveals 2 circuit boards linked together.
Citroen C3 BSI with the top cover removed
Citroen C3 BSI with the top cover removed
The 2 boards can be clearly seen overlapping each other in this picture
Citroen C3 BSI showing 2 circuit boards
Citroen C3 BSI showing 2 circuit boards

The 2 circuit boards perform different and distinct functions and are linked together with some soldered in stand-off connectors.

This is the 'power' board. It is populated with the Fuses, Relays, Diodes and connectors. The connector are all heavy duty, power connectors.
Citroen C3 BSI power board separated
Citroen C3 BSI power board separated

The 6 relays on the power board are made up of:
V23076-A3001-D142, V23076-A3001-C132 and V23076-A3001-D133 by TYCO, have a look here for some V23076 relays and select the correct one you need from the list if you are given a choice.

Image



and three 51ND10-W1 relays

Image

(similar to 51ND12-W1 (Fujitsu 12v Coil))


Three 1.5KE39CA Bi-directional Transient Voltage Suppressor Diodes also appear on the board.


Image
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My Name: C3CAR

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Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
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This is processor board. I has some memory, a microprocessor, some solid state relays and some connectors. There are also a few, as yet, unidentified components.


Citroen C3 BSI Processor - Logic Board
Citroen C3 BSI Processor - Logic Board
It has been separated from the power board to show the full board as the power board overlaps the logic board.

and the underside is shown below.

BSI underside of logic/processor board
BSI underside of logic/processor board
Components of the processor board include:

A82C250 CAN (controller area network) controller.
A82C250 CAN controller
A82C250 CAN controller
A82C250-CAN_controller.jpg (4.69 KiB) Viewed 23750 times

BTS840S2 Smart High-Side Power Switch (Solid State Switch with diagnostic feedback)
BTS840S2 Smart High Side Power Switch
BTS840S2 Smart High Side Power Switch

C1413BD High Power Transistor Array
C1413BD High Power Transistor Array
C1413BD High Power Transistor Array

D76F0018 Single Chip Microcontroller/Microprocessor with CAN (controller area network) and VAN (Vehicle Area Network) interfaces
D76F0018GJ Microprocessor
D76F0018GJ Microprocessor

Yet to have its function defined is the Motorola GEC44 3A
Motorola-GEC44-3A
Motorola-GEC44-3A

ST95160 Serial EEPROM (Electrically Erasable Programmable Read-Only Memory)
ST95160 Serial EEPROM
ST95160 Serial EEPROM
ST95160-Serial_EEPROM.jpg (4.14 KiB) Viewed 23750 times

ST2903 Dual Differential Comparators
ST2903 Comparator
ST2903 Comparator

VNQ660SP - A Quad Channel High Side Solid State Relay
VNQ660SP Solid State Relay
VNQ660SP Solid State Relay
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My Name: C3CAR

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Joined: Wed May 04, 2011 10:01 am
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
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The 3 BSI variants and how to identify them by the car specification.
Citroen C3 BSI variants
Citroen C3 BSI variants
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My Name: C3CAR

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Joined: Wed May 04, 2011 10:01 am
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
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BSI Pinout Diagram (Work in progress)
BSI Connection diagram and socket identification for the C3
BSI Connection diagram and socket identification for the C3
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My Name: C3CAR

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Joined: Wed May 04, 2011 10:01 am
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
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.3. Electronics section connector
The connectors of the electronics section mainly group together the "inputs" of the built-in systems interface (BSI).
Connectors
NameDescriptionConnector typeNumber of channelsColour of harness connected
EPElectronic connector to main harnessMQS40-wayBlack
EAElectronics connector towards accessoryMQS6-wayBlack
EH1Electronic connector to passenger compartment harnessMQS40-wayWhite
EH2Electronic connector to passenger compartment harnessMQS40-wayGrey
1.4. Power section connector
The connectors of the power section mainly group together the "outputs" of the built-in systems interface (BSI).
Connectors
NameDescriptionConnector typeNumber of channelsColour of harness connected
PH1Connector power to passenger compartment harnessSICMA 216-wayBlack
PH2Connector power to passenger compartment harnessSICMA 216-wayGrey
PPConnector power to main harnessSICMA 216-wayGreen
PBPower connector to dashboard harnessCINCH10-wayBlack
1.5. Built-in systems interface supply connector (BSI)
Connectors
NameDescriptionConnector typeNumber of channelsColour of harness connected
AASupply of the BSI in ACC+ and ignition+ coming from the ignition switchSICMA 22-wayBlack
APBSI supply coming from the engine fusebox via the maxi fuses 4 and 5NG1 8mm2-wayGrey
2. Allocation of the ways of the connectors
2.1. Connector EP
-waysignalNature of signal
1Engine coolant low inputAll or nothing
2CAN HIGH multiplexed signalmultiplexed
3Front windscreen wipers park inputAll or nothing
4CAN LOW multiplexed signalmultiplexed
5Front windscreen wiper relay outputAll or nothing
6BODY VAN 1 DATA signalmultiplexed
7Line K (diagnosis)-
8BODY VAN 1 DATA/B signalmultiplexed
9Front LH direction indicator and repeater output-
10Front LH direction indicator and repeater output-
11Input/output: alternator excitation-
12Piloted manual gearbox outputAll or nothing
13Engine oil level input/outputAnalogue
14Earth for the engine oil level and temperature measurements-
15Earth for the fuel level measurement-
16Fuel level measurementAnalogue
17Refrigerant temperature measurement (air conditioning evaporator)Analogue
18Earth for the refrigerant temperature measurement (evaporator)-
19Front RH direction indicator and repeater output-
20Front RH direction indicator and repeater output-
21--
22Brake fluid low inputAll or nothing
23Headlamp wash low inputAll or nothing
24--
25--
26--
27--
28--
29Engine oil temperature measurementAnalogue
30Child safety and deadlocking relay output on right hand drive (C3 only)All or nothing
31--
32--
33--
34--
35BODY VAN 2 DATA/B signal-
36Automatic gearbox parking position input (C3 only)All or nothing
37BODY VAN 2 DATA signal-
38Automatic gearbox sport position input (C3 only)All or nothing
39Automatic gearbox snow position input (C3 only)All or nothing
40--
2.2. Connector EA
-waysignalNature of signal
1Protected supply (first wire)-
2Electronic earth for the alarm-
3--
4BODY VAN 2 DATA signal (alarm)multiplexed
5BODY VAN 2 + supply-
6BODY VAN 2 DATA/B signal (alarm)multiplexed
2.3. Connector EH1
-waysignalNature of signal
1--
2--
3--
4Front LH door open switch inputAll or nothing
5Front RH door open switch inputAll or nothing
6--
7--
8Earth for measuring the outside air temperature-
9Child safety and deadlocking relay output on right hand drive (C3 only)All or nothing
10Rear windows deactivation relay output (C3 and C3 Pluriel only)All or nothing
11--
12--
13--
14--
15--
16--
17--
18Outside air temperature measuring inputAnalogue
19ESP activation/deactivation dashboard warning lamp output (ESP)All or nothing
20Child safety activation/deactivation dashboard warning lamp output (C3 and C3 Pluriel only)All or nothing
21--
22Engine running information output for authorisation of triggering of heated seat (C3 and C2 only)All or nothing
23BODY VAN 2 DATA signal (rain sensor)multiplexed
24--
25Interior lamp lighting inputAll or nothing
26BODY VAN 2 DATA/B signal (rain sensor)multiplexed
27Front LH door unlocking inputAll or nothing
28BODY VAN 1 DATA signal (switching module under the steering wheel)multiplexed
29Front RH door unlocking inputAll or nothing
30BODY VAN 1 DATA signal (switching module under the steering wheel)multiplexed
31Rear RH door child lock input (C3 only)-
32Courtesy light lighting output-
33Rear RH door open switch inputAll or nothing
34Rear LH door open switch inputAll or nothing
35Parking brake inputAll or nothing
36Rear LH door child lock inputAll or nothing
37Driver’s seat belt input (L.H.D.)All or nothing
38BODY VAN 1 DATA/B signal (airbags ECU)multiplexed
39Driver’s seat belt input (R.H.D.)All or nothing
40BODY VAN 1 DATA signal (airbags ECU)multiplexed
2.4. Connector EH2
-waysignalNature of signal
1--
2Rear tailgate opening control output-
3Rear screen opening control output (C3 Pluriel only)-
4Boot light output-
5Child safety activation/deactivation output (C3 and C3 Pluriel only)All or nothing
6ESP activation/deactivation output (ESP)All or nothing
7--
8--
9Rear wiper park input (C3 and C2 only)All or nothing
10--
11--
12--
13--
14Rear screen opening control input (C3 Pluriel only)All or nothing
15--
16Rear tailgate status (open/closed) input (C3 and C2 only)All or nothing
17Rear tailgate opening control inputAll or nothing
18COMFORT VAN DATA signal (parking assistance ECU)multiplexed
19--
20COMFORT VAN DATA/B signal (parking assistance ECU)multiplexed
21--
22--
23--
24--
25--
26--
27--
28--
29--
30--
31--
32--
33--
34--
35--
36--
37--
38--
39--
40--
2.5. Connector PH1
-waysignalNature of signal
1LH stoplamp supply output-
2--
3COMFORT VAN supply (parking assistance ECU)-
4Rear foglamps output-
5Rear wiper supply output (C3 and C2 only)-
6--
7Reverse lamps output (reverse gear)-
8Protected distribution (second wire) (BAT_1)-
9Heated rear screen output?-
10RH stoplamp supply output-
11Rear RH sidelamp output-
12Accessories positive supply for the rear harness (C3 and C2 only)-
13Right-hand rear indicator output-
14Left-hand rear indicator output-
15Rear LH sidelamp output-
16BAT+ supply-
2.6. Connector PH2
-waysignalNature of signal
1Accessories positive supply on the front harness-
2Protected distribution (third wire) (BAT_1)-
3--
4BODY VAN 1 + supply (airbags ECU)-
5--
6--
7Demisting rear view mirrors output-
8Rear push operation electric windows supply (C3 and C3 Pluriel only)-
9Front push operation electric windows supply-
10Sunroof supply (C3 and C2 only)+12V
11BODY VAN 2 + supply (rain/sunlight sensor)-
12--
13Door locking output-
14Unprotected ignition positive supply (for air bag ECU)-
15Door unlocking output-
16Child safety control output (L.H.D.). Deadlocking motors supply output (R.H.D.)-
2.7. Connector PP
-waysignalNature of signal
1Brake pedal switch information input (stop)-
2Ignition plus supply-
3BODY VAN 1 + supply (engine relay unit)-
4--
5Reverse gear information input-
6Electronic earth-
7Air conditioning compressor output-
8Power earth-
9--
10Protected distribution (second wire) (BAT_1)-
11Protected distribution (sixth wire) (BAT_2)-
12Protected distribution (fourth wire) (BAT_1)-
13Front LH sidelamp output-
14--
15Front RH sidelamp output-
16BODY VAN 1 + supply (switching module under the steering wheel)-
2.8. Connector PB
-waysignalNature of signal
1Protected distribution (fifth wire) (BAT_1)-
2--
3--
4Accessories positive supply for the dashboard-
5--
6VAN + supply for the dashboard-
7Button lighting output on the dashboard harness-
8COMFORT VAN DATA signal (instrument panel)-
9System status LED output-
10COMFORT VAN DATA/B signal (instrument panel)-
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My Name: C3CAR

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Joined: Wed May 04, 2011 10:01 am
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
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3. Service
DomainsPrinciples of operationDetails of the functions
Multiplexed structureElectrical supplyStandby / reawakening of the networks. Power save mode. Increase in load/load reduction of the electrical network. Automatic cut-off of the consumer functions (economy mode)
Multiplexed structureGateway between the multiplexed networks. Gateway between the sensors and the networks. Distribution of electrical supplies
Lighting - signallingInterior lightingControl of timed illumination / extinction of the front and rear interior lamps. Flashing of the courtesy light if the door is open and with the vehicle moving
Exterior lighting / signallingAutomatic lighting of hazard warning light on high deceleration. Vehicle location
Driving assistanceWash/wipeAutomatic wiping in the event of rain (vehicles fitted with rain sensor). Intermittent wiping linked to vehicle speed (vehicles not fitted with rain sensor)
Rear viewElectric adjustment of mirrors. Electric foldback and deployment. Heated exterior mirror
De-icingPossible heated rear screen load shedding. De-icing of the rear view mirrors linked to deicing of the rear screen
Overspeed controlOverspeed alert management with threshold programmable by the driver and memorisation of the overspeed threshold. Processing of the excess speed alert with threshold pre-programmed by the diagnostic equipment
speed controlSending of commands from the user to the engine ECU
Information to the driverInstrument panelMileage memorisation. Passenger compartment equipment brightness rheostat. Separate trip computer in the instrument panel for vehicles equipped with clock or multifunction screen type A
Aid to navigation / geographical locationTransmission of the distance travelled and vehicle speed information to navigation ECU (C3 only)
Parking assistanceRear obstacle detection
Confortheating/ventilationRequest to engage air conditioning compressor. Air conditioning compressor control. Evaporator icing safety . Air con pressure safety. Safety using engine speed. Broadcasting of coolant temperature information
Electric windows. sunroofFront electric windows with anti-pinch (C3 and C2 only). Rear electric windows deactivated if child safety active (C3 Pluriel only). Central closing using the remote control
Audio systemAuthentication of radio using VIN code. Radio volume linked to vehicle speed. Transmission of information from the audio system for message display management on the multifunction screen
Steering lockDoor managementLocking and unlocking of the doors using the key (on the driver’s and/or passenger’s "transmitter" locks) or using the remote control. Automatic relocking of doors and tailgate after 30 seconds if no door opened. Automatic locking (at 10 mph) of the tailgate (C3 and C2 vehicles). Automatic locking (at 10 mph) of the rear screen (C3 Pluriel only). Door open detection. Unlocking in the event of an impact
Anti-theft alarm systemPerimeter protection. Volumetric protection deactivated if folding roof open (C3 Pluriel only)
immobiliserIgnition key recognition. Unlocking of the engine ECU
Protection and safety systemsAirbagsCut-off of the supply to the fuel pump and the additional heater pump in the event of an impact. LPG reservoir electrovalve stop
Emergency callAutomatic emergency call in the event of a collision (airbags triggered) only for vehicles equipped with (RT3) radiotelephone level "
Power unitCooling systemEngine water temperature warning
User avatar
My Name: C3CAR

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Posts: 2658
Joined: Wed May 04, 2011 10:01 am
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
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Citroen C3 Central Locking BSI Repair topic to read if you have BSI relay central locking issues.
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Model: C3 Pluriel - with or without roof
Year: 2003 (53)
Engine Size: 1.6 (16v)
Fuel Type: Petrol
Mileage: 90000
Trim Level: VTR+
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: ET3 16-valve (90 PS)
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C3 Master
Posts: 253
Joined: Mon Dec 18, 2017 12:10 am
Model: C3 Pluriel - with or without roof
Year: 2003 (53)
Engine Size: 1.6 (16v)
Fuel Type: Petrol
Mileage: 90000
Trim Level: VTR+
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: ET3 16-valve (90 PS)
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If your BSI turns out to be beyond repair then all is not lost. It is possible to replace all the main components as a paired kit to ensire compatability and IMMO pass (immobilisation pass - engine starts). Have a look at this topic: Swapping/changing Citroen C3 ECU's for an idea of what is involved the ECU/KEYS/BSI kit swap.
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