Need some help for CAN-BUS multiplex for Citroen C5R 2007 2.0 HDI

[AnthonyKnight]

How many termination resistors does Citroen c5r have because i read 123 ohms at obd port between can-h and can-l, and if one is in the BSI, but where is the other termination resistor on my car? Here is a full diagram of my can network in the image, car is no start no crank no comunication with both lexia and other diagnostic tools to all ecus that are connected to the high speed can network, lexia shows dialogue with ecu and abs but when i enter it i can't communicate both with Injection and Automatic transmition but in global test it gives dialog with ? on fault on because they have a special L line from the OBD connector but i can't acces in both of them. all on van network is fine and working immobilizer is correct recognized, i need help from someone good in multiplex for citroens please, When i unplug all ecus and measure the resistance it stays 123 ohms except for the electronic stearing pump ecu because it is very hard to get to i don't know how to acces the connector to disconect it and measure again, servo pump working constantly on ignition on but i assume that is a safety feature and a rellay in the BSM or ECU modul is clicking on 4-5 second interval at ignition on plus on each click there is a silent buzzing sound near the injectors that reduces slowley and than repeats again after the rellay click again on same interval fuel pump works on ignition on and when i want to start the car only a click in the bsI is present ABS warning hand brake warning light on dash and dipped light beam green light flashes, navi shows braking unit faulty, suspension faulty tire preasure not monitored directional lamps faulty. I tried replacing 2 other ABS units still same tried ECU BSI IMO combo still no crank still no comunication with same ecus only odometar millage change to the donor unit. Is the other 120ohm termination resistor in the ABS ?

[wheeler]

The end of line termination resistors are in the BSI & the injection ECU

[AnthonyKnight]

I measured directly on the the injection ecu and the bsi pins for can-h and can low and i get exactly 120 ohms so that means they both are present i measured on the wireing harnes of ecu i get 120ohms but when i reconect it to the car and measure at obd i still get 120ohms and i should read 60 is there by any chance the obd por has its own 120ohm resistor or i should dive back in to tracng wiring issue from bsi connectors to elswhere ?

[wheeler]

If you are getting 120 ohms each on the terminals of the CAN H & L then sounds like you have a break in the CAN.
I would start somewhere in the middle like the ABS unit & do the measurement on each set of CAN lines with the ABS unit unplugged. I expect one side will be open circuit. You will then know if its in the direction of the BSI or injection ECU

[AnthonyKnight]

I measured the who can network for continuity from ecu to abs from abs to suspension from suspension to bsi from bsi to obd port and lines are intact checked the ecu and bsi directly on the pint they bote give good reading 120 ohms but when all connected battery out i read 120ohms even with ignition on 120 ohms, voltage on can-h and can low with ignition on is 2.5v on both and 0.0 between them, the only change i see is of 0.1 volts each time the same relay clicks in the bsm in 4-5 second interval, also i see voltage fluctations on the battery terminals of 0.3 to 0.4 volt each time the relay clicks on the interval time, the only thing i can't disconect from the network is the electronic stearing pump i just don't have acess to its jacks but acording to the diagrams it is conected to the suspension module via high sppeed can line and one more thing when i measure the voltages on the connector of the suspension pump for can high i get 0.75 volt and for can-low 4.75 volts i just cant figure out if the fault is in the bsI or in the stearing pump that activates on ignition on with loud whining noise but considering i replaced the whole bsi ecu immobilizer combo together and get the same issues altho replacement was number h-05 mine bsi is h-02 jonson controls i would assume it might be the stearing pump or i don't know what else to look for, also the orange BITRON conector clicks one time when i connect the battery to the car and when seen with thermal camera it gets hot on ignition on but i don't know its purpose and what does he do somewhere on internet someone says it is suspension supply others cooling fan relay so i am litteraly stuck now don't know in what direction to look for the fault. also original abs ecu unit have good continuity on the that comes and goes to ecu plus chips work under power load with ignition on

[AnthonyKnight]

Maybe is damaged one can transiver in the BSI and sends wrong voltages acros the CAN network ? and the resistor would be fine but that still doesn't explain the 120 ohms measurment when it should be 60ohms and i literaly tested the whole can networ for continuity

[wheeler]

Do you have the correct diagram? Something jumping out is a C5R does not have VAN, its all full CAN

[AnthonyKnight]

Car fixed after 3 year seeting in the garage electric servo was bringing the whole CAN network down, after disconecting the servo pump from the network comunication on all systems returned delleted the codes with the Mucar diagnostics, started without a blink, engine runs like a charm can't belive the old citroen 2.0hdi engines integrity they are like tank. Thank you so much for the help now i have a lot of work replacing new stearing pump and bleeding the brakes because i removed the ABS unit before. I don't have the words to describe how happy i am after seeing my old citroen run it brings tears to my eyes i currently drive chevrolet it is not comparible to the citroen in no way even tho its much older

[AnthonyKnight]

My C5 have VAN plus LIN and Low speed Can network on certain ecus

[wheeler]

Thats great news, what do you mean by electric servo?
If its a facelift C5 after 2005 there is no VAN, its a full CAN system (but does have a small LIN too)
Has high speed ,low speed & intersystems CAN. VAN was removed after the Mk1 C5

[AnthonyKnight]

I meant servo stearing pump because it is electroninc not belt driven. Well the VAN might be error in the diagrams those once were from Auto Data the SeDre diagrams were a bit of mess to plus not complete for my car.

[wurlycorner]

Brilliant news that you got this sorted, well done.

Wheeler's knowledge on these kind of things is fab.

[AnthonyKnight]

Yes, the only problem is i cant find a replacement part in my country, and that is a bit anoying. Dound one he asks for 250 euro, and he is mad if he thinks i will oay him that much for 20 year old part that needs to hold up to 100 bar of preasure