Citroen C5 no start, no cranking, no clicking starter

[AnthonyKnight]

Help multiplex guys, I have a non start citroen C5 2.0 Hdi FAP 136 automatic 2006 , no cranking and no clicking on the starter, when turning the key to start the engine nothing happens only constant buzzing noise coming either from the alternator or from the suspension pump and relay that clicks every 5 seconds in the BSM, brake interlock not working, the imobilizer is ok because when i leave the key in the lock and open the door it knows that the key is still in the lock and gives a warning, i checked the fuses on the BSI and other fuses inside they are ok, checked the maxi fuses and the fuses on the BSM they are fine, battery is fully charged, i tried BSI reset and still the same errors return, on the navigation screen it shows many warnings: STOP Brake system faulty, !Aribag(s) or pretensioner seat belt faulty, !Tyre presure not monitored, !Directional headlights faulty !Suspension faulty, etc, now i know this faults are chained to the main cause of the fault but i can't figure out what could the main fault be,
i did a Golbal test scan with Lexia and i have no comunication with the engine ECU in the others there are the same codes repeating it self i will upload some pictures if you can please help me solve this issue thank you,

[wheeler]

First question has your Lexia ever spoke to the injection ECU previously? Fake interfaces are known to be hit and miss with Full CAN systems.
If you disconnect the MAF & switch the ignition on do you have a 5v supply at any of the terminals?
What is the history of the fault? Was it working ok one day then not the next? Has it been sitting unused for a while? Did it cut out whilst driving?

[wheeler]

the imobilizer is ok because when i leave the key in the lock and open the door it knows that the key is still in the lock and gives a warning

P.S. thats not a good indicator that the immobiliser is working ok, the system only needs to see a transponder chip, not necessarily one that is programmed to that car to trigger the key left in warnings. Anyway the immobiliser doesn’t inhibit the starter motor on this car.

[RichardW]

Is the battery actually OK? Reported voltages look suspiciously low in some of those shots.... Does it maintain over 12V when you switch on the ignition?

[Kayso]

Hello My cars c5 2007,same problem my cars..! Problem to solve your cars ? Do you help me ?

[Dormouse]

Battery voltage readings definitely suspicious - either poor battery or poor feed connections.

therefore not surprising you have the spread of odd faults

[Kayso]

Batery new ! Braking system faulty,parking lamp and Stop lamp..no start

[Kayso]

Batery new ! Braking system faulty,parking lamp and Stop lamp..no start

[admiral51]

Think the latest posts are a cry for for help added to an existing old thread.
Without any codes etc and not knowing the 2007 C5 was just thinking that maybe the BSM could be at fault throwing up faults that make no sense to starting the car ?

[Kayso]

The problem continues,brake oil ok,battery new change ok,ecu change but unsuccessful,insuranca control ok,3 d?t d?t d?t stop no start..obd device no signal no connect

[Kayso]

With experience ?

[Doo]

Batery new ! Braking system faulty,parking lamp and Stop lamp..no start

I believe these systems are all connected. Wasn't there a recall for the ABS pump due to corrosion in the multi-plug?

FIRST thing, check any fuse in the ABS circuit. Then relay (noid) connection. Then look for bad earth ( - negative strap) body to battery various connections and finally go to the ABS pump/distributor & check the multi plug where the wires go to the pump/distributor.

[Kayso]

[Kayso]

Abs beyni,entegre

[Doo]

That is one fried chip

Looks to have been VERY hot or voltage spike! Before replacing you will HAVE to find the cause! Test ALL connections. Make sure the multi-plug to the ABS module isn't damaged because that looks like a few pins/wires have short circuited and cause a major spike or short circuit....