FUBARED BSI?

[StvC]

Hi, I'm sure this is a common ask, but would take me ages to sift through all the BSI related search results.

Basically my 2009 C5 HDI140 VTR+ won't start, or, more often than not, doesn't start. Sometimes it starts but will throw out the power steering when I go over a bump. Obviously I'd deduced it was likely an electrical fault, maybe ECU/Fusebox fault/dry-joint/broken connection etc. But the RAC man came out and mentioned the BSI which, being honest I'd never heard of. He couldn't get any reading on his scanner which I think prompted this diagnosis.

Does the FCF hive mind agree with this diagnosis and what's the best way of getting it confirmed/fixed...there are companies online offering BSI repairs or resets etc. but wasn't sure how reliable these companies will be but also figured there will be a few trusted names that have become known to this forum over the years. I'm in the North East (sorry if my profile still shows me as Herefordshire, I moved).

TIA.

[RichardW]

It's quite unusual for the BSI to fail, and replacing it is neither cheap nor easy. I would want to get some better diagnostics before jumping in! A dodgy or loose connection around the battery seems more likely.

[GiveMeABreak]

The BSI is the master controlling computer in the vehicle responsible for most things and is rather expensive to replace, so I would get some kind of confirmation before doing anything with this - and don't forget it can't just be replaced without configuration from the servers. BSIs are matched to the engine ECU once paired.

I would suggest it is very unusual or unlikely not to get anything from a diagnostic from the BSI - as if it simply stopped working, most systems would not work. I would suggest getting it properly diagnosed with Diagbox, but if that still isn't communicating with the BSI, then I'd be looking at the power supplies, fuses and connections to the BSI first of all in case a connector or fuse is bad or from the supplies management that provides the power to the BSI.

So really a decent auto electrician if you don't want to go to the dealer.

[StvC]

Whats diagbox sorry.

and yes it does seem entirely odd. Only the doors unlock which the rac guy said was the only system that is independent of the bsi, all other systems do not function. But the fact there is power to the doors rules out a battery issue in my mind.

I understood and google seems to imply that the BSI can be reprogrammed or 'wiped' to avoid the expense of replacement a bit like how you can send ECUs off for remaps etc I assume.

[GiveMeABreak]

Diagbox is the software used with a Lexia 3 VCI interface by PSA on their vehicles for all diagnostic and programming operations. Basically a dealer-level tool.

Yes they can be virginised - but also have to be a) reprogrammed afterwards which is quite an extensive job to ensure the correct engine, ABS / ESP, gearbox, Telematics and basically all the other myriad of factory-fitted and optional equipment as fitted at the factory is correctly programmed in. But it will also need pairing to the engine ECU and the transponder fobs will need re-pairing too.

I don't totally agree with the RAC man. The BSI is very much integrated with the central locking system. It's what authorises the opening and locking of the doors via the fobs and controls the deadlocking. You can of course use the key in the lock to unlock the car of course, but that will set the alarm off unless you switch the ignition on to stop it. Starting the car won't happen without the BSI as it needs to handshake with the transponder and the ECU.

I still think it needs further investigation.

[StvC]

Thanks that's interesting, just for reference the fob very much still works and we do have some lights on the dash, depending on what way the malfunction manifests itself so it has to be a scrambled something.

Is there any independent PSA specialists the forum recommends (in the North East ideally) or is a Citroen dealer my only chance. Last time I rang one for a quote they wanted over £100 an hour labour.

[GiveMeABreak]

That's correct, main dealer diagnostics are about £100-120 an hour. You're supposed to be paying for the training and expertise of the technicians. So unless you can find a specialist that knows what they're doing, then you could end up paying far more than that by the time you've spent a lot on unnecessary parts and gone from garage to garage.

They may be able to run tests to determine if it is the BSI or the electrical connections / supply to it. It's a difficult choice on this one as it's not mechanical, but more of an electrical issue I suspect.