Mk 1 C5 BSI

[Stempy]

Are BSI units interchangable or are they coded for a particular vehicle. The reason I ask is that I have a spare one from another V6 C5 and wondered if I could straight swap it as a fault finding excersize?

[Mandrake]

I don't know the answer for certain, but given that the BSI in a C5 replaces the CPH in a S2 Xantia (and includes a few additional functions) I would say chances are very strong that the engine ECU and BSI are coded together.

What fault are you trying to troubleshoot ?

[Ben82]

In short (from the BSI/ECM pairing document).

CAUTION : BSIs, ECMs and keys are allocated to a vehicle and therefore cannot be exchanged between two vehicles.

[Stempy]

Nothing major but heated seats dont work and I've traced it as far as a lack of voltage on a pin eminating from the BSI and also rear windows are intermittent. Having pulled the spare BSI apart I have found that it consists of two separate PCB's, one is the digital board and the other has the fuse sockets and several print mounted relays, any of which may be duff. Not having a schematic of the BSI internals I have no idea which does what. I could swap the relay board complete but it is double sided print and soldered to the digital PCB with a fair number of links.

A straight swap would have been the easy option but if thats not on then I may have to have a rethink with regard to relay identification. It might be a case of trying to trace the print on the PCB.