Citroen C3 Owners

Hi all ,I have done a number of ECU/ bsi swaps on cars I have had because the fuse that powers fuel pump ,ignition ect has no power . I have just been thinking is it the engine ECU that goes or the relay in the bsi its self . which relay is it in the bsi ? . I've just been thinking about this as I probably have 6 complete sets sat in my workshop that I don't really want to throw away ,if it is just a case of unsoldering a relay from the bsi and fitting a new one . any thoughts ? . many thanks dean

Bogwoppit32 wrote:Hi all ,I have done a number of ECU/ bsi swaps on cars I have had because the fuse that powers fuel pump ,ignition ect has no power . I have just been thinking is it the engine ECU that goes or the relay in the bsi its self . which relay is it in the bsi ? . I've just been thinking about this as I probably have 6 complete sets sat in my workshop that I don't really want to throw away ,if it is just a case of unsoldering a relay from the bsi and fitting a new one . any thoughts ? . many thanks dean

Hi dean, you could just open up a BSI and test each relay and see what works and what doesn't. When you have found a bad relay in one, then you can go straight for that on the others..? If you don't find any parts in the BSI that you can repair, then you know its a part in the ECU or a part in the BSI you can't repair.

I am not aware of any BSI diagrams, but if you have one open on the bench can you follow the circuit from the fuse that powers the circuit and find the output pin that runs the circuit that caused a problem?

As you have found, its quicker to swap the whole lot (ECU, BSI and the KEY)


A look inside the BSI citroen-c3-tips/bsi-the-inside-story-t440.html