OK, got a bit of a fundamental issue....
Earlier this week, the EML came on; fault code was P0341 - camshaft position sensor. Car was running OK, so I cleared the code to see if it returned - which it did.
I continued to use the car, but ordered a replacement camshaft sensor. In the interim, I noticed that when first turning on the ignition, "Parking Brake" would occasionally flash up, along with "Electronic Immobiliser Fault". The car would turn over, but not fire. Switching off and on again fixed it.
This morning (Saturday), I picked up the new sensor, fitted it, cleared all the fault codes, and for good measure, carried out the battery disconnect procedure to reset the BSi.
First trip out, it was fine; 2nd trip out (was at Tesco), EML light came on, along with the "Parking Brake" message and the "Electronic Immobilser Fault" message. I switched off, switched on and it was fine, although the EML light remained on.
When I got home, I checked the fault code, and got two different ones: P0135 and P0138 (from memory) - indicating oxygen sensors. Something was clearly amiss, so I decided to check the BSi connections (following the battery disconnect procedure).
Despite the little waterproof jacket around the connectors, water had got in to one of them (one nearest the front of the engine) - blue gunk and corrosion on the pins and in the plug. I removed the BSi, cleaned it up as best I could, and replaced it. Now it won't start at all - "Parking Brake" and "Engine Immobiliser Fault". Turns over, but doesn't fire.
The ECU is currently sitting indoors, close to a radiator, where I'm hoping it will dry out. I'll have a look at the plug later as well.
Worse case scenario is a new BSi - well, not a new one, but a used one. Car is 10 years old and not worth much, and I know replacement BSi units from Citroen are hundreds.
The basic searching I have done (eBay) indicates BSi units are readily available, although I assume I'll have to make sure it's compatible with my model. The other assumption I have is that it won't be a straight-swap - Citroen will have to re-programme it.
Anything else I need to think about? I've looked on the FAQs, and you can't search for BSi on the forum search because it's < 4 characters
Any advice welcome!
Edited by Bornagainbiker, 01 February 2014 - 02:01 PM.