CitroenCrazy wrote: 02 Feb 2021, 13:44
Thanks guys, I really appreciate the time you've taken to share your experience and expertise.
James, although I haven't tried the procedure exactly as you outlned, it's more or less covered by the 7 step process in my original post. It might just be me, but I couldn't get that to work in this case.
Marc, I understand your logic, and I agree that the issue lies between the "failed" fob and the BSI, but I'm confident the fob is working, at least in the first instance - see below.
ozvtr I'm slightly confused; I think you and I may be using terminology differently. In my mind at least, the RFID chip is the wee module down by the key blade; mine's labelled Philips PCF 7936AS. I've learned a lot about these, but they're only used for the immobiliser, so can be discounted for now.
On the RCL board (7337 3067C), there's only a microcontroller and an oscillator that sets the transmission frequency. I haven't managed to find any technical documents covering these. So far, I've assumed they are not configurable after they leave the factory and thus pairing one with a car requires instructing the BSI to accept the code that's transmitted, but that may be a gross oversimplification.
If you'll permit me, I'll restate where I am, stripping out all but the essentials.
The only issue I have is associated with the RF central locking (RCL), all other aspects of the key and key programming are ok.
RCL works with one key but not the other.
Both keys came with the car. I wish I could be sure whether or not the RCL has ever worked on the problem key, but the car was my mother's and one key was kept as a spare, so alas, I can't be sure whether the problem is relatively new or long standing.
I am sure the non-working RCL module is transmitting on the correct frequency, so the buttons and the battery are ok.
The reason I can say this with confidence is that, firstly, I can see a response on an RF spectrum analyser (a slightly grand way of describing some open source software and a £15 USB module) but more importantly, if I use the BSI parameter measuring page in Lexia, a button press is registered, but it's shown as an unidentified message. It's transient, and I didn't manage to catch it in a screenshot, but imagine the highlighted section below blinking from No to Yes and back again as the button is pressed.
The bit that I'm most curious about is the BSI status screen that shows only one RCL module programmed. Somehow, I need to make the lower field read 2
If I went to a dealer and said I've lost my spare key and need a new one, they would be able to produce one for me. Obviously the price would be a significant proportion of the value of a 2003 C3 these days, which is why I don't propose to do it, but ultimately, the question comes down to how they would configure a new RCL fob to work with the car, and is that course of action available to anyone with a Lexia ?
At one point, while I was searching around BSI-related screens in Lexia, I found one called Guided Programming, which has this interesting line:
This is a configurable field, but when I dug deeper, it asked me for a 4 digit code and the one I used for programming the immobiliser (the one on the card that comes with a new car) didn't work, so I'm wondering whether there is a dealer ID that allows some parts of the cofiguration to be updated. In any case, to be of any use, we would have to convince ourselves that encoded within "0C1A" is the number of RF remotes........
The car's gone back to my mother for now, so I have a few days to formulate my next plan of attack
