Key Remote Locking Not Working

[Sol]

Ah ok, that "fuse box" is actually not a conventional fuse box but is the BSI itself (it has fuses onboard for the things it controls - basically anything not attached to the engine)

It's possible you have done something there so well worth a look. Make sure you haven't overloaded a fuse that is meant for something else - and as pointed out by Rasputin the oem stereo is all canbus and doesn't have a permanent feed, all systems on a Berlingo shut down after 20 mins to preserve battery so there are no live feeds visible once that time has passed. You need to restart the engine and check the stereo wiring again with the engine running, to find the real 12v feed (only on when running, there are no feeds that are always on inside the cabin)

Better to use one of the engine bay positive feeds on the battery connection unit or the engine bay fuse box as it is always on. Fusing it down of course to suit or use a piggyback.

[Gryffindor]

Zion, that's all fascinating detail. I did spot a chip in the MFD which seems to be related to the remote key system but never got round to pulling a com2000 apart.

Could it be that the antenna in the com2000 is connected to the chip in the MFD, and that in turn goes to the BSI? If so, then because MFDs can be swapped without such issues, then it would also bode well for swapping com2000s.

Well done!

[Sol]

Could well be mate, I do have MFD schematics somewhere if I put my VM with ServiceBox back on a laptop. Downside is it's not VIN specific - I have to search by model as my ServiceBox is offline only if you catch my drift.

The MFD could well be the next part, what was the chip? I've dug and it does confirm the antenna itself is on the comm2000 board which makes sense as it's ideally placed to communicate with the key. Where does the ignition barrel loop plug into for example.....the comm2000 (can we start calling it the Com2K lol) - I still expect some coding between different comm2000 units at the BSI due only to functionality, like variable speed wipers or cruise stalk capabilities, but for the same generation of vehicle then all Com2K units I think will be swappable. Remember too every item even the MFD will have a Canbus transceiver chip. Also an EPROM to contain it's slave ID etc. It's very like Modbus which we use on industrial machinery comms. And CAN looks like RS485....

[Gryffindor]

Com2K is fine by me, but since we now know it has an antenna, how about Y2K? That'll wind up a few people! Not far off in terms of year either.

On the chip in the MFD, scroll down in this post...
https://www.berlingoforum.com/thread-201...#pid127299
...to the 3rd para after the four pics, which starts "As for my guess..." which refers to a guess written in the 4th photo.

Looks like we need someone with a spare C2K to give it a forensic once-over and report findings. I don't have a spare at the mo.

One point - in the above post I noted that the MFD only uses 4 or 5 of its connector pins, 4 being presumably used for the vanbus. So how does the C2K antenna connect to the MFD, if it does? Or does it connect to a chip in the C2K which then speaks to this MFD chip via vanbus? That might make better sense.

[Sol]

The TSS461C will be how the MFD gets its data, over Vanbus I expect. I don't think the MFD plays a part in the key stuff, but the Citroen schematics state the antenna for locking is on the C2K board though I've not studied a real one to work out what the chips are. Could be a printed track at 1/16 wave etc, in the shape of an antenna. 433mhz is pretty short wavelength at 69cm so 4cm - possibly built in to the track etch.

[Gryffindor]

Yes, here's an example: a screenshot from a recent Big Clive YT vid.

   

This is a much enlarged photo of the PCB inside a wall-mounted wifi light switch. You can see the white switch to the left. It's advertised as operating at either 433mHz or 315mHz, and Big Clive is saying that the solder pads he's pointing to probably allow the antenna to be lengthened, lowering the frequency.

433 seems to be becoming a standard for all sorts of gadgets in this region.