Central Locking - odd, but repeated pattern

Hi folks
Just picked a 2006 1.6HDi Exclusive as a runabout - great little vehicle.

Odd fault with it.
When I get out of the car after a run, central locking from the keyfob works fine.
Leave the car for c. 20 mins and the only way to unlock the car is to use the key in the driver's door, at which point, the alarm fires up.

Close the door, and the fob works immediately, locking all doors remotely.

This is a repeating pattern.

Had the keyfob battery checked - all OK.

Any ideas??

Hi

Do you have the original Citroen fit radio?

Or any extra wiring near the radio ?

C3CAR wrote: ↑Tue Jul 30, 2019 8:40 pm Hi

Do you have the original Citroen fit radio?

Or any extra wiring near the radio ?

Thought I'd replied to this, but can't see the reply, so apols if this double-posts...

The radio is an after-market fit; haven't got the original unit.

No idea about the wiring. Looks like a standard harness, but I'm not 100% on that.

Take the incorrectly wired radio out and try the remote locking for a few days to see if it's fixed.

If it's fixed, the radio has been wired incorrectly, which is quite a common thing for people to get wrong on the C3.

You can try resetting the BSI. Remove the ignition key, close all the doors and raise the bonnet. Wait 60 seconds, remove the +ve terminal for 10 to 20 seconds, reconnect the terminal and wait 60 seconds. Try the fob. This will wipe date/time in the central display and pre-sets in the radio. If the radio is miss-wired and connected to the bus, this will also cause problems as C3Car said and you will need to remove it and check the wiring.
When you restart the system (disconnect/reconnect the battery) the BSI goes looking for what's on the buses (with Reg Varney, sorry, old joke). It takes stock of what it does and doesn't have. If the old radio is removed with power on, the bus controller gets confused because it is looking for a component that's not there...and it does crazy stuff. Removing the stock radio and the central locking playing up is a classic symptom.
Failing all that the only other way is to "remove" the radio from the bus by telling the BSI that it doesn't have one. This requires a LEXIA tool.

C3Car & Ozvtr, thanks for the responses.

Should've mentioned that a) I unplugged and removed the Sony radio as it's permanently stuck in demo mode and b) the battery was removed to be charged up, as the car lights were left on overnight the day I picked it up (the result of driving around for years in cars that have an 'auto' function ).

I've ordered a LEXIA tool and will give that a go, then report back.

Fingers crossed...
Thanks again for the help.