Hi everyone, thanks for looking & season's greetings from the UK. Unfortunately I am having a bit of trouble with the Mini at the worst time of year for this kind of thing

Christmas day, I looked out of the window to see the Mini (03 MCS) had decided to open the windows and sunroof, and unlock itself. Whenever I try to lock the car (any method), it just unlocks again right away, and does the comfort opening process of opening the windows and s/roof as if the keyfob/toggle were being held to unlock. When driving it tries to lock at 12mph but unlocks etc again, then stays unlocked for the journey.
Both locks go up and down when it attempts to lock, all door handles work normally.

I have done some searching and found some similar problems and possible solutions. Battery (of the car) is fine and is displaying the green led, car starts and drives as normal and a long drive did not cure anything.
Keyfob is not causing the unlocking, took it out of range and problem persists, it also attempts to lock the car remotely just fine.
I looked for the BC1 and it has the revised plastic cover, and I have not had any issues other than (seemingly) relating to the locks, so I do not think this is the most likely culprit, also the problem did not occur after rain or washing.

I would like to check the door lock sensors first to eliminate those, as it seems there is a constant unlock signal being applied from somewhere. The lock mechanisms seem mechanically fine, both lock properly from the door buttons (with battery disconnected - only safe way I can think to leave the car ) and open from inside/outside handles as they should.
Is it possible to test the door sensors individually by removing fuses or disconnecting cables?
Or does anybody have a better idea of what may be up?

Thanks very much for any help or advice

 

Took out the power locking fuse - locks no longer unlock themselves (obviously), but windows and roof still open themselves :( Not sure if pulling the central locking fuse would take power away from the entire lock assembly though or whether the door lock sensors still have power. Perhaps the lock sensor is still to blame.

When battery got reconnected, power to CD changer kept cycling (can hear motor inside it) as though circuit was constantly being broken/reconnected. Locks kept flicking too (fuse was back in). Makes me wonder if a ground point is failing, perhaps one of the ones in the rear (rear clusters seem to leak commonly?), and if perhaps these things are on the same or linked power circuit perhaps that could be what is causing the fault?
Unfortunately I'm no electrician, so any advice on where to find these grounds, or if I'm talking nonsense in general would be appreciated.

Thanks again

 

I checked a few things over today.

No signs of water ingress around rear door/brake lights, sunroof or under the bonnet/around headlights electrics.
Couldn't get the panel off to look properly at the BC1 unit, but peered in and probed for any signs or damp, but it all seems dry too - there was very fine and dry covering of dust on the plastic cover, so it doesn't seem to have ever been dripped on. Felt under the carpet there and that was dry, no hint of condensation even.
I would like to properly check this unit, so if anyone can advise any special tips for getting the footwell trim panel out, please tell

Then tried different combinations of window/roof/power locking fuses, but the problem persists in all cases. I also tested all the lights which responded normally, although I didn't realise the rear licence plate lights were linked to the power locking circuit (no fuse = no lights), or that the 3rd brake light is on the same circuit as the sunroof (again, no fuse = no 3rd brake light).
I take it that is correct behaviour for these circuits though?

All other electrics work as normal, and the car runs with no problem and doesn't put up any error codes. Door locks and boot handle work as normal apart from the constant unlocking issue, that is to say the actuators are activating the door pins normally (they go up and down properly).
Similarly there are no problems with the window or sunroof opening, apart from all opening due to the comfort opening feature.


...which all leads me to think it must be one of the door locks is causing issue, there must be a sensor/switch in the lock unit that triggers the central locking when the key is turned in the door, and also triggers the comfort opening when held in the 'unlock' position. This getting wet or failing in the 'open' position would surely cause the same symptoms, so I guess I have to be brave and pull the door card off and have a look at that tomorrow.


Still can't believe nobody else has had and fixed this problem themself though?