It's been over 2 weeks since I replaced the Rotary Latch module, and I've not had any false alarms since.
Unfortunately the memory card in my camera had a fit and I've had to format it, without being able to get the images off - so no images of the job - sorry. I have borrowed an image from another forum user, of the latch module inside the door. I've added numbers to it to correspond to stages of the job below.
Anyway, a write-up of how to do the job:
Rotary Latch replacement cost me £80 from dealer
part #:
Drivers side (UK): 51200556767
Passengers side (UK): 51200556770
Diagram of latch and associated parts:
RealOEM.com BMW R50 Cooper DOOR HANDLE FRONT/LOCK, SINGLE PARTS
Tools needed:
Torx driver set - sorry don't know the actual sizes
Small flat head screwdriver
Large flat head screwdriver (or better still a rigid, stainless steel kitchen knife from your cutlery draw)
Time to do job:
Took me 1.5 hours but this is because I had to find a suitable way to reattach one of the cables. I found the perfect way so job should really only take you 1 hour. If I had to do the job again, I reckon I could do it in 30mins.
I imagine a garage would charge anywhere between 1 and 1.5 hours but I've not had a quote for this...I'm sure others on the forum have though?
Remove the door-card:
First you need to carefully prise off the bezel around the tweeter and inner door handle. It's one piece and comes off easily using a small flat-head screwdriver.
There are 4 torx screws that need removing. You can see three of them but the forth is behind the small circular reflector. Carefully prise it off with a small, flat-head screwdriver to expose the 4th screw. If your first gen mini was built 04 onwards then another of the torx screws is hidden -
see here for instructions.
Now with a large flat-head screwdriver (or better still an old knife from your cutlery draw) you need to carefully prise the door card off. Wrap something around the screwdriver head or knife, to avoid damaging the paintwork - I used an old sock. The door card is clipped in all the way around the edges. I started at the bottom corner at the back of the door and worked my way along the bottom, to the front. A certain amount of force is needed to pop the studs out of the clips but not too much. Once you have done all the edges, you need to kind-of lift the card up, to clear the lock button and out, to disengage it from the clips that run along the window edge.
Now you have the door card off, you are ready to remove the faulty Rotary Latch module.
Have a good look at your new module to familiarise yourself.
Here's an image of the module in the passenger door (of course, could be opposite way around, depending on which door you are working on). Please note: The latch is partially obscured in photo, by the window mechanism (black vertical bar in photo).
Remove the Rotary Latch module
Firstly, reach inside the door frame and locate where the wiring loom connects to the unit - numbered
1 in the photo above. Disconnect the wiring loom from the bottom of the latch module - you need to squeeze the edges to disengage it.
Now you need to take out the metal rod that is your lock button. It's pushed into a round plastic clip type thing, its green in the photo and numbered
2. Push the rod backwards to unclip and then remove the rod.
There are two mechanical cables that need to be disconnected (very similar to the brake cables on a bike). One is for the external door handle, the other for the internal door handle. The external one runs down to the bottom of module - you need to unhook the end of it - numbered
3 in photo. Once unhooked, you need to thread it up and out of the plastic holder. The second one is slightly more fiddly, and
can't be seen in the photo. The module has a plastic flap that needs to be opened so you can gain access to the end of the 2nd cable to unhook it. The flap either hinges at the top or the bottom - my old module hinged at the bottom, the new one at the top! Best thing to do is undo the 3 torx screws that hold the module in place, located on the outside of the door edge. This will free the module up and you can manouvere it a bit to get at it and actually see the flap. Prise the flap open with your small flat-head screwdriver and then unhook the end of the cable.
Once you've removed the wiring harness and two cables, and removed the 3 torx screws from the outside edge of the door, that secure the module in place, you can pull the module out. It's a very tight squeeze - keep the module pointing in exactly the same direction as when it's screwed into the door and work it slowly past the black bar (window regulator). It really feels like the module won't fit past this but as long as you have it in the same orientation as when it's screwed in, then with a little wiggling it will make it through. Be prepared to scratch your knuckles up in the process!
Transfer hardware from old to new module
When you have it out, take a good look at where you have to reconnect the cables etc. You will need to transfer the white plastic clip that the first cable went through, over to the new module and also transfer the metal hook that the first cable attaches to - Its just one torx screw - numbered 3 in photo. Make sure the white plastic clip is the right way around.
Reattach cables and install new module
Next thing to do is reattach the 2nd cable. I wasted a lot of time on this part, trying to attach the cable with the module in place inside the door - it's near on impossible! It really needs to be done before you squeeze the module back in. You can do this by unscrewing the 3 screws that hold the inside door handle/tweeter in place and then unclipping it from the door. This will allow you to thread the cable through the door, giving you some slack, and you can pull the cable through and attach it to the module before squeezing the module back in. Make sure you keep the cable on the correct side of the window regulator, otherwise you will get tangled when putting everything back in - you'll see what I mean when you do the job. When pushing the module back into the door, make sure you have it in the correct orientation - the same direction as when screwed in. Slowly wiggle it past the window regulator. Pull the cable back through the door so you can reattach the handle/tweeter.
Now reattach the first cable and thread it through the plastic clip. It's a little bit fiddly - you might find it easier to screw the module back in first, although I managed it with the module free.
Once the two cables are attached and the module screwed in, make sure you snap close the plastic flap. Reconnect the wiring harness. Now reattach the rod for the lock button. It goes in at weird angles but you'll work it out. Make sure you push it into the clip properly - the clip spins round so you can align it easily.
Test thoroughly
Now test that both door handles actually work. Make sure you try them after locking and unlocking the car a few times. The plastic clip that holds one of the cables was getting caught up on the door frame (I put it on backwards by mistake) and therefore the unit wasnt unlocking properly.
Put door card back on
When you're 100% satisfied that it's all working properly you can put the door card back on. Drop it down over the lock button, clip it in along the window, then just push hard around all edges, to clip the studs back in. Then screw the 4 torx screws back in, clip the reflector and tweeter/door handle bezel back on, and you're done!
Good luck!