Hi,

I have a problem with remote locking/unlocing not working on my 2005 R53, since I had to jump start it yesterday due to flat car battery (12v LAB - not the keyfob battery). I'm struggling to find answers on Google because as soon as the word battery is included, search results all relate to the keyfob battery, and not the 12v LAB. If anyone has overecome a similar issue, or has a suggestion, please let me know. Thanks.

Here is the sequence of events and what I've tried:

1. Remote locking was working fine - that's how I was able to get in and try starting the car ;-)
2. Tried to start the engine but the car battery was flat (instrument lights come on with the ignotion, then go out when trying to start - engine does not turn over)
3. Attached another 12V LAB to the car battery, with jump leads, and started the engine fine.
4. Drove arond 10 miles to destination and found the car wouldn't lock remotely (so manually locked)
5. Returned to car, and it wouldn't remotely unlock (so unlocked manually)
6. Drove home and had the same remote locking/unlocking problems
7. Left the car battery on charge overnight.
8. In the morning, the remote locking/unlocking still wouldn't work.
9. Tried the key pairing sequences (I found 2 versions on Mini Mania: https://www.minimania.com/Reprogram_...Keys_R50_52_53).
10. At the end of each pairing attempt, I think the doors should lock and unlock to confirm pairing. They do not do this (I tried quite a few times). However, at the end of each pairin sequence a speaker (behind the instruments?) plays a "cheerful" little tune, as if to indicate pairing has worked.
11. Both keyfobs seem to be transmitting fine as (in addition to illiciting the aferementioned tune playing after pairing) my RF remote tester indicates signal received for all buttons, so I truly don't think it's a keyfob battery issue.

It seems odd the issue arose after having to jump start the car. I'm wondering if this caused a fuse or relay to fail, but that's only a guess. I have no real idea, at thsi time, what the cause or solution might be. Any help would be graetfully received.

Regards....

 

I figured out the problem and am posting this reply for the benefit of anyone who has a similar issue:

Bearing in mind the central locking worked manually (both with the key and internal switch), I assumed this may be due to a fuse or relay issue.

After looking at the wiring diagram, which showed no separate fuses or relays for the remote receiver (I.E. manual and remote locking/unlocking share the same fuses & relays), it seemed most likely hte issue was with the receiver.

...but where to find the receiver?

Turns out, as I have an aut dimming rear view mirror, the receiver is simply a PCB, stored inside the mirror housing. After removing the mirror (plenty tips on the internet for that) and prising off the front cover (using a plastic "spludger" - not a sharp screwdriver!!!), I found the board and the probable reason for it not working: the mirror housing had quite a bit of water in it, and the board was showing signs or corrosion (and possible deterioration or a couple of chip pins). Only the UNDERSIDE was damage - the top, which is what you see when you open the mirror, looked fine! So, it seems the water was only just deep enough to affect the undeside of the board, while leaving the top undamaged. See pics (topsde, damaged underside and cleaned underside).

Even after cleaning, the unit is unresponsive. I'll try we working the board (with an SMD re-work station), but I'm guessing I need to find a new one. The only source I've found to date is whole mirror units from scrapped vehicles - I'd prefer just a replacement board.

So, now I have THREE jobs:

1. Source a compatible receiver: install & test.
2. Find out how on Earth the water got in there. This is NOT a convertible and the antenna gasket (at the opposite end of the roof) seem fine, yet the water poured out of the mirror housing (all over the radio) and the sound-proofinf behind the headliner is very wet
3. Take out the headliner and try to dry everything behind it before things start going mouldy