Well,

2005 MCS 90K+

Both of my key fobs have "petered out". Neither of them will lock or unlock the doors. I read many a threads recommending to "reset or re-program" the key by starting, remove key, press unlock....blah blah blah...... But, my case never worked. The key reset thingy never did squat.

HERE IS MY FIX:
1. I broke my key open by sticking a thin screwdriver (firstly) into the back end of key and twist all the way around. I figured "what the heck".... can't do anything worse than what I already got......

2. Remove the green printed circuit board (PCB) from the fob and inspect battery (looks just like a round waffer watch battery) which is welded into a wire holder. (Battery is rechargeable and therefore not removable from the wire holder without breaking it)

3. Upon inspection, you will find TWO areas where the battery wire holder attach to the PCB. Flip the PCB over and you can see (2) big blob of solder holding the wire ribbon on the other side.

4. While holding the PCB so the battery is facing you and ***key side pointing up***......... The failure mode is the left side. Pry the (left side) wire ribbon up and you will see it pops out very easily and is corroded or the connection is very poor with the solder.

5. You need to re-establish the connection. Personally, I bot a solder kit and poked the wire ribbon back into the hole. Then, I melted the solder on the other side of the PCB and made sure the ribbon was formed into the solder.

6. I used Gorrila glue to glue my key back together....but, you can use anything.


Wallah!!! It saved me $138 per key (Dealer quote)..... Both of mine were NFG. Same issue. AND I COULDN'T BELIEVE THAT NOBODY HAD POSTED ANYTHING LIKE THIS...... MAYBE I'M THE FIRST TO FIND THIS FLAW OUT???

 

There have been some cases in this forum where non-working remotes were fixed by replacing the rechargeable battery. Rechargeable batteries do wear out over time, but it's possible that in some of those cases the actual problem was a bad connection, not the battery. Replacement batteries cost only a few dollars each, and it would be a good opportunity to go ahead and replace it anyway while the fob is cut open.

 

Bad solder joints unfortunately are almost expected in electronics of this era....
In European/euro compliant electronics, some items, like lead and other less well known metals), etc were eliminated, most all solders had to be reformulated....usually with larger amounts of TIN (cheaper than silver).....net result was early failures that still plague MANY industries....it is especially acute in Aviation.....with documented studies of tin crystals growing from joints and frying entire circuits.....
after a couple years, of fighting with the newer, harder to work with solder formulas, and some early failures, most manufactures switched to surface mount technologies, like conductive glues.....
Glad you found the issue!!

 

That always made me curious about the engineering decision to use rechargeables. So the OEM fix is to get a new key when it inevitably dies, or they just assume people don't keep cars long enough for it to be an issue?

 

Planned obsolescence..... And a future revenue stream...
Since few original owners will own a car beyond the first 4 years, OEMS tend to forget about longterm costs...working to reduce costs for the first couple years....all the "lifetime" fluids used in cars kinda prove this.....

 

"Planned obsolescence"
We see this in other Mini applications like the "Lifetime" SuperCharger oil.

"Lifetime" is defined as the length of the OEM warranty. Past that, manufactures don't give a damn.

Good job on your fix. I don't know if I'd have used Gorilla Glue, I'd probably have used a Silicone or something less permanent.

 

My band, Tin Whiskers, is named after this phenomenon, since we're all over 50 and have, well, tin-colored whiskers!

 

This guy can do repairs to the '05- '06 keys:

http://bmwgm5.com/

The '05- '06 MINI keys are essentially the same thing as the BMW diamond shaped keys, just in a different case.

They differ from the earlier clamshell keys in that the key is sonically welded together and the rechargeable battery is soldered or welded in place and therefore not user-replaceable, in addition to having a circuit board, etc, from the BMW side of things instead of the Rover side.

Bruce