First post after several visits...you all have helped me with other little annoyances about my baby. (2009 Cooper S hatchback, manual trans, 75K miles.)

Anyway, my key fobs work when they want to. Fully charged, switched back and forth between the 2 fobs I have...no difference. My car has the keyless entry/start option. Sometimes I'll be standing next to the car and the keyless entry button on the door handle won't work, and neither will the unlock button on the fob. (Ditto when trying to open the hatchback while the car is locked.) Then after a few seconds, I'll try again and it works. Also when I get in and go to start it, it won't recognize that the key is in the car (when it's not in the ignition, tho).

I'm gathering that the sensor is in the rearview mirror, is that true? Anyone else heard of this problem? I saw some older threads about resetting the computer by disconnecting the battery, but it didn't seem to solve the problem.

Thanks!
V.

 

You have comfort access with the non-rechargeable batteries. You say they are fully charged, do you mean they have new batteries or that you have had the key in the slot recently?

 

I put them in the key slot. Hm, if they are non-rechargeable, why did the folks at the dealership tell me "to recharge them occasionally" by putting them in the ignition slot? I know they store operational data for the service department, but that seems a wee bit misleading. (Not the first time, tho!)

 

Yeah it's a common misconception by dealerships. Try replacing the battery and see if that helps. Should be CR2032.

 

The slot charges the batteries on a non CA car, but for every car it puts that data on there for your SA to grab off. If you go in for something make sure to drive it for a few minutes with the key in before you go so they have the most up to date info.

 

Well, looky there! Yep, that's the battery. Time for a trip to good old Radio Shack!

I wish I had asked the question sooner, it would've saved me a lot of frustration.

Thanks all! I'm sure I'll be back with more silly questions. :-)

V.

 

If that doesn't fix it, check for any leaks along the top of the front windshield (or sunroof if applicable). When water leaks in, it can find its way into the rear view mirror and damage the sensor.

 

New '09 Cooper S owner. First fob stopped working 2 weeks ago, now second one won't work. Saw your thread about "slot vs batteries", and that you indeed found a battery in the fob. How in the world did you open it? It seems to be a single mold with no openings. Please let me know!!
Thanks,
David Dodd
New Orleans

 

non comfort access fobs are likely ultra sonically welded together. remove the chrome trim ring. i dont actually know how to do that. they broke off both my two keys years ago. Then slowly run a sharp knife along the seam between the two halfs. try not to cut yourself. once you cut enough you should be able to open it enough to pull the circuit board out. unsolder and solder in a new battery. I used plastic epoxy to glue the two halves back together. the battery is a VL2020 3v

 

I've actually had the problem for ages (I have comfort access and I also have new batteries). Its sometimes very difficult for me to lock/unlock the car from the rear but giving it a few tries will work after awhile. Its also difficult to use the unlock button on the doors and I've come to realize that it depends on where I'm standing relative to the door. If I'm closer to the front of the car or if I approached from the front, its usually fine. It must be some sensor near the rear of the car that is not working well. I remember looking up realoem and seeing that there are some sensors on each side of the car near the rear.