Ouch! I don't envy you.
I too have an intermittent key, but mine is the remote lock/unlock function which stopped working for a while only to once again work. Both would start the car.When I bought the car, only one key fob would start the car, but both would unlock/lock. New battery in both fobs, no change.
For no reason, the fob in question started working, I was trying it out before shipping it to SOS diagnostics. I thought I was
back in business with two keys that worked!!! Well, this little gremlin likes to play, and I am his unwilling partner so to speak.
After a month or two, using the problematic fob, it failed again... and yes... I was away from home with out the backup fob.
Took it to the MB dealer, they reprogramed it, it worked great... for 24 hours, then back to its unreliable self again.
So, after another couple of months, with the bad fob left in the car so I could randomly try it... it worked!!! I am using it again
but this time with the second fob always available.
I have removed the fob guts, looked for dirt, junk etc... blown it out and cleaned the all the rubber contacts... but still find
it strange this gremlin likes to keep messing with me.
Sending both fobs, the Sam, and ECU to SOS seems like the next step, when it fails again...!
Does anyone have any idea what could be the problem with this key fob? I am fortunate my backup works fine, and hope to
keep it that way.
The smart key fob uses mechanical switches. The rubber buttons just press on these switches. I understand you may be trying to prevent their slight protrusion from activating the switch.T Sounds like we have the same/opposite problems. If I do send this to SOS in the future, I hope that is the end of the gremlin!
I did have problems with lock/unlock activating with the key in my pocked. I tried to sand down the rubber thingies (technical term) with a
nail file, and it worked... although I had to do this a couple of times. So no more unwanted locking/unlocking for me!
Is that cheaper than getting a new key through the dealer? When my mother was robbed with her Mercedes key in her purse I went and got replacement everything and they reprogrammed the remaining key, erased the missing one, and programmed the new one...JZ Yeah, that will probably be the next step, when it fails again. Its just having to plan parking the car for a week or so
to allow for mailing the components to SOS for the repair/replace, and then reinstalling such when it comes back.
When the battery gets low, the car will flash its lights nine times (yes, its true!) - letting you know the battery needs to be replaced. Covered in the owners manual.How often should the keyfob battery be replaced?
Nope, just plug and play.CR2016? Got it!
After you change them: do you have to preform any reprogramming tasks?
(I don't have a manual...)
FYI, I have a 2016 Fortwo and my key fob takes one CR2032 batteryTakes CR2016. I've got them on hand. Guess maybe it's time to think about using them.