TheUnscented

On my 2012 CTT (958) I often get an error "Key not recognized" in vehicle. It's happened maybe 8% of the time when I go to start the vehicle. Occasionally it will advise me to change the key battery, which I've done....several times. It's happened with both keys with new batteries from multiple sources. Using the correct CR2032 3 volt battery.

It's been annoying but when it error popped up "Key Not Recognized" while I was driving, I'm afraid I'm going to get stranded. Have appointment with dealer on Monday. It's got to be the key sensor on board the vehicle. Is this an uncommon problem?

booch

I see that every now and again in my GTS; usually when the key has been in the car and it's in the door pocket. If I move it closer and re-attempt the start, it always fires up. I'm not concerned by it but next service I will mention it and see if they have any history with the problem.

deilenberger

I think we've all seen this on the KESSY equipped cars. If my key is in my pocket, behind my cell phone that's in the same pocket I'll see it - easily cured by moving the cell phone or key so the key is closest to the dash. There are multiple key sensors in the car (and outside it) - but if none of them get a good signal from the key, you're going to see that message.

r553

Does the freshness of the fob battery make any difference? In my Mazda I thoughtfully get a no start when the fob battery is low.

deilenberger

The Cayenne will warn you when the battery is getting weak.. and I've never noticed any difference between a "fresh" battery and one that's been used a bit. Both can give the "Key Not Recognized" message - which seems to be a radio-wave transmission problem rather then a battery problem.

thescratt

I've seen this around construction sites sometimes. I put it down to radio interference of some kind.
Recently our neighbour started building and they have a crane setup with some kind of remote as well as a generator, and I've seen it a couple of times when they've been doing things and I've gone to open / start the car.

gadgetrex

My experience is that the error (key not recognized) occurs whenever my key has been in close contact with another Bluetooth emitting device; e.g., my phone. The worst is when I was using a Tile device (both the original and the newer, smaller Tile Mate). I had to give up using the devices.

User 52121

I started getting this recently - and it was *right after* I swapped out the key case/cover for a cool aluminum-look one (so it makes the key look aluminum vs. black plastic w/chrome). I wanted to be able to easily tell/feel the difference between the key for my Cayenne, and the one for my wife's Boxster... as on more than one occasion I've hopped in her Boxster, used the wrong key, and had a minor heart attack when the car wouldn't start... only to later realize, "Oh, that's the Cayenne key."

Well whatever this case is made of (it's plastic...) it seemed to cause interference because I was seeing the "KEY NOT RECOGNIZED" a lot. I swapped the case back out for the stock one and it's been good since.

That probably doesn't help you... but this will: If you cycle the dummy key twice (in an attempt to start it), and you still get the "KEY NOT RECOGNIZED" error, you should hear a click (along with an alert on the screen) and you should be able to easily REMOVE the dummy key.

Then just stick your regular key (the one that's usually in your pocket or whatever) and start the car. That will always work. That way you're not stranded.

TheUnscented

OmniGLH,
Thanks for the reply. 24hrs at dealership they say they cannot replicate the fault with either key and no codes thrown. I suppose I'll just go get it tomorrow. I didn't know the dummy key could come out, that really puts my mind at ease.

AGARubberDuck

Mine did this to me this morning. Key was in my right pocket as usual, but I tried to start 5-6 times. Took the key out and laid it in the cup holder and tried 3 more times before it finally decided to recognize the key. Not a cool experience to be sure.

Side note, previous owner apparently hulked the dummy key out at some point because when I tried to press the small button and remove the dummy, it slid apart into two pieces quite easily. Normally I wouldn't care, but if I need to use the key in the ignition I'd struggle at this point since the dummy key is effectively stuck.

bweSteve

happens to me every so often. doesn't usually bother me, and similar to gadgetrex, I usually attribute to being close to my phone when Bluetooth has been left on (or maybe it's something else).
I've owned the vehicle for 3 yrs now, and experienced this maybe 3-4 times a year.

not a biggie for me. I'm not worried, nor will I do anything about it. Happens so seldom.
=Steve

Dalema

I recently had a similar experience (changing the battery didn't help). Warning kept popping up while driving. Anyway, dealer found the back passenger door handle for easy entry wasn't working and has replaced it - believes that was the issue. Will see if it fixes it.

wkearney99

Are you sure the batteries are good? I've got a tester that measures batteries based on a load, not just on voltage. This after a spate of bad batteries in some wireless shades. They take 10 batteries each, and one or two bad ones will lead to intermittent problems. Which has nothing to do directly with your key problem, other than to say make sure the batteries are actually good. I've had batches of the coin cells that seemed ok until they'd been in a gizmo and used for a few times. Turned out the whole card of them was bad. Not quite the bargain I'd hoped...

This is the one I use:
Not cheap, but it'll check darned near every kind of battery.

As for your key problems, I've found the keyless entry system requires the key be within 2m of the B pillars on the side or the rear liftgate. Never checked it from the front. I tested by moving the key closer and closer until the door would unlock based on putting your hand through the handle. Any farther away and the antenna wouldn't pick it up. I'd wonder if a test of yours would confirm that?

It also checks 'something' to determine if the key is inside the vehicle. I don't recall how. I don't know if it coordinates with the pillar sensors or something else inside (or both).

AGARubberDuck

Actually, I mentioned the problem to my dealer when it was in to get the rear diff looked at. They tossed in a new battery and I haven't seen the issue since.

Interesting though, my 955 would tell me when the battery is getting low. Does the 958 no longer do that?

TheUnscented

Yep. The batteries are new and correct. The dealer even replaced them again. Four more episodes since leaving dealer. Something I'm going to have to live with....