Key No Longer Works - Any Ideas

[Smurf]

Hi guys and gals,

 

Last week my remote key fob thing suddenly stopped working. I've had my C4 VTR+ Coupe since April 2005 so guessing it could just be a dead battery.

 

What's strange though, is up until it stopped, the key was triggering the locks from a good 20-30m away and there was no sign that the battery was failing. Also, the key works in the ignition so I'm guessing there is some power left?

 

Before I order a new battery or call the dealer, I was just wondering if anyone else has had a similar problem with their key?

 

Thanks!

[Welshguy]

Hi guys and gals,

 

Last week my remote key fob thing suddenly stopped working. I've had my C4 VTR+ Coupe since April 2005 so guessing it could just be a dead battery.

 

What's strange though, is up until it stopped, the key was triggering the locks from a good 20-30m away and there was no sign that the battery was failing. Also, the key works in the ignition so I'm guessing there is some power left?

 

Before I order a new battery or call the dealer, I was just wondering if anyone else has had a similar problem with their key?

 

Thanks!

 

I dont remember anything being mentioned other than the build quality of the fob. You may want to contact kfk on these forums - he'd probably be the best man to ask.

[Smurf]

I dont remember anything being mentioned other than the build quality of the fob. You may want to contact kfk on these forums - he'd probably be the best man to ask.

 

I'll give the dealer a call and see what they say.

[Guest CE05LDB]

Ive had my C3 Exclusive since April 2005 and my remote key is still working fine.

[Z3M Roadster]

I've had my C4 since Feb 05 and the battery is still fine. Does the battery re-charge inductively through the steering column when the key is in the ignition?

[billynibbles]

Aren't we getting our systems mixed up?

 

Doesn't the fob's battery only power the remote central locking (and headlights on/off function if you've got it).?

 

On all the cars I've had lately, the encoded immobiliser chip inside the key works by induction from being near or in the steering lock barrel, so it's not battery-dependent.

 

This would explain why, with a flat fob battery, the car will start once it's opened with the key manually, but refuses to be opened remotely from the key fob.

 

Of course, once they start completely removing ordinary door locks, we'll be well and truly up that well-known creek without a rowing implement. My wife's Smart's like that already leaving us to climb in through the tailgate if the battery in the fob dies on us. Not a pretty sight.

[Smurf]

Aren't we getting our systems mixed up?

 

Doesn't the fob's battery only power the remote central locking (and headlights on/off function if you've got it).?

 

On all the cars I've had lately, the encoded immobiliser chip inside the key works by induction from being near or in the steering lock barrel, so it's not battery-dependent.

 

This would explain why, with a flat fob battery, the car will start once it's opened with the key manually, but refuses to be opened remotely from the key fob.

 

Of course, once they start completely removing ordinary door locks, we'll be well and truly up that well-known creek without a rowing implement. My wife's Smart's like that already leaving us to climb in through the tailgate if the battery in the fob dies on us. Not a pretty sight.

 

Good point. I'm surprised Smart do not supply two remote keys?

 

Spoke to my dealer regarding faulty key and they're none the wiser. Ordering a new battery now to see whether it helps.

[Smurf]

After trying a new battery and the key still not working, I gave the dealer a quick call and asked if they had any further ideas. They didn't.

 

Never being one to give up, I finally resorted to doing something I never do and turned to the manual for help....

 

First thing I read is that the C4 has a built in warning if it detects a low battery in the key! It'll make a noise, display an error message and light the 'Service' sign.

 

The crucial bit is that after removing/changing the battery, you need to reinitiate the key by putting the key in the ignition and pressing the 'lock' button on the fob. After doing this the key works again! Somehow my key must have lost its 'link' to my car.

 

Moral of story. Read the manual before calling dealer and ordering batteries of ebay! :blink: