Key Fob/Remote Confusion!

[robs-mbz]

I've discovered today that the key fob for my W210 starts the car with no batteries in it! Is this normal? If so then how the hell does it work!

 

[television]

I've discovered today that the key fob for my W210 starts the car with no batteries in it! Is this normal? If so then how the hell does it work!

the battery is only for the remote, the IES lock(transponder) sends out a signal to the key, that resonates at the correct frequency or that,that the key is programed for.

Malcolm

 

[robs-mbz]

Ok, so is the signal that the lock sends to the key an RF signal? How does the key respond back to the lock?

 

[television]

Ok, so is the signal that the lock sends to the key an RF signal? How does the key respond back to the lock?

All of our car are dual RF and IR with the exception of the 203 on that there is no RF just the IR.

with the ignition it is a DAS(drive authorise system) it is that that has the transponder, the door lock are just cut keys.

Malcolm

 

[alec2]

Ithink you will find that the 203(C Class) has 3 systema on the key fob.

1 The RF for normal door unlocking and alarms.

2. The IR for the drivers window trick.

3. And the immobiliser fitted in the ignition switch and activated when you insert the key.

1 & 2 are powered by the batteries and can be resynced if the batteries fail.

3 recieves it's power from the ignition switch by induction and and cannot be resynced if it fails for any reason. New key from merc is needed at about £120.

I suspect that the current E Class and others use this system also.

Alec

 

[Big Gav]

AH? SHOOT!!

My keys not working and by the looks of things on here im up the kyber!!

ive got a spare key but it's a lot thiner than the normal key and does not have the buttons on it.

I read on previous threads that if you had a second key you could re-programe the original key? i take it from this responce thats not true?

i now have to have 2 keys on me, one to open and lock the car and the thin spare key to drive the car.

I think it's gonna be a trip to my local MB dealer to price up a new key. (great! and just after a service!)