Changing Fob Key Battery

[VeeCee]

Hi,

I am new to the forum and having searched on this topic I could not find an answer. I have a C200 2002 yr model and a few days ago, I could not lock or unlock the doors. The AA man told me that my fob batteries are down. I managed to get a lift home, get my spare keys and use the car.

I replaced the fob batteries with identical ones. The red light on the fob comes on but the locks do not work. I tried with another brand and still the same. One of my friends told me that the batteries need to be replaced within 30 seconds, otherwise the memory is erased. I do not want to try the new battries on my spare key fearing I might not have a usable key.

In the forum, i found " In general, there is a procedure for changing batteries in the key fob and also one for locking and unlocking and changing or reinitialising codes (which you now need to do having disconnected the battery. )

I would be grateful if someone can tell me what this procedure is.


VeeCee

 

[panason1c]

This 'synch' procedure is for a 2002 ML but worth trying on your vehicle......


Turn the key to position 2 in the ignition lock. Then turn the key to position 0 in the ignition lock and remove.. Within 60 seconds press and hold the (picture of CLOSED padlock shown) button on the keyfob...Then, press the (picture of a OPEN padlock shown) on the keyfob button 5 times

Check all functions....repeat all above if still not functioning correctly

Hope this helps

 

[VeeCee]

Thank you.

Unfortunately I am unable to turn the key wit the dud key fob.
Any other methods?

VeeCee

 

[panason1c]

As far as i am aware the key should still be able to turn and start the engine regardless of whether the fob batteries are ok or not, the above procedure is only to 'sync' the lock/unlock facility and the fob batteries only power the radio signal so dont know why the key won't turn....is the gearlever in 'park'?.

 

[joe bloggs]

Can you hear the steering lock release motor when you insert the key, often the cure is to leave the key unit in the lock for a bit while it tries to establish a valid code. (1 hour or so, if not then looks like the unit is junk) Batteries not required for ignition part of fob.

 

[VeeCee]

Hi

Thank you all for your advice.
The steering lock release motor does not come on with the dud key.
I think I have to order a new key.

Thanks again

VeeCee