Spare Key Remote Trouble

[800]

The questions start already.......

So, have my nice old C280, going like a dream.

Have the two infra-red key fobs, one works fine, but not the other one.

Have read the manual (unusual for me) have pressed the fob at the receiver (rear view mirror) have turned key in ignition for 30 seconds to re-initialize, as instructded.............................nothing!

Any ideas before a make a Muppet of my self at the local dealer?

[GregE240]

Tried replacing the batteries, or at least swapping the ones out of the working key into the non-working one?

[sneijder]

See if the end of the key where the beam comes out is badly scratched or even chipped, as this 'scatters' the beam. If the red light comes on, the batteries are fine.

[800]

Thanks for the help.

Batteries are fine, red light comes on. Only a slight scratch on the IR cover.

[mercedes tech]

hold the key at the mirror press the unlock button and keep pressed, whilst keeping unlock button pressed insert key in ignition and turn ignition on, then proceed to press button 5-10 times. this should make it sync in