Smart Key Has Decoded - How to Fix?

[Keep it stiff]

The Smart was parked in my driveway last night with the key left in the ignition by mistake. It won’t start this morning, the key seems to have de-coded itself, you get the odd bleep but mostly just the key sign flashing on the dashboard. The car locks/unlocks fine, I took the key away from the car and tried again an hour or so later but still nothing.

Are there any steps I can take to get the key and car to start relating to each other again or does this mean an expensive trip to a dealership to get the key re-programmed?

I have just the one key for the car.

[mbtech01]

unfortunately the car will have to be taken to your dealer or nearest specialist where it will have to be put on the Mercedes Star diagnosis computer & then a code neads to be obtained which is then input into a key generator code program & this in turn will give an authorisation code which is input into the ecu & then the key can be programmed to the vehicle & hopefully allow the vehicle to start.
One point that maybe worth trying before you get the car to the dealer or specialist is to replace the keys battery & check the battery terminals have not broken. A new battery sometimes kicks the key back into action & i have seen the terminals holding the battery break off before not allowing the battery to work.