key code lost

After having problems with the flick out key on my 2006 Ducato I changed the battery and the remote works fine now
However it now will NOT start the van so I must have lost the code or whatever allows the engine to start so any body had this problem and know a way I can fix this without having to have the key recoded
David

I had a similar problem last year , my key wasn't working either,you can do an emergency start if you have the key card code which it imputed through the accelerator pedal. I removed the signal box under the steering wheel column to have it recoded but after a bit of advice i refitted it and recharged the vehicle battery and hey presto the van started. I was informed that if the vehicle battery falls in voltage the key signal box wont work properly.So my advice to you is have the battery charged check the voltage while cranking the engine. Is your immobiliser light staying on whilst trying to start the van ?