Modern Vespa

My LX 150 is new--only 480 miles on it. Yesterday I rode it to work and everything was fine but it wouldn't start after work. It turns but doesn't catch. I've had it towed back home and would like to fix it myself rather than paying for repairs. After looking at the boards, I'm thinking that the evaporator hose would be a good place to start. Any other suggestions?
Thanks...

Shouldn't this bike still be under warranty? I'd take it back to the dealer! if you do your own repairs, that might void the warranty.

When you turn the key to ON, exactly what sequence and duration of flashes do you get from the immobiliser LED, and does it stay ON or OFF?

LED flashes 4 times and then stays on. First flash comes on instantly, then a pause, next 2 are quick, slight pause and then the fourth light comes on and stays on.

Battery is very strong, engine turns over easily.

You have a programmed ECU, but the transponder or aerial is malfunctioning.

Have a read of the workshop manual, can be found at:
http://www.wotmeworry.org.uk/manuals/More%20Manuals/Vespa/

Try page 68.

Yesterday, I tried starting it with the Master key and had the same result with the 4 flashes and it wouldn't turn over. Today, I was going to take it back to the dealership when I decided to try starting it once more and upon turning it on, the LED did not flash and it started immediately. Is there any chance it re-set itself? Should I trust it or take it in for servicing?

Take it it and have the dealer check it out. You should not have had that error in the first place.

Agreed. Something doesn't add up.

Thanks everyone for your help. I finally got my Vespa back from the shop on August 12 (after 3 weeks). The ECU was malfunctioning and was replaced. It was under warranty or it would have been $2,000+. I didn't work on it myself and just took it in to be fixed which was a good thing seeing how it turned out.

Wow glad you didn't have to pay that Glad your back in the saddle and a belated aloha and welcome to the forum