2007 SportCity 250ie EFI error



I've searched the forums for this, and have learned some things but don't have an answer.

Started getting an EFI error on the dash during an easy ride on a moderate day. The light isn't on below 30mph and is on steady at 35 and up. No starting or driveability issues, although I didn't try to go over 60mph that day. The user's manual says "Don't ride it; See your dealer" and the service manual has lots of complicated steps involving an Axone tester which of course I don't have; I do have a multimeter. My nearest dealer is 90 miles away and I don't have a way to transport the scooter except by riding it there, so not a good solution.

I replaced the fuel pump myself in 2017, with the updated one, so it's not impossible that that's the problem, but it seems unlikely. Battery is four years old but still does its job. I did my usual oil/plug/air filter maintenance back in the spring, 1200 miles ago.

As I remember, in the last thread that addressed EFI, the culprit was the voltage regulator. Not that I want to throw parts at it, but that would be easier and maybe cheaper than dealing with transportation to a distant dealer.

I haven't done anything to it yet; looking for easy/cheap/likely causes before I start.