Modern Vespa

Hi,
I recently posted here about issues I'd had with my 2021 Vespa Primavera and am looking for some further advice about the issue. First time it happened, it cut out up a small hill but I had been riding it a fair few hours and it didn't start up again until next day.
Second time, I was riding along, and going down hill to decease my speed into a 20mph zone from a 30 and my Vespa just cuts out and totally shuts down. Thankfully I had enough momentum from the hill to pull into a lay layby where I fired up and she restarted again shortly after.
I've been told by a reputable, popular Vespa/Scooter mechanic in the area that it's possibly an ABS sensor fault or an ECU fault which would mean having to change it.
Others have said it could be kill switch.
It cut out. All dashboard lights momentarily lit up and then there was absolutely no life in her at all. The ABS light does and always had stayed on when I stop at traffic lights etc which I'm also told is an issue (which I was never aware of as I'd never had a scooter before).
Looking for any advice possible please as I'm on verge of cutting losses on something I love very much.

Sounding like a fuel pump.

You mean all the lights went out? If so check battery terminals and fuses.

That's normal behavior. Nothing to worry about.

The ABS will not cause the engine to cut out

No issues with them, faultless apparently.

What do you think it could be? Poor connections somewhere?

Is it really? Everyone that I've spoken to says it shouldn't be on constantly like that and that it should have gone back to manufacturer under warranty

That was serviced, and it still happened

Oh, on constantly? Blinking at a stop is normal. If it's on steady there could be an issue there.

It isn't on constantly no sorry. Just when at traffic lights and coming to a halt. Apparently it shouldn't do that?

ABS is active at around 10 mph so light on less than that off greater than that. Probably says that in the manual

Suddenly totally cutting out (as opposed to just the engine dying) is 100% certainly an electrical connection problem, not a fuel problem. Assuming you've already checked the battery and fuse connections I'd start by swapping out the ignition switch - cheap and easy to do. They are a known common failure point, and it'd be worth having a spare anyway if it proves not to be the culprit.

Thank you. Just taken a look and again, bloody panelling needs to come off to get to it

But were any of those you spoke to aware that is a quirk with Vespa? As stated above, that is normal. It is stated in the owners manual as well.

99% chance is you have a loose connection or broken wire as also previously stated. I had a broken wire going to the throttle body and the diagnostic tool said it was the throttle body. I have a great mechanic and he lets me watch without charging me double

Thank you. It's checking the wiring by removing panelling then yeah?
Try and find a mechanic in Wales but happy to be given suggestions 🤣

Check the battery connections.

You should be able to get to it without removing any more panels - but it'd probably be easier and certainly less blood-pressure inducing to start by removing the glovebox bit. It's what I'd do. Don't forget a rubber band to help keep the glovebox latch in place when you replace it - otherwise you won't get into the glovebox again without much, much more aggro.

Yes we made that mistake before lol. Now I can't close fully the glovebox do it'll have to come out anyways I reckon 😄

the tendency for somebody who doesn't understand electronic things to blame them is way too common. reputable?

Quite. If all lights etc go off it can't possibly be an ABS fault.

Look for the very few things that can cause this...

And if it's happening when you go up or down a hill then something isn't tight enough somewhere.

Which are? Sorry to ask such a basic question but I know next to nothing sorry

Yep. Every scooterist and biker I asked all said there's only one man to go to. And he said the above

This started happening after a service with the aforementioned guru?

Vespa cutting out, even after a service (Post 2684695)

It's probably a loose spark plug lead (he changed the plug). Assuming that it's not that battery connections that people keep telling you to check.

No it happened before, that's why I went to him.
Then it still happened after I picked it up on my way home

A thing to note, the behaviour of the ABS light on a Primavera is different to on a GTS. ie what might be correct on a friend's different model doesn't mean correct for your model.

The savage amount of rust in your earlier post about breaking the brakes could be a hint.

Certainly supports the hypothesis that the battery terminals are significantly corroded and/or loose.

Also how did you check the fuses? With your eyes or a multimeter?

On the GTS, there's ABS front and rear. The ABS light should be off at all times while riding.

On your Vespa Primavera / Sprint, there is only ABS on the front. The ABS light should flash on at all times when the Vespa is stationary and turn off at all times when the Vespa is moving. This is completely normal behaviour.

Also, I've not really seen ABS issues come up on this forum.

Can you undo the section in the floor to reveal the battery, and take a pic for us? If the battery isn't secure and can move a bit - this could cause the Vespa to cut out when there's more movement forces - heavy braking or on a hill. I'm wondering if any of the battery leads have worked loose and need tightening.

Where's your nearest main dealer?

There's M&P in Swansea but I got mine from north Wales. No idea in terms of Piaggio dealers, none local that I know of. What were you thinking?