Modern Vespa

Has anyone ever opened a throttle body (the side with the electronics)? And did you happen to take a picture of it? I have starting problems and I am very sure these problems are caused inside that ECU. Pin 5 receives 12Volt from the start button, as it should do (2014 type with ABS). And sometimes it starts, but more often it doesn't. And if it doesn't start, I hear a small click inside the ECU, like a tiny relay. But on pin 10 I do not get ground/earth as neccesary to trigger the starter relay. The problem originally occurred when the engine was hot, cooling down was enough to get it starting again. But now I have discovered that a light tap on the side of the ECU solves the problem for a while. So I strongly suspect bad soldering on the ECU print, in the direction of pin 10.

That's why I wanted to see the inside without having to open the thing right away, just to make sure re-soldering is an option.

Did you ever resolve this issue? I have a very similar problem

I did opened up the throttle body, but there where no visible bad solderings. I installed a second switch, which triggers the starting relay directly, but I think in the end I will have to install a new throttle body (€600), with no guaranty the problem will be solved, and no money-back-option.
The only problem with the second switch is the risk of engaging the starter while the engine is running, so I installed an additionnel switch to prevent that from happening 🥴

You didn't say what model.

Anyway here's the insides of the MIUG3 from a MotoGuzzi. It's the same ecu as in the GTS 300 2015-2019 except some of the harness connector pins may be swapped around.

Source: https://wildguzzi.com/forum/index.php?topic=120775.0

As I mentionned in my initial question, it is a 2104 GTS300 ABS. And you are right, it is a Moto Guzzi écu, I use the Guzzi software to read/reset the GTS écu🙂
And I already had a look inside my throttle body, nothing strange in there...

Looks ok, but we all know Italian electrices/electronics😉

Sorry, must've been drunk.

So yes, your GTS is a MiUG3. pre-ABS was a MIU1 and the HPE is MIUG4.