Modern Vespa

I am having some starter problems today.
This morning, I turned on the ignition and hit the starter button and nothing happened. Everything was running fine yesterday.
So I started troubleshooting.
This is on a 2019 GTS300
Battery is at 13.3 v Lithium battery
All the fuses in the glove box are good. 10 Amp checked twice
The brake switch works
The side stand switch is good
Starter relay works when jumped. (turns over fast)
> White and Black wire has power with brake on
>Orange/blue wire 0 voltage with or without starter switch on ???
Starter switch is good.


I am not really sure what the Orange/blue wire on the relay does. The wiring diagram says it goes to #10 on ECU. I would think it would be some sort of ground for the starter relay?


What am I missing? That starter motor should be spinning when I press the button.

TIA

If you check all the previous things maybe is the immobilizer that is avoiding the engine starts? Do you see if the red light in the dashboard is going off and remain off? Not sure but maybe the Orange/Blue wire form the ECU is exactly a signal from the immobilizer?

I have a similar symptoms with my MP3 250 and it was the immobilizer antenna that was not working and therefore did not read the key. Change the antenna and all return to normality.

toggle the kill switch a couple of dozen times (yes, seriously).

as dariusz asked, what's the immo light doing?

you checked the brake light, but did you test *both* levers or only with one? it's easy to vague out and test one but use the other when actually pressing the starter.

how did you check those fuses? eyeballs dont' always show bad ones

what lights on the dashboard are lit / unlit?

Yes, I toggled the kill switch to no avail.
I pulled the wires off the brake lever switches, and checked for continuity with a VOM. Same for Side stand. Checked all fuses with VOM.

I will check the immobilizer and lights in the morning.


Thanks for the quick responses

The immobilizer is not coming on.
The only lights I am getting are the ABS, engine and oil pressure

Just for grins today, I removed the orange/blue wire from the starter relay and replaced it with a ground wire. I turned on the key and just grabbed the front brake lever. The starter spun, and the engine started before I could let loose of the brake lever. I never touched the starter button

Now I am really puzzled ???

It appears that I have something going on in the ECU.
My problem must be some sensor somewhere???

Any suggestions?

Well, I ordered the immobilizer antenna from ScooterWest. At $180, I sure hope that that works. Without the ability to pull codes, I am just shooting in the dark.



Since I got the bike, my engine light has been coming on and later stopping on its own. It will be interesting to see if the antenna has any effect on that.

that's good, it means it's working. too late to cancel the order? DIY Diagnostic tool for injection Vespa's with MIU ECU
or
https://www.scooterwest.com/diagnostics-tool-cable-for-2020-gts-hpe-2020-mp3-500-bv400-2.html (same model can probably be purchased cheaper from amazon etc)

I sent a request to cancel. I may be stuck.
I will order that scanner today. All the rest of the scanners I have inquired about told me that they didn't cover my bike. It would be great to actually have a scanner.

I just ordered the scanner from Scooter West.

I am at a standstill until the code reader arrives. I sure hope it provides some information. I sure would like to get my scooter back on the road

other things to check while you wait:

the connection to the temp sensor. think the ecu will refuse to start if this is not connected.

throttle fully closed. check the black thing on the throttle body is resting against the screw (don't adjust the screw ever).

maybe the starter button is f'd. disconnect it and bridge the connections to simulate pressing the switch.

while you have the handlebar covers off you can bridge the kill switch connector in cause that's f'd.

and jsut generally wiggle wires and connectors in the engine bay.

Problem Solved
I was the cause of my dilemma
Lesson learned

I was following up on SB suggestions and immediately saw the potential problem. It seems that I never got the memo on the throttle body screw. I have been adjusting that screw since day one. I also remember one of the last things that I did to the bike was speed up the idle. So, I backed off the screw a bit. The scooter cranked up, just like it is supposed to. The scooter runs great, no warning lights. All is good

Many thanks to SteelBytes and all that contributed.

Happy you're running again

It's not an idle adjustment screw.

So I have learned