Modern Vespa

So the roll lock isn't locking on my MP3 and I don't get an error light nor alarm. I found the fluid reservoir empty so I filled it with DOT 4. My next step (I assume) would be to bleed the lock mechanisms on both wheels. Is this correct or is there something else that needs to be done?

Edit: OK, I just read the post by Alex87 and got some useful info. I guess I should track down the leak before refilling.

Still, it's strange that the scoot isn't complaining about problem.

Probably because the sensor isn't dry (yet)

I'm almost certain the sensor senses pressure, not moisture. Anyway, I'm going to locate it and see if it's leaking. Hope not, because they're pretty expensive.

I attached a picture to show what lights are lit on my dash. Other than the wrench symbol (which I think is an oil change warning), nothing else seems out of the ordinary.

The tilt-lock is notorious on the MP3 for leaking. You'd think a main feature like that would be better engineered or at least access to the reservior would be easier. All three of mine suffer from this. I find if at the first sign of honking I fill it it is good for awhile.

Odd that yours is not honking but also not working. If it were a faulty pressure sensor it would most likely honk. This makes think it is electrical or mechanical.

I have repaired this on one of my MP3's before (as well as others that came into my shop).

A 2009 MP3 400ie.

Usually, a failing sensor causes the horn to honk a multi-beep warning when you turn the ignition on.

What year and model are we talking about here please?

In the case of the 400, (and others I suspect) there is a pressure sensor which is a hybrid metal/plastic component. Mine was under the nose cone, attached in the back to the brake line assembly.

Eventually, the heat and vibration cause the fluid to leak from the point where the metal and plastic come together.

Thanks guys. Mine is a 2009 MP3 500. I located the sensor and there's no obvious sign of leakage, but since the system is empty anyway, I'm going to remove it to have a closer look. The price for a new sensor sure is eye watering.

They sure are expensive!

But as brake fluid does not evaporate, it's very important that you locate the source of the leak.

Even mine really didn't have a wet area around the sensor. It was kind of strange and caused me to think that it had leaked very slowly over a long time.

Good Luck!

I was at Cadre Cycle in Cincinnati, Ohio yesterday.

Enzo, the owner, showed me a beautiful black 2009 MP3 500 that he took on trade for a new GTS Vespa.

Enzo knew that the MP3 had some issue but he had never encountered this before as he is a new PIaggio dealer. He asked me and I was delighted to be of assistance.

As is common of the MP3's I saw and worked on in my professional shop, the reservoir for the tilt lock setup (it is in the nose cone under the fairing) was bone dry. (Out of sight and out of mind for almost all owners.)

Because there was no pressure in the system, the alarm sounded the horn 4 times every time you turned the ignition on, which is the alarm to notify you that there is an issue with the system.

Again, these hybrid pressure sensors are all leaking at some rate by now simply due to age.

Most that I worked with, had leaked so slowly and for so long, that you literally could not find any liquid fluid anywhere.

In fact, the first time I did one of these repairs, I nearly tore my hair out trying to find where all the hydraulic brake fluid had gone to!

Those pressure switches are expensive at about $160 but they are a critical component.

The strange thing on my scoot is that there are no lights on the dash indicating a problem with the roll lock nor is there any beeping from the horn.

I found a place online called scooterpartsco.com that sells the sensor for $94. Supposedly the part does not come from Piaggio, but directly from the manufacturer that makes them for Piaggio. Does anyone have experience with this website, good or bad?

Yes, I purchase things with them, maybe a little slow to shipping, but all goes well. The owner (Motovista) is active on the forum too.

The part number is: 640295

But I doubt that a $93.27 price can be beaten. I purchase in 2022 two of them in $152.46 each (the best price I can find in that date) and now in the same place cost $186.99 each.

Here a reference to the original post as motovista find the part: Tilt Lock Pressure Sensor 640295

Great, thank you dariusz.

A good way to tell if a sensor is going to be insanely expensive is to look at the application chart. If every model listed is a Piaggio, it usually is. Many of the sensors used by Piaggio are common parts that are made around the world by companies like MTE-Thomson, for example, and used by Honda, Yamaha, companies that make cars, etc. These can be had for a reasonable sum. The Tilt Lock Pressure Sensor isn't one of them. AFAIK, there is one company in Italy that makes them.

Thanks Motovista. I ordered one of the sensors from your website.

Replaced the roll lock pressure sensor today. The old one was definitely leaking because there was brake fluid inside the housing where the electrical connector plugs in.

Tried bleeding the system using a Mityvac vacuum pump, but while I got some old fluid out and the reservoir level did drop (very slowly), I got mostly air coming out. I pumped for at least half an hour and got the same result.
I must be doing something wrong or there is an air leak somewhere. And yes, the new sensor is tight. The body of the sensor is aluminum so I don't really want to crank on it elsewise I break it off and ruin my day.

I have another brake bleeder that uses compressed air to create a vacuum to suck the fluid out in a steady stream. Maybe I'll try using that.

Anyone have any other suggestions?

Using a syringe at each front wheel, I pressure bled the roll lock mechanism today. Interestingly, no air came out of the reservoir, just old fluid. I basically just flushed the old fluid out and replaced it with new.

The amber roll lock indicator (E = Front suspension locking system warning light) on the dash now flashes a few times when I activate the roll lock switch, then goes out. I heard a single beep once, then never again.
There are no other sounds. When activating the roll lock, should there be any sounds or movements of the roll lock motor? Mine does nothing. Does the engine have to be running for the roll lock to function? Do I have to be sitting on the seat? (tried it, nothing different happens).

I checked the fuse (n.3) for the Parking Control Unit and it's good.

Sorry for all the newby questions. This is all new to me.

sounds like a good flushing was needed and you might have gotten that 1 or 2 pesky air bubble trapped to wiggle out.

it should do a beep when turning on or off with the switch , no sitting on the seat is necessary nor do you need the engine running.

while on the center stand, key on, double click the tilt lock switch to unlock. wait a few seconds and click to lock. Then try it again off the center stand with your feet firmly planted on the ground because when it unlocks it can fall over if you're not supporting it. then relock and put back on the center stand.

Thanks, I'll try that. I assume when the locking mechanism is working, there should be some kind of movement going on with the locking motor? Mine does nothing. Also, like I mentioned, I only heard it beep once and never again when activating the roll lock switch.

Try checking continuity from the ECU for the roll lock to the wheel sensors some times they go O/C and cause a fault like you have.

Thanks for the tip. I'll check that out for sure.