Modern Vespa

Can anyone help?

My 18 month old 300GTS is not starting. Battery seems fine and electrics are going through the motions but the bike's not starting. Fuel is OK...

Can anyone suggest what I should be checking please?

Many thanks in advance.

Toggle the kill switch a couple of times and then check to make sure the spark plug wire is on there nice and firm.

We need a little more information before we can help.

When you push the starter button is the engine cranking (turning over) briskly?

If the answer is 'yes' then we're looking in a different direction to if the answer is 'no'.

@simon64ds

Hi there, the engine isn't cranking.

OK, with the ignition turned on does the brake light come on when you squeeze the levers? If not, take a look at the rear light bulb.

If 'yes' take a look at the battery terminals and make sure both are clean and tight.

Do you have access to a multi meter?

I've fully charged the battery thoughout the day. I don't have a multi meter but electrics are generally responding and the brake light is coming on. The scooter is 3000 miles in and generally running OK so am at a loss as to what to look at. The spark plug cover is fixed on nicely.

Any ideas?

Thanks in advance.

Can you also try your brown (master) key instead of the blue one.
Maybe your blue key is corrupt and not recognized by the immobilizer.
When you try the blue key, is the red light flashing on the dashboard?
If the red light is flashing 3x and then stays on the key is not recognized.

I've tried the master key but still no luck. The blue key doesn't appear to be corrupt as the immobiliser light does go out once the ignition is turned on.

When I turn the ignition on the ASR/EFI, fuel and immobiliser lights are all lit briefly then go out. The ABS (flashing) and oil lights remain on. I think this is normal but perhaps someone here can confirm?

Thanks again.

Keeping with the simple stuff, try 'wiggling' the starter button (while hold in the brake on, obviously). The contacts on the back of the switches can corrode and it's worth spraying them with contact cleaner.

Also might just be the little switch beneath the brake lever. If you haven't, try squeezing both of the levers...

If it is not the starter or cutout switch as suggested above, nor it is the key then there is a possibility that your ECU has the cutout problem.
According Piaggio, they just released an update for the 2014/2015 gts300 abs/asr facelift versions and will release an update for the 2014/2015 gts300 non abs/asr versions within a month. I'm waiting for this update because I have also the cutout problem. This problem is a familiar gts problem and will be fixed by the piaggio update. My gts300 is just a few days out of warranty but they will update my mapping under warranty. Since your gts300 is 18 months your gts is still under the EU 24 months warranty. Ask your dealer about the details and hopefully they can readout and update your ECU to the latest mapping.

On vespaforum.be (dutch language) they also started a topic http://www.vespaforum.be/index.php?/topic/26646-300ie-super-sport-valt-regelmatig-stil/&page=3 about the cutout problems. This is part of the (google translate) piaggio after sales letter (november 2016). Maybe your problem is related and the gts ECU cuts out even before it has been started.

Dear Sir,
The guarantee we have to shut the system. I just had contact your dealer. They will trim the extension in the system.
Meanwhile it has also become known that a different engine mapping developed by the manufacturer, who must ensure that the problem of stalling completely excluded. It is expected that this mapping will be available within a month. We currently have or already available and can therefore already load on your GTS called Beta mapping.
We assume that among the problems of the past with this approach and you finally be able to enjoy your Vespa.
Sincerely,
Piaggio Vespa BV

With respect, Pilaf, I doubt it's anything like that. Much more likely to be a poor electrical connection on either the starter relay or motor.

Without a multi meter and the knowledge and confidence to trace through the wiring I suspect you've done all you can, Volshafter.

As Pilaf points out, the bike is still under warranty so I would give your dealer a call.

Ok, so the brake lights work.

Now check all fuses, including those under the seat. If those are OK, can you hear the fuel pump prime when you switch on, but before trying to start? If not, then suspect the 'injection loads relay', on the LHS under the seat. If yes, then suspect the starter relay, on the RHS under the seat, or the starter push-button itself.

A multimeter or test lamp is pretty essential for quick and easy diagnosis.

I was just thinking of what happens to me.

The bike is running and I open the seat. It flips up and hits the kill switch. Bike turns off.

It I get some place and open the seat and it hits the kill switch and when I try to start it later it won't.

I think awwwww shhhh, oh it's the kill switch.

@simon64ds your right, any ecu problem comes with the EFI light on the dash and voleshafter is not talking about the EFI light.

Hope you give some feedback when the problem is solved.

Hi all, I really appreciate everyone taking time to share your experience and wisdom. It's what makes this forum so valuable and I learn something new each time. **Thanks**

I'm going to check out the relays as per earlier replies to see if they have worked loose. I'll probably invest into a multi-meter as well. I may well come back here for advice on the readings I'm looking for.

My dealer is not local, and with Christmas on top of us that currently feels like my last resort.

I'll definitely keep this thread updated.

Thanks again!

With photos for reference: -

I have checked the fuses in the glove box and the single fuse in the battery compartment. All appear to be fine. I cannot locate any fuses under the seat - am I missing something here?
When I switch on and before I attempt to start I can hear what I believe is the fuel pump priming OK.
I don't have a multimeter just yet. I have physically inspected the brown relay on the RHS and nothing seems to have worked loose on there. Is this the injection loads relay? When I try to start this unit is clicking/whirring.
I can't locate anything like a relay on the LHS, however there is a white unit (see photo) on the front of the under seat compartment. Is this the starter relay? It's not doing anything obvious when I try to start.
The starter-push button shows no obvious signs of damage/looseness.
The scooter is 18 months old and has just over three thousand miles on the clock. As things stand it's unlikely I can get it to the dealer before the new year so any further suggestions gratefully received. Thanks in advance for any further advice. I can almost certainly lay my hands on a multimeter if needed.

That relay is the starter relay. If that is acting like a buzzer, then your battery is shot, with probably at least one shorted cell. Get that multimeter! The fact the dash lights work doesn't prove a thing about the ability of the battery to maintain 12V while passing the 50A or so of the starter stall current.

This is not an uncommon situation. What happens is that there's enough juice in the battery to get the starter relay to make, but as soon as it does the large stall current of the starter motor pulls the battery voltage below the drop-out volts of the relay, so it drops out. The volts rise with the current reduced, rinse and repeat.

The failing battery can be down to too many short journeys, or being left unused for so long that the battery self-discharges and sulphates. Usually there's no way to resurrect it properly - a new battery is required. The 2015 models have obviously moved that relay somewhere else - sorry, I'm not so familiar with the layout of the newer models. Maplins for a cheap multimeter - new battery from many sources, including Halfords.

I'm inclined to agree with @jimc. With your multimeter on the 20v DC scale connect across the battery. You should get a reading of (at least) 12.5 V. Now operate the starter while observing the meter. If the displayed voltage drops away rapidly then diagnosis confirmed.

One other way to prove (or disprove) the theory is to fit a set of jump leads to a car (or other, known good, 12volt battery).

Fit the red pos (+) leads first then the black neg (-). Be extremely careful not to 'short' anything (allow the red cable to touch anything other than the correct terminal). Now try the starter. If the engine turns then you've proved the point.

Remove the black leads first.

Good luck.

When you say starter relay "acting like a buzzer", it's actually totally passive when I try to start. Unlike the injection loads relay which is clicking/whirring and going through the motions of something. Does that change your view at all on the failed battery? That figures, my commute since I got this scooter has been pitifully short each day.

Thanks again!

Now I'm confused! The brown relay (pic 3 RHS) is the starter one. Put your finger on it and push the starter button. What do you hear/feel?

The brown relay clicks/whirs when I try to start. Does that suggest kanckered battery?

Just about to start with car & jump leads.

Thanks!

Yes. Be careful with the jump leads..

Jump leads have disappeared into a black hole so won't be testing tonight. Will update soon.

You know I won't sleep tonight through worrying don't you?

I have checked my gts this morning and you are correct on the fuse location. I can confirm that there are (on the newer models) no more fuses under the seat, only near the battery and in the glovebox compartment.
See also GTV topic http://modernvespa.com/forum/topic130410

When you completed the tips (battery, relay and fuses) from jimc and simon64ds and still no starting, there are 2 more things you can check.
(Source: http://modernvespa.com/forum/topic134266

First is the ECU MIU G3 cut out feature when the throttle is slightly open.

GTS starts


GTS won't start


I have checked this feature and when I move my throttle just a mm my gts won't start but you can hear the relay sound. So check if there is enough throttle cable slack.

In the topic from above there is another new feature on the 2015 gts, there should be a tip over sensor under the floorboard. On other bikes that switch normally works like a kill switch. Could it be that the sensor is broken.

And finally, you don't have installed a side stand switch, do you?

I have obtained a multitmeter and tested as follows:-

- Multimeter on the static battery reads ~12.6 and when I try to start this drops to between ~11.6 and ~11.9 but still not starting
- I have tried to start with jump leads and the scooter is still not starting..... With the car running the scooter battery reads between ~14.4 and ~14.6

Does this point definitively to a dead battery or perhaps something else?

I haven't yet tried @Pilaf's suggestions regarding cable slack or kill switch.

Thanks all!

Hi Pilaf, I do have a side stand although I never use it. Can you reconfirm where that kills switch/tip over sensor is located - is it underneath?

Thanks!

My GTS reads 12,60 volts static and when the ignition is on it drops with 0,10 volts. After starting when charging it reads 14,50 volts.

Good, we're making progress. 14v with the engine running shows your car alternator is fine

No, doesn't look as though the battery is the problem after all. We need to dig deeper.

The brown starter relay is obviously being fed current because it 'responds' to your pressing the switch. We now need to know if it's feeding current down to the starter motor. You'll need to locate the starter and, with the meter still on the 20V DC scale, put the red probe on the live feed and the black to a good earth (battery neg (-) is good if it t can reach. Operate the starter button and observe the reading on the meter..

This article actually refers to the smaller Piaggio models, but much of it will apply to yours. Have a read and try some of the suggestions.

http://www.pedparts.co.uk/blog/piaggio-gilera-starter-motor-step-by-step-fault-finding

The tip over sensor should be under the floor board.
I have never heard of it but the source is Scooter West so I think its reliable.
See: http://modernvespa.com/forum/topic134266 under "Less obvious"
Maybe it's for the US market only, any suggestions (exact location) about this sensor from other users?

(I just found one on ebay UK http://www.ebay.co.uk/itm/PIAGGIO-VESPA-GTS-IE-SUPER-300-TILT-TIP-SENSOR-/182120104094 so there is a tilt tip sensor, but now the location)

That's unusual - the starter relay buzzing but the battery AOK. I can only surmise that the ECU (which supplies the ground for the starter relay) has a problem, if you've ruled out the 12V supply to the relay.

Have I posted on this thread yet? Hope not... This is way over my head.

To support jimc reply the MIU G3 scheme (pin 10 to starter relay):
(Source: http://members.modernvespa.net/pilaf/uploads/magneti_marelli_miu_g3_information_14854.pdf







Last edited by Pilaf on Sat, 24 Dec 2016 09:39:30 +0000; edited 1 time

Can you check the fuses again, now with your new multimeter, just to be sure.

Another option is to make your own diagnose tool to see if there are errors in your ECU.
I have made a tutorial: http://modernvespa.com/forum/topic150992

At the moment there are 2 ebay UK cable sellers, so if you are lucky they deliver the cables between chrismas and new year.

Whoa! Steady boys! Let's not overthink things. Very, very unlikely to be a fault in the ECU.

Far more likely to be the starter relay or a wiring connection.

It is possible that the starter relay contacts are so pitted that they can't supply the current. This would be evident with the meter test though...

All, I'll be off the grid for a couple of days but I promise to keep everyone posted. Thanks thus far for all your wisdom and suggestions.

Merry xmas.