Stelvio Starter Relay Won’t Send Juice

I have the same problem, so would be interested to find out what the issue is.

Dealer has had it about 7 business days. He said he logged considerable time troubleshooting ruling things out, one of which was the ECU, where a substitute was swapped, and bike still didn’t run. He says there’s a number of circuits that ground through the ECU that need to be checked out…..

The most obvious of these circuits is the starter button itself that grounds through an optional antitheft device. I have a single shunt in place of where this device would go-in the tail section, since the antitheft device option is not present. If I’m lucky it will be a bad connector. If it’s a break in the wire inside the insulation and inside the shrinkwrap sheath then there will be added labor…..

I am expecting a breathtaking repair bill.

Engine stopped when riding through rain then wouldn’t start on the button, have you checked your side stand switch?

Yes, the side stand switch was checked.

Amstaff wrote:

Dear Grisologists,

Maybe someone has insight into an issue with my ‘14 Stelvio. What could cause the starter relay to not respond when button is pushed?

Spent most of the day trying to ferret out the common culprits. Fuses, battery, connections and terminals seem to check out. Failed while underway in the rain, coasted to a stop, wherupon the bike would light for a moment but not stay running. Buggered with the main fuses and suddenly after fussing with the fuses behind the right side panel the button wouldnt produce a response. Towed home. This is a low mileage bike not normally in rain, maybe never before, since was bought with 2800 miles, and I’ve never run in the rain. Spends its life in a garage. Instruments cycle on appropriately. SERVICE message comes up at times as does the red triangle. The tail light and the parking light come on with the key.

Test lead to the battery from the spade on the starter makes it run. Swapped the starter relay with the aux light relay, and swapped the Start Up Maint relay with another that seemed identical. No luck. Jumped the violet and violet/yellow leads on the starter relay plug, and the starter turns when the key is switched on.

Is this Starter Interruptus? Seems not given the above. Seems the ECU or something is keeping the starter button from activating the relay.

Trying to avoid the long trip to the dealer and the down time. If they werent 1.75 hours away and could fit it in it would be there tomorrow.

Thanks if there’s ideas on these symptoms.

I posted the original post up here, too far away on page 1



Sorry I came in late but I'm sure Hamlin Cycles will find the problem
Do you have the antitheft device on that model, the start button goes through that to get to the ECU
There's also several other devices interlocked with the start signal Sidestand, Neutral, clutch lever
I assume the fuel pump is doing its thing?
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This bike has what I call the weak yellow feed to the start relays, you can verify that by having someone watch the numberplate light while you try to start but why not fix it properly.

I think we should wait to see what Hamlin Cycles find.

Not sure what you're calling weak yellow feed to the relays. Is this the power feed to the solenoid, or the button signal feed? The starter turns when the starter relay pigtail is jumped with an alligator clip and the key turned, and it actually runs when the starter solenoid is momentarily jumped to the positive battery terminal.

If i ignore that the bike failed while riding, at this point it seems isolated to the starter button and connected circuits…..This is not an easy repair. Never had a bike or a car leave me stranded like this and be so broken that you cant even find whats wrong. I hope I get an answer that restores confidence in the bike.

No I mean the feed to the two Start relays, the Starter Solenoid draws about 50 Amps for a split second while the solenoid is engaging the gear, it has to pull that through the spaghetti wiring. The Startus Interuptus fix takes care of that with a direct feed.
Yes, what would cause the bike to stop once its running, Im fairly sure the injector relay/s must have dropped out killing the power to pump and coils etc.
The only thing I know will do that is if the rotation pickup (50) fails but I doubt that would happen just because of rain.
I assume the pump runs for a couple of seconds when you turn the key On?
You will hear the pump start-up to prime the system but you won't be able to hear it come back on over the engine clatter. a simple bulb will show you that.
"Test lead to the battery from the spade on the starter makes it run". what do you mean by that exactly, Starter cranks or bike will start?

Yes, the fuel pump can be heard when key is turned. The test lead jump from the solenoid spade to the positive battery terminal turns the starter and starts the motor which will run seemingly normal making me think, had I known, could've been ridden home….

Apparently not the normal problem assumed caused by the crappy wiring design overloading parts of it-i.e., Starticus Interrupticus. Bike is practically a time capsule compared to other 2014 bikes.

The start relay can always be jumpered but what is still puzzling, why did the bike stop while it was already running?
Looking at the schematic Injection Relays (30) & (31) must have dropped out turning off power to the pump and coils

The start button on this bike is a little confusing because it goes to several places all it does initially is ground out the wire going to pin 28 of the ECU (this is an input).
The wire to make this happen goes via pin 1 & 2 of the Antitheft Device (60)
The next thing that happens if all the logic inputs are satisfied the ECU grounds out pin 2 of the start relay via ECU output 1, this turns on the relay (3) which is supposed to engage the starter solenoid.
Where it gets tricky is Guzzi provided a second Startup Maintenance Relay (4) this now also closes because it gets 12 Volts from relay (3) pin 5 the start button is still pressed grounding the other side of coil pin 1, the Maintenance relay will keep the starter cranking as long as you hold your finger on the Start button. it overrides any ECU logic.

I would start by removing the battery terminals, scrape and grease those.
Look at the connection for the Antitheft Device, I suspect there must be a dummy circuit card in there jumping out pin 1 - 2 and 3 - 4 make sure the connection is not corroded, especially 3 - 4 those could drop the bike out while running. I would be interested if there are any other pins connected.
Do something about the weak yellow wire, those two relays need a direct feed from the battery via a 20 Amp fuse. I will try and look at a Stelvio later today.

I’ve done all the basic stuff like clean the terminals and check the pigtail with the dummy plug in place of the optional security device. (This dummy plug caps off this branch of the harness and houses a single wire.) I have a MY2011 wiring diagram which may be slightly different than your 2008.

The dealer still has it and spent some hours on it. He has other things to do though……As mentioned previously he has indicated that something is not grounding through the ECU that should be, and swapped the ECU, which ruled that out. At some point I may share this thread with him. Thanks, and if you have time to share additional ideas it is appreciated.

Lovely bike…. If it ran…. With the new top of the line Wilbers and Traxxion Dynamics fork cartridges. All the money in the bike will likely keep me from a new V85, Triumph or T700…..UNLESS IT CANT BE FIXED….Ah ha ha ha.

My GRiSO still runs. Its the only one of the four Guzzis I’ve had that hasnt stranded me with electrical issues.

Kiwi_Roy wrote:

The start relay can always be jumpered but what is still puzzling, why did the bike stop while it was already running?

If I was a gambling man, I'm betting the battery is toast. Sure, it might be a new one, but that doesn't change my opinion.

kiwi dave wrote:

Kiwi_Roy wrote:

The start relay can always be jumpered but what is still puzzling, why did the bike stop while it was already running?

If I was a gambling man, I'm betting the battery is toast.  Sure, it might be a new one, but that doesn't change my opinion.

Good point Dave,
That can be quickly ruled out by jumping from the solenoid spade connector to battery + with the key ON. if it cranks over the battery is probably OK. If it doesn't crank over look closely where the battery is grounded to the chassis.
Measure battery Voltage while cranking, a typical good battery will hold around 10 Volts.
You can check the ground connection by measuring from the battery Negative post to an engine bolt again while cranking, should be less than 1/2 Volt.

Unplug the Startup Maintenance Relay, with your multimeter on Volts with black lead connected to chassis the red lead plugged into pin 1 of the relay socket and the key On you should see 12 Volts coming from the ECU pin 28. If not go back further with the red lead ie pin 2 of the Antitheft Device.
The Start button when pressed should ground out this 12 Volts making it zero.
Note: Computer inputs are often 5 Volts rather than 12 so don't be thrown by that.

Alternately with the key Off and meter on Ohms with the red lead in the relay socket pin 1 black lead to chassis the meter should go from a high value to zero Ohms when you push start.
BTW, I think the bike should start without the Maintenance relay in place, earlier models without the weak yellow feed didn't have one.

The discussion I had with the dealer indicated he had ruled things out to the point where he focused on circuits that ground through the ecu. If I understood him and you correctly, then it would mean he checked that already. That tells me its a bad pin somewhere or a bad wire. Its not starticus interrupticus or a bad battery, or dirty battery terminals, which I could’ve fixed. This is way beyond my skill level which is fairly good, although atrophied since I swap bikes so often.

I’ll share what you described when I talk to him later this week. I appreciate the effort. Thanks.

For the ECU to ground out pin 1 of course the ECU needs to be well grounded, it wouldn't hurt to supplement the one shown with a jumper lead, the only ground shown is to the case, i'm surprised by that, And of course it needs 12 V on pin 17 via the Injection relay and the dummy card in the Anti[theft relay slot.
Getting back to the original stall while running possibly the ECU lost power on 17. I helped one owner who had pinched the cable going to the rear wheel sensor (48). it was shorting out the power to 17
Speaking of which these sensors have a habit of shorting out in wet weather (note the connection) the wire cable is soft and flexible the sensor body is hard creating a path for water to wick into the sensor and short out. A dead give-away would be if you had noticed something wrong with the speedo.
Just last week I looked at a California 1400 that was throwing up ABS codes and the cruise control had stopped working, same thing.
You could easily unplug the sensor at the connector under the tank.
The solution for protecting these sensors is to apply some silicon sealant where the cabe exits, that makes a flexible seal.
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You do know of course, you aren't supposed to ride in the rain eh!

I sent the link to this thread to the mechanic.

Upstate NY had a solid month of rain for July. I know the Itals dont care about rain when they build things cuz it dont rain there.

Traded the bike in and will hear back and post when I know what the fault was-dealer said he’d let me know when he solves the mystery……

Brought home a 2020 V85TT since there was a $2000 factory trade allowance added to the trade value for the Stelvio….

At least you fixed your problem, congrats on a new bike.

Yes, congratulations on the new bike

Don't forget to look at the two speed sensors on it, they will look fine at first glance but if you look under a magnifying glass while bending the cable you might see a tiny crack between the cable and the sensor body, a few minutes to swipe a tiny bit of silicon sealant over that area may save you some grief later on. I believe all the Guzzis use the same speed sensor.
The 1400 I looked at the other day started throwing up sensor errors after a ride in the rain.
The rear one will go first because it gets sprayed with dirty water in the rain, the front gets wet too but it's clean water so not so conductive.

Roy, they don't all use the same sensors. GRiSO uses a small, flat, rectangular one on the CARC bevelbox. Most other models and all the ABS models use a cylindrical one that fits on the front (Right?) fork and another one with a sort of blade that goes in the cast in boss with a hole in it on the underside of the bevelbox casting.

Same principle for both bit different logic as to the signal interpretation.

Seems the folks designing electrical systems at Moto Guzzi like to have any failure affect as much of the system as possible. Why do they keep doing this?

Amstaff wrote:

Seems the folks designing electrical systems at Moto Guzzi like to have any failure affect as much of the system as possible. Why do they keep doing this?

Because 100 years of tradition cannot be wrong

This is a good question.

Imagine: Yamaha quality electrical system on a Guzzi. Don’t dwell on it though.