Electrical Gremlin in my GRiSO

Hi guys,

I bought my pretty GRiSO last year, And there has been a series of electrical issues since.

1.) (After having it two weeks  ) Rolling along on the freeway and the bike stalls, come to find out the dummy light (gas light) doesn't work. End up taking it to the dealer (A Triumph Dealer) to correct.
2.) While i'm at the dealer, the low engine oil pressure light turns on. Tech determines the bike is fine, but that I should just replace the fuel level sensor and the engine oil pressure sensor.
        a.) I rode the bike home, when I stopped to get gas, the engine oil pressure light turned off, all is normal.
        b.) Dealer I bought it from supplies documents showing that the fuel level sensor was recently replaced.
3.) Start of this season, go to start her up and no crank, find out this time the neutral light isn't illuminated. Put the kick stand up, starts fine.
        a.) During a short ride, I notice the neutral light is now coming on.
4.) Speedometer reads 0MPH while in motion.
        a.) Currently active, has not "fixed itself".

I don't believe in coincidences, its rare that so many sensors would "fail" in a 7 month period within 1,000 miles.

So since the speed sensor & harness is easily accessible, I checked it out and I was stopped at the second step:
1.) Check correct position of the sensor in it's fitting - Yes its properly installed
2.) Check voltage between PINS 1-3 (Supply and Ground) In case of Null - STOP, well its not null, it reads 109.8mV. Is this indicating a wiring issue?

The main reason i'm doing this myself is that Guzzi's aren't super popular in Michigan, and the closest dealer is almost an hour away from me.

I know the previous owner took good care of it, the bills I have amount to ~$5,000 since 2016 (Rollerized it, brakes, valve checks, fluid swaps, gasket replacements etc), and I love this thing I wanna keep it forever.

Halp.

EDIT - Spelling error.

All of those sensors have been known to fail.
The tank level could be a faulty ground
Carl's Drawing for reference.
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1) The tank level sensor is either a magnetically operated reed switch or thermistor type sensor, both are dead reliable, perhaps you have a missing wire to the tank.
You can easily test (30) & (31) wiring just with a ground jumper.

2) I have given up on the oil pressure switches, they are just a poor design IMHO as an Instrumentation consultant. I have had 6 Guzzis and the GRiSO one is the only one still working,
The pressure sensor is too tiny to operate the contacts reliably, some owners substitute a larger automotive one but I prefer to add a pressure gauge

3) Scratch around the gearbox and you will find the Neutral sensor, you should be able to inspect the connection, you can ground the wire to confirm the wiring is ok

4) The speed sensors have a habit of wicking moisture into the body, where the cable enters the hard epoxy is a natural entry point it should be sealed with a silicone sealant the first thing I did when I got my 07,  have seen $700 pH sensors suffer the same fate, simply sealing with silicone makes them water tight. You may be able to dry it out with a couple of days bin a warming cupboard.
The good thing about these sensors is they are so easy to test, the switch wire will toggle between negative and positive as you slowly rotate the wheel. It will never go all the way Positive or Negative, the sensor uses some Voltage to set up the electronics. the speedo is probably set to toggle around mid range
here's another thread on the subject.
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Tell me, does your bike spend much time in the wet, I reside in the pacific North Wet so I take precautions with my wiring I usually just the apply of Vaseline to all connections but I keep it indoors when not riding so it gets to dry out and I don't have many problems.

Kiwi_Roy wrote:

All of those sensors have been known to fail.
4) The speed sensors have a habit of wicking moisture into the body, where the cable enters the hard epoxy is a natural entry point it should be sealed with a silicone sealant the first thing I did when I got my 07,

Just make sure the silicon you use use doesn't have that 'vinegar' smell, which is acidic and will corrode copper/electronics eventually. Be sure to use a non acidic silicon such as the blue coloured automotive silicon brand name 'Hylomar' or similar.

As a electronics tech I've had to repair the damage that the 'vinegar smell' silicon caused to electronics that it was applied to 'protect'.

techman-001 wrote:

Kiwi_Roy wrote:

All of those sensors have been known to fail.
4) The speed sensors have a habit of wicking moisture into the body, where the cable enters the hard epoxy is a natural entry point it should be sealed with a silicone sealant the first thing I did when I got my 07,

Just make sure the silicon you use use doesn't have that 'vinegar' smell, which is acidic and will corrode copper/electronics eventually. Be sure to use a non acidic silicon such as the blue coloured automotive silicon brand name 'Hylomar' or similar.

As a electronics tech I've had to repair the damage that the 'vinegar smell' silicon caused to electronics that it was applied to 'protect'.

Thanks for that I never thought it would be acidic not being water based, you don't see silicon advertised as Electrical friendly in the hardware store but it will stand up to water immersion.
I have been using General Purpose GE brand to seal electronic enclosures and convert spoked rims to tubeless, some of the other brands won't even stick to Aluminium,

Kiwi_Roy wrote:

techman-001 wrote:

Kiwi_Roy wrote:

All of those sensors have been known to fail.
4) The speed sensors have a habit of wicking moisture into the body, where the cable enters the hard epoxy is a natural entry point it should be sealed with a silicone sealant the first thing I did when I got my 07,

Just make sure the silicon you use use doesn't have that 'vinegar' smell, which is acidic and will corrode copper/electronics eventually. Be sure to use a non acidic silicon such as the blue coloured automotive silicon brand name 'Hylomar' or similar.

As a electronics tech I've had to repair the damage that the 'vinegar smell' silicon caused to electronics that it was applied to 'protect'.

Thanks for that I never thought it would be acidic not being water based, you don't see silicon advertised as Electrical friendly in the hardware store but it will stand up to water immersion.
I have been using General Purpose GE brand to seal electronic enclosures and convert spoked rims to tubeless, some of the other brands won't even stick to Aluminium,

Vinegar is commonly used as it prevents the silicon from curing, hence that 'vinegar' smell as the vinegar evaporates allowing the silicon to cure.

Just make sure whatever silicon you use doesn't have that pungent vinegar smell and you should be ok. The blue colored 'Hylomar' silicon (usually found in automotive parts suppliers for instance) doesn't have that smell and doesn't corrode copper wiring.

A strange set of issues, for sure. Can you clarify some points, as follows?

Quote :

1.) (After having it two weeks  ) Rolling along on the freeway and the bike stalls, come to find out the dummy light (gas light) doesn't work. End up taking it to the dealer (A Triumph Dealer) to correct.

Question: Does the gas light work properly now? Was a new sensor the cure for that?

Quote :

2.) While i'm at the dealer, the low engine oil pressure light turns on. Tech determines the bike is fine, but that I should just replace the fuel level sensor and the engine oil pressure sensor.
        a.) I rode the bike home, when I stopped to get gas, the engine oil pressure light turned off, all is normal.

Question: Do you mean the oil pressure light has been illuminating when you first turn on the ignition, and then has gone out normally, every time you have started up since then? (If so, a single instance of a false warning light could have been caused by revving the motor immediately after starting, before the oil pressure has had a chance to rise.)

Quote :

3.) Start of this season, go to start her up and no crank, find out this time the neutral light isn't illuminated. Put the kick stand up, starts fine.
        a.) During a short ride, I notice the neutral light is now coming on.

Question: Do you mean it was coming on at inappropriate times while you rode, or do you mean that it began to work correctly as you shifted in and out of neutral, and has continued to work correctly since then?

Quote :

4.) Speedometer reads 0MPH while in motion.
        a.) Currently active, has not "fixed itself".

So since the speed sensor & harness is easily accessible, I checked it out and I was stopped at the second step:
1.) Check correct position of the sensor in it's fitting - Yes its properly installed
2.) Check voltage between PINS 1-3 (Supply and Ground) In case of Null - STOP, well its not null, it reads 109.8mV. Is this indicating a wiring issue?

Question: Are you reporting the measured voltage from the wiring harness connector after it has been disconnected from the sensor's wires, or while it is connected to them? If the latter, have you tried observing the voltmeter while you rotate the rear wheel by hand?

I hope clarifying some of these points can help the group diagnose your problems.

Moto

Hey all, sorry for the late response!

Kiwi_Roy wrote:

ell me, does your bike spend much time in the wet,

I baby this bike since they're uncommon in the U.S. It may have seen damp pavement last season, but I've been pretty careful about not riding in the rain.

moto wrote:

Question: Does the gas light work properly now? Was a new sensor the cure for that?

I'm honestly not sure, last time I found out it didnt work, I had to push her about two miles in 90 degree heat. Haven't been brave enough to test again. When I took it to the dealer, they said the wiring looked okay, but I'm not sure I trust the tech. They said they had just replaced the fuel level sensor.

moto wrote:

Question: Do you mean the oil pressure light has been illuminating when you first turn on the ignition, and then has gone out normally, every time you have started up since then? (If so, a single instance of a false warning light could have been caused by revving the motor immediately after starting, before the oil pressure has had a chance to rise.)

It only happened that one time. They only time I really rev the bike up is when i'm merging onto the expressway. I'm rather gentle with this bike as I don't quite trust it yet.

moto wrote:

Question: Do you mean it was coming on at inappropriate times while you rode, or do you mean that it began to work correctly as you shifted in and out of neutral, and has continued to work correctly since then?

Let me clarify. When I first started the bike the neutral sensor didn't work when the bike was in neutral. I shifted through gears a couple times, with no success. I noticed it started working again when I was trolling around on the city streets when I shifted into neutral.

moto wrote:

Question: Are you reporting the measured voltage from the wiring harness connector after it has been disconnected from the sensor's wires, or while it is connected to them? If the latter, have you tried observing the voltmeter while you rotate the rear wheel by hand?

Yeah I measured the voltage through the harness when it was unplugged. Unfortunately I don't have the ability to get the rear wheel off the ground to see if the sensor works.

Kiwi_Roy wrote:

ell me, does your bike spend much time in the wet,

I baby this bike since they're uncommon in the U.S. It may have seen damp pavement last season, but I've been pretty careful about not riding in the rain.

Its cooling down here again in Michigan (we're expecting snow this weekend ) But I'll go out there disconnect the battery and see if that at least resets the service message on the LCD.

Part of me hopes it "fixes" itself, maybe that will help narrow it down as an intermittent short to ground/voltage?

Tom

Have you checked the OBD to see what error code is throwing up the service warning? That at least gives you a starting point.

ShadowsJudgment wrote:

Hi guys,
4.) Speedometer reads 0MPH while in motion.
        a.) Currently active, has not "fixed itself".
...
So since the speed sensor & harness is easily accessible, I checked it out and I was stopped at the second step:
1.) Check correct position of the sensor in it's fitting - Yes its properly installed
2.) Check voltage between PINS 1-3 (Supply and Ground) In case of Null - STOP, well its not null, it reads 109.8mV. Is this indicating a wiring issue?

Hi Tom,

You should find 12 volts between the hot wire and the ground wire of the connector for the vehicle speed sensor, when it has been disconnected from the sensor. The ignition switch and the run switch on the right handlebar must be ON for this test.

If you don't find 12 volts, either the supply circuit (which comes directly from the run switch, according to the wiring diagram), or else the ground circuit must have a fault.

To test these possibilities, connect your voltmeter between the hot wire pin of the connector and the negative battery terminal. If the fault is in the supply circuit, you should still read the same very small voltage between it and the terminal. If the fault is in the ground circuit, you should see 12 volts. If you have marginal results, try turning the run switch on and off several times, or measuring resistance through it when it is in the ON position. You need to find some way to get 12 volts at that connector.

Your other symptoms don't fit any pattern that I recognize. In particular, they don't seem like symptoms of dashboard failure.

Thanks for clarifying your earlier message. Maybe that will help others help you.

Moto

Helping a Breva owner I used my 07 GRiSO 1100 to take these readings
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Note: I didn't find the Positive pin 1 at 12 Volts, only 10 so it may be different on the 8 Valve

Just an update! Sorry for the radio silence, life has been crazy.

I tested the wires and everything checked okay. I ended up taking to a local Guzzi dealer (Detroit Iron).

They had it for about 5 months and couldn't reproduce anything unfortunately. Did take care of all the maintenance items though. Since they couldn't reproduce anything they thankfully didn't charge anything.

The guy who worked on it had thankfully worked on it before and mirrored what you guys have said here, for the oil pressure sensor we need to install a spade type connector to correct the intermittent low pressure warning.

As for the other ones he wasn't sure, possible that the speed sensor had moisture in it that had since dried up. Fuel level sensor checked fine.

Took it home and decided to take the battery out for the rest of the winter. And behold, on both battery terminals, corrosion.

And a leaking battery.

Scrubbed the terminals and got a new battery. We'll see what happens in the spring!

Fingers crossed.

Tom

ShadowsJudgment wrote:

Hi guys,

[You must be registered and logged in to see this link.] And there has been a series of electrical issues since.

1.) (After having it two weeks  ) Rolling along on the freeway and the bike stalls, come to find out the dummy light (gas light) doesn't work. End up taking it to the dealer (A Triumph Dealer) to correct.
2.) While i'm at the dealer, the low engine oil pressure light turns on. Tech determines the bike is fine, but that I should just replace the fuel level sensor and the engine oil pressure sensor.
        a.) I rode the bike home, when I stopped to get gas, the engine oil pressure light turned off, all is normal.
        b.) Dealer I bought it from supplies documents showing that the fuel level sensor was recently replaced.
3.) Start of this season, go to start her up and no crank, find out this time the neutral light isn't illuminated. Put the kick stand up, starts fine.
        a.) During a short ride, I notice the neutral light is now coming on.
4.) Speedometer reads 0MPH while in motion.
        a.) Currently active, has not "fixed itself".

I don't believe in coincidences, its rare that so many sensors would "fail" in a 7 month period within 1,000 miles.

So since the speed sensor & harness is easily accessible, I checked it out and I was stopped at the second step:
1.) Check correct position of the sensor in it's fitting - Yes its properly installed
2.) Check voltage between PINS 1-3 (Supply and Ground) In case of Null - STOP, well its not null, it reads 109.8mV. Is this indicating a wiring issue?

The main reason i'm doing this myself is that Guzzi's aren't super popular in Michigan, and the closest dealer is almost an hour away from me.

I know the previous owner took good care of it, the bills I have amount to ~$5,000 since 2016 (Rollerized it, brakes, valve checks, fluid swaps, gasket replacements etc), and I love this thing I wanna keep it forever.

Halp.

Tom

EDIT - Spelling error.

I have been pondering over this for a while then I had a brain fart.
I find it interesting that the 5 sensors you list (30) Oil pressure, (31) Neutral Switch, (33) side stand switch, (34) Fuel Level Sensor & (48) Speed Sensor  have different ways of communicating to the bike
(30) Oil Pressure via the Dash terminal 17
(32) Neutral Sensor via the ECU terminal 23    At one point the bike was in Neutral but the Dash not indicating
(33) Sidestand Switch via ECU terminal 38       At one point the side stand was deployed but the Dash was not indicating so
(34) Fuel Level Sensor via Dash terminals 9,18
(48) Speed Sensor via ECU terminal 24            The Speed Sensor looks OK but speed is not showing on Dash
_______________________________
Now (32), (33) & (48) enter via the ECU but their status is displayed on the Dash, how does the information get from the ECU to the Dash, I think via the single wire from ECU term 7 to Dash term 6 known as  a "Data Highway"
This information is transferred in a digital format typically in a format known as Canbus
Note: this "Data Highway" also branches out to the Diagnostic connector (12)
I'm wondering if there is possibly something wrong with this communication link, perhaps a loose contact or even a short perhaps in the diagnostic connector wherever it is.
(32) & (33) would effect the running and starting even though the Dash is not displaying their status
I think the Dash would display the last known good status.
The Fuel Level Sensor (34) is the one that doesn't support my theory but it might be really bad, very easy to check with an Ohmmeter or by shorting out the wires to test the dash.
-------------------------------------------
I used to work with industrial controls in petrochemical plants, critical interlocking is not allowed over a data highway, even in this simple motorbike several of the sensors are wired direct to the ECU
where they can shut down the motor if need be.

Yeahhhhh. My first instinct was an issue with the canbus since 5 sensors were acting up within a relatively close time frame, I’ve seen this kind of stuff on some FCA vehicles with pinched / chaffed main harnesses.

When it warms up here in Michigan a bit, I’ll poke around the harness and let you know what I find.

Fingers crossed.

Tom

Last week I was helping an owner with a Stelvio (almost identical wiring), it was displaying symptoms very similar to your bike.
He also noted that the fuel pump had stopped priming when the key was turned on.
I walked him through checking into why the pump wasn't working he found the fuse feeding the Main Injection Relay (F4 in your case) was blown, replaced and blew again as soon as the key was On.
This fuse feeds 12 Volts through the Main Injection Relay to a number of very important loads.
Coil of Secondary Injection Relay - the contacts of this relay in turn feed the fuel pump, Injectors and coils - Critical
Feed for Kill Switch - lets the ECU know its ok to run - Critical
Lambda heater - not essential for running
Speed Pickup - probably the most vulnerable wiring on the bike - not important
Start Relay coil - only needed for starting
ECU pin 7 - I suspect this is required to be on at all times
I asked him to unplug the Lambda sensor thinking it might have a short in the heater and also inspect the speed sensor cable, sure enough he found a spot where the sensor cable had become pinched while he was mounting the rear wheel. He repaired the cable and of course the bike now runs.
You might have an intermittent short, not enough to blow the fuse but enough to pull the Voltage low for a second or so,
I would unplug the Lambda and the speed pickup cable see if that clears it up. Your Speedo is not working so that's another red flag.
The speed pickup is not important in itself but the cable can take out the bike if it shorts 12 Volts to ground (chassis), it should almost have a small 1 Amp sub fuse.
I did a sketch showing the start sequence and how the start signal ripples through the wiring from turning on the key until the starter engages and another of just the 12Volt loads on Fuse 4.
I would post the sketches here but my Mac is refusing to play ball, If you send me a cellphone No in a PM I will text it to you.