Stelvio Speedo

[Doug McLaren]

Hello. I was wondering if anyone here can shine a light on the problem I'm having with the speedo on my Stelvio.

A couple of weeks ago the speedo stopped working and the ABS light came on when I was on my way to work, on the way home it suddenly started working again as I was riding.
I took the sensor out, cleaned it and checked the connection under the seat, the next day after stopping for fuel it went off again and the ABS light came on, only this time I got the red triangle and the service warning. When I got home I rechecked the connections and using Guzzidiag cleared the fault. The speedo then worked for a few miles but after stopping at a friends house and upon setting off again, no speedo ABS light lit up and red triangle along with service indicator appeared.
So I bought a 2nd hand sensor, bunged it in, cleared the fault and this morning set off for a ride around Northumberland. Speedo worked fine but again after stopping and restarting it went off and ABS, red triangle and service warning appeared.

It seems strange that the speedo works at first then only stops working after I've switched the ignition off and then restarted the engine.

Anyone else had similar symptoms?

[PJPR01]

I’m guessing it’s the front wheel speed sensor that is causing the issue, perhaps a frayed wire to that sensor.  Had the exact same issue on my Norge a few years ago, spliced and reconnected the wire and all of the same errors you are having went away.

[Kiwi_Roy]

If it's like the usual Guzzi sensors its not waterproof, the cable is potted to the sensor with hard epoxy the cable is soft so it looses contact allowing posture to wick in and short out the solder joint where it attaches to the cable..
To fix this take it off and dry it for a few days in a warm place then smear silicon around where the cable exits.
The silicone is flexible so it won't loose it's grip on the cable.

I learnt this from working on expensive industrial probes, a few drops of water would render them useless but after the silicone treatment we could drop them straight in a tank.

[Doug McLaren]

Thanks for the replies, I've had a good look at the sensor, there are no apparent cracks in it and it's been very dry here for the last week or so. I've cleared the error again and the speedo is reading when I spin the wheel, I'll use it tomorrow for work and see what happens.

Thanks again.

[Kiwi_Roy]

I never said crack,
If you bend the lead coming out of the sensor you will see it parts company with the epoxy, capillary attraction will wick the water right in there.

It was top priority to seal it when I bought my Griso

It does rain where you are?

Wait until its nice and dry before sealing it, don't want to lock the water in.
It's a common fault with the Guzzis with electronic dash, Brevas on up.

[Doug McLaren]

It does indeed rain here but I didn't use the bike at all over the winter and the fault appeared a couple of weeks after I started using it again. I've only been caught in the rain once this year and that was last weekend on the way back from Scotland, the fault had appeared the day before, in the dry, only after stopping for a few minutes and starting off again.

I'm not entirely convinced that it's the sensor as I've already swapped it for another, and yes I realise the replacement could be a duffer also but the later ones as fitted to my bike are supposed to be better for sealing against moisture , or so I've read.

An odd thing happened while I was poking around the harness. The ABS light is supposed to flash then go out when you start moving, if there's a fault it shines constantly and the speedo reads, and stays on, 0 mph. I cleared the fault and had the speedo registering a few mph whilst turning the back wheel. Now there's a section of the loom where the sensor wires run, it's just behind the fuses under the right side of the seat and is kinked quite severely to clear the frame,  I could sometimes get the ABS light to come on constantly while manipulating the kinked part of the harness. Of course it happened only a few times and I couldn't get it to re-occur. I believe it's not uncommon for problems in the routing of harnesses to show up after a few years when cables and connectors have had time to chafe or corrode.

I thought maybe someone else might have had the same problem.

[pete roper]

Doug, have you checked and sealed/replaced both wheel sensors? A problem with either of them will cause dashboard or abs light issues.

Pete

[Doug McLaren]

Well what a dummy!

I never thought to have a look at the front sensor. It's 7am here and I'm off to work in 15 mins or so. I'll see how it behaves today and have a peep at the front sensor this evening.

Cheers Pete.