Tach or sensor problem?

[lucian]

Tach on my 09 griso started dropping to 500 rpm and now down to zero when bike is hot, even though the actual as engine idle seems the same, around 1000 rpm. My guess is the sensor can't take the heat, is there a way to test it? Bike runs great other than a slight hesitation when dead cold. tia    Dave

[guzzisteve]

I would unplug the dash and clean up contact pins, could just be a bad connection.

[pauldaytona]

the rpm's come not from a sensor, but from ecu. That sends it over the can bus.
Looks like the dash is bad. But getting the connetor one out and in , well you never know.

[Vasco DG]

Tach gets its signal from the phase sensor, I think via the ECU but I'm not sure. If the phase sensor was going dicky I'd expect you to loose spark too.

Pete

[Wayne Orwig]

When you first turn on the key, does the tach go through the full self test sweep?

[lucian]

Yes the tach does it's sweep on start up and when it drops down at idle it still responds when you blib the throttle. Seems to operate normally other than at idle when hot. And when you shut the ignition off and restart, it shows 1000 rpm again. Please don't tell me this is guzzi character.