6Y8T-11 Command Link Tach don't show RPM

[SWETobbe]

Hi, I have a 30 HP Yamaha from 2017 with a Command Link Tach (6Y8T-11) and it has been working perfectly since I bought it, but last week it stopped showing the RPM. The display only reads a "-"-symbol.
I have google and found several others that have the same problem but no solution. I now hope someone here can help me.

I didn't do any service on the outboard when it stopped. The Tachometer lights up when the key is turned and shows other information so the connection should be ok.

Unfortently I don't have any other instrument to try to get the information.

[fairdeal]

The Tachometer lights up when the key is turned and shows other information so the connection should be ok.

I agree;
the rpm comes as part of a data stream from the ECM,
along with trim, temperature, voltage.
If the gauge is receiving any of it, it is receiving all of it.

And the ECM certainly 'knows' what rpm the engine is turning.

Very puzzling.
I can imagine no other cause,
but an internal failure of the operation of the ECM.
I would be very interested to see what the YDS interface displays for rpm...

[boscoe99]

Are you saying that all other information is being normally displayed while the RPM info is not?

[SWETobbe]

After some more investigation it turned out that water had got in to to instrument. I called the store that sold me the Yamaha outboard and they sent me a new Tach. Now everything works.