Yamaha fuel management not working

[southernstyle995]

I have a Yamaha fuel managment for a pair of 2002 f225txra that isnt working. It shows - for gph and mpg. I've check wiring at gauge an at flow sensors an dont see a problem. Do yall think flow sensors are bad? Is there a way to test them? Thsnks

[Silva Bullet]

Replaced one about four years ago and just had another one quit...a friend of mine said he got his to working by flushing it wirh seafoam...may have a little gunk in it. Doesnt take much.

[99yam40]

I never tried it, but a meter set to Hz may be able to read the square wave generated.
a scope should show if it has an output signal