What does this button on my throttle do?

[Eric Pride Mitchell]

New here as of today. I have an issue with erratic trim (as indicated by analog gauge) and surging speedometer. The result is non critical warning for low voltage. I know trim adjustment pulls a lot of amps. I think the tiny button in front of the up/down trim thumb rocker switch on my throttle is somehow involved, but I can't find anywhere what it does. Is it a trim limit bypass button of calibration button?

 

[Espos4]

New here as of today. I have an issue with erratic trim (as indicated by analog gauge) and surging speedometer. The result is non critical warning for low voltage. I know trim adjustment pulls a lot of amps. I think the tiny button in front of the up/down trim thumb rocker switch on my throttle is somehow involved, but I can't find anywhere what it does. Is it a trim limit bypass button of calibration button?
View attachment 133295

That is the throttle lever for a DTS equipped engine. There is no limit switch for the trim like a conventional throttle lever has, aka a “trailer” button.

I believe that is just a cover for a screw. That “button” doesn’t do anything.

An erratic trim gauge may be caused by faulty trim position sensor on the gimble. There are 2 “hockey puck” looking things mounted over the gimble ring hinge pins. One side is a dummy, the other side is your trim position sensor.

Do you have a Smartcraft user manual? There is a procedure to recalibrate the trim gauge in there. It is available as a PDF if you google search it.

The smartcraft system with DTS is very sensitive to low voltage. A low voltage warning with the engine running is a clue that something isn’t up to snuff.
Old batteries
Dirty or corroded connections
Weak alternator
Loose drive belt
Just to name a few.

Give the electrical system a good once over and address any issues before things get worse.

You may also have a tag on one of your wires like the photo attached. Check that too.

 

[Lazy Daze]

In addition to the above - or to add to it, anyways...

This is incorrect logic: "The result is non critical warning for low voltage". Low voltage is not a result. The "result" would/could be the issues you are having. As noted, start by addressing the reason for the low voltage.