4" Gauge , wrong display

[tomille3]

Hi
On my boat I have two 4" Suzuki multifunction gauge
I did the fuel tank calibration (155 liters)
the tank is full

on the gauge I put 2 different fuel remaining source

The first one (fluid level sensor) is showing 155 liters which is correct .
The second one (Engine/ FFlow) is showing 158 liters which is wrong . If I change the remaining source as it is OK (155 liters)
(I already did many fuel tank unconfigure then configure, then tank calibration ..etc)

What should I do to get 155 liters with "Engine /Fuel Flow" as remaining source ??

From those two remaining fuel source , which one is best or the more accurate ??

thanks

[Harper]

As I understand it, you've calibrated the fuel level, using either the 2 point, 3 point, or 5 point calibration method, as explained on pgs. 52-53 of the manual (the 5 point method being the most accurate of the three).

Have you also done the fuel flow configuration and calibration as per pgs. 44-45? To do so will require that it be done when you refill the tank.

One reading is not necessarily any more accurate that the other. If the fuel remaining is based on the level reading of the fuel level sensor, then accuracy depends greatly on the shape of your tank. The fuel remaining based on fuel flow is dependent on the volume of fuel at a standardized density according to the accuracy of the software in the ECM, which calculates it based on the injectors dwell (duration) times.

One last observation....a difference of 3 liters out of 155 is minuscule, well within an acceptable margin of error. I don't know that you can expect any better accuracy than the <2% that you are talking about. You certainly don't want to be pushing your luck on the open water to the point that 2% would make a difference on whether or not you made it back to port.

[tomille3]

Yes I follow the step as per the manual
Of course 3 liters is peanuts
But why does it showing me 158 liters ? I enter a 155 liters tank
I enter that the tank is full , so it should showing me 155 ??

The perfection doesn't exist , but I like to be as close as possible !

[Harper]

Yeah, I get it. I don't have an answer to your question. I use the fuel flow as source, and I've configured my tank as a 60 gallon tank. When I indicate that I have refilled, it always shows 59.7 gallons. Dumb gauge doesn't think I can get 60 gallons in there. Nothin' in this world is perfect, my friend, not eben my tuyping.....

[tomille3]

on the same gauge when I select fluid level sensor , so it appear 155 liters remaining. OK
If I put back Engine F Flow as remaining source it show 158 !!!

[Moonlighter]

I can only suggest you go into the boat setup menu and set the fuel tank size there as 155 liters. If you have already done that it must be something weird.....

I understand that there can be conflicts when you have both fuel level and fuel remaining (calculated from engine ECU). So it might be one of those situations. It does sound very strange.

Maybe check the interface software and the SMIS software versions and then give Lowrance customer service a phone call when you are sitting in front of the gauge. They might be able to tell you if it is a software conflict issue.

Also get them to talk you through the fuel tank size setup to make sure you are doing it correctly.

The Suzuki 4" SMIS gauge is basically the same as a Lowrance LMF400 so they should be able to help you.

[tomille3]

Finally I did a complete reset , I re installed the firmware then I enter all parameters.
It's OK

Strange ...... But OK