Auto fill up problem

[alexnev]

First of all I want to say that you guys are selling a perfect product! I really like it so far. Nice and very inexpensive!
I'm using it on my 2010 mazda 5 touring. The protocol is 11-bit can. Device can read fuel level through CAN bus. I verified it through "sender mode" setting.
I'm trying to use "smart" fuel level monitoring. I've set up upper threshold at 95%, low threshold at 50%. I'm using the mode which detects "up threshold". I have filled my tank 5 times and ultragauge did not detect fill up automatically. I had to push up button  to manually inform it about fill up.
I understand that I'm doing something wrong, but I followed manual...
Could somebody help me to proper set up this function?
Thank you in advance,
Alex

[UltraGauge Admin]

Display the "Fuel Level %" Gauge.  This is the output of the sender.  At fill up, compare the value of this gauge to the thresholds you have programmed and adjust accordingly.   Also, after fill-up, UG samples the sender for some 20 seconds before the fill-up is detected.  This is to avoid false triggers such as hard braking or cornering

[alexnev]

Thanks, that was a good advice!
My tank size is 60L (15.85 gallons)
I measured the output of the sensor after fill up and it was 14.8 gallons, which is roughly 93.35% of full capacity. I've had 96% upper threshold set by default, so no surprise ultra gauge wasn't detecting a fill up. I set up upper threshold at 93% and ultra gauge detected fill up. But the thing is, it displayed 14.8 gallons of fuel available instead of 15.85 after fill up detection... after manual fill up instruction (long press up) it showed 15.85 gallons.
Will see if it will work fine after next fill up.
Admin, is it normal?
Thank you in advance,
Alex

[alexnev]

ups...have found an answer in the manual:
"NOTE: When changing the mode from Disabled or Enabled to Smart, UltraGauge will automatically estimate the existing fuel in the fuel tank by using the output of the fuel tank sensor. This is best performed while not moving and on level ground."
I'm good to go!!!! This confirms how good the product is! and How smart are people who wrote the manual in anticipation of users problems...
So I'm going to set low threshold at 35% and up threshold at 92%.
It's funny why mazda's native sensor is so way off....