Garmin GMI 20

Hi guys, I have a Garmin GMI 20 multi gauge on my boat connected by NMEA 2000 to my Honda 135.
The boat is brand new and only has 12 hours on it so far, but I have noticed the fuel level/ fuel remaining on board figures are out be a fair amount (at one point it said I had used 50L but when I topped it up I put in nearly 80L). The levels are configured correctly with tank size ect. Has anyone else had these issues? Is there an easy fix?
Cheers


mrwinta's picture

Posts: 457

Date Joined: 14/01/10

Same.

Sat, 2017-12-16 01:23

 Hey mate, I have them too networked with a Suzuki 175. Mine are also a bit out where after filling with 180 liters I will run out with 20-30L still showing.. I don't know how to recalibrate but I think it is more common than you would think.

I will follow this thread with interest.

 

Good luck

____________________________________________________________________________

 NEVER PUSH YOUR GRANNY WHEN SHE'S SHAVING

ranmar850's picture

Posts: 1959

Date Joined: 12/08/12

Thats a worry

Sat, 2017-12-16 07:54

 I had one of those Lowrance LMS fuel flows and gauge on a previous boat. 175L  with no gauge and gunwhale fill.  But it always overestimated fuel flow, no matter how often i recalibrated.  So i always had more in there, not less. After about 600 litres of use, when it was showing empty, you'd have 40 litres left in it. Used to empty completely and reset twice a year.

I would have thought that the 175 Suzuki would be reading fuel flow off the ECU, and calculating fuel remaining  from that, so would have been very accurate?  Have you tried searching THT on this? if it hasn't been discussed on there, it doesn't exist.

mrwinta's picture

Posts: 457

Date Joined: 14/01/10

GMI

Sat, 2017-12-16 08:35

 Its a job I have just never gotten round to.. I always make sure I have enough when I go out but yes you are probably correct the ECU is doing the clever bit.. I would think there would be a way of entering a correction facor into the GMI 20 to bring it more in line with real usage.

____________________________________________________________________________

 NEVER PUSH YOUR GRANNY WHEN SHE'S SHAVING

Posts: 48

Date Joined: 02/06/17

 I would be less concerned if

Sat, 2017-12-16 15:13

 I would be less concerned if it overestimated but as it is it's always on your mind. I always carry a lot more fuel than needed but it'd be nice if it was easier to monitor usage. It is calculated directly from ecu so you would believe it to be accurate but as stated it is a fair way off.

Posts: 3

Date Joined: 10/02/18

 This is easily fixed you

Sun, 2018-02-11 15:16

 This is easily fixed you need to do a system update on the Garmin website for Gmi 20 

i ran out of fuel and it said I had 75ltrs onboard and the problem was whilst traveling at a constant cruising speed the unit would freeze hence using more fuel then recorded

Posts: 48

Date Joined: 02/06/17

Thanks for the info, do you

Sun, 2018-02-11 17:56

Thanks for the info, do you know what update version you have? Has it been accurate since the update? Cheers

Posts: 3

Date Joined: 10/02/18

.

Sun, 2018-02-11 20:06

 No but I just do all updates every 3 months now to get rid of any bugs. If you do a update it should fix the problem

Posts: 3

Date Joined: 10/02/18

 And yes it’s been very

Sun, 2018-02-11 20:07

 And yes it’s been very accurate since 

 

 

Posts: 48

Date Joined: 02/06/17

Thanks for your help mate, I

Sun, 2018-02-11 21:14

Thanks for your help mate, I will try the latest update.

Posts: 48

Date Joined: 02/06/17

I have finally received the

Sat, 2018-03-10 20:08

I have finally received the Garmin network updater (NMEA2000 SD card reader) ready to do the update, but on the Garmin site it says there are 2 different update bundles. The GPSMAP and the LEGACY GPSMAP. Do I need to download both? They both list the same software revision number?
Cheers

ranmar850's picture

Posts: 1959

Date Joined: 12/08/12

Legacy normally means older

Sun, 2018-03-11 08:18

 All manufacturers refer to their obsolete stuff as legacy--sounds nicer---so likely the other package, if it is a current unit.