Faulty Fuel Gauge (Float Type)

[Motormed]

After running my fuel tank low recently (5 miles left on range) the gauge has developed a fault.
First it was showing empty, even with a full tank, then after a few re-fills it started to register, but only showing around half-full (with a full tank).
This is how it's stayed over the last 5 or so re-fills.
My bike is a 2011 model and has the float type sensor, not the pesky fuel strip.
Any ideas anyone please?

 

[botus]

corrosion?

seen some shocking pics on this forum of rust and rot inside the tank - ethanol will be making this the new normal
can you reach with a coat hanger and move it through its range and see what the bikes does ?

year and exact model... ?

 

[Santa-2512]

Rust would be something of a miracle, on a plastic tank , it could however be a holed float

 

[Buckingham]

I've also got a faulty fuel gauge - 2012 1200GS Rallye - (float type 2 wires, not fuel strip) was working ok until I removed the tank to get at some aftermarket lights wiring that I wanted to remove - now I've got a "fuel" error on the display, the yellow triangle is lit and no fuel or range is displayed.
I measured the resistance across the fuel sensor - 68 ohms - I don't think the level sensor is likely faulty, but really I don't know.
I've also disconnected & reconnected the battery a few times with the tank off.
Any ideas where to go next ?
TIA
John

 

[Magwych]

I've also got a faulty fuel gauge - 2012 1200GS Rallye - (float type 2 wires, not fuel strip) was working ok until I removed the tank to get at some aftermarket lights wiring that I wanted to remove - now I've got a "fuel" error on the display, the yellow triangle is lit and no fuel or range is displayed.
I measured the resistance across the fuel sensor - 68 ohms - I don't think the level sensor is likely faulty, but really I don't know.
I've also disconnected & reconnected the battery a few times with the tank off.
Any ideas where to go next ?
TIA
John

On reading this my first thought is that it seems to be related to you disconnecting the wires to the sensor.
First port of call would be to check that you have connected the correct wires back to the tank Next is to look for broken wiring, especially where it exits the connector. Pulling on the wires may have severed the connection.
Do you have access to a GS911 or Motoscan tool ? It would help to identify if the ZFE thinks there is a short circuit or no continuity.
Another though is that maybe the float 8s caught or dislodged when you moved the tank around. Did you stand it on the rear edge whilst you worked on the wiring?
Finally, are you 100% certain that you did not disturb the wires to the tank when you were renoving the wiring ?

 

[Buckingham]

Thanks will check again but already checked the 2 wire level sensor plug at the plug top of the fuel tank, the wires and pins look sound.
I stood the tank flat in it's normal position but yes I guess something might have changed with the float due to the tank being moved off the bike.
Trying to get a GS911 to plug it in.

 

[Motormed]

I have an update on the situation.......
After peering into the filler neck with a torch I found that the fuel sensor assembly had come off its mount on the neck and was sat at the bottom of the tank.

To gain access I removed the side panels and tank covers followed by the fuel cap and inlet.
Using a hooked wire I fished the sunken sensor assembly out and re fitted it onto the filler neck.

Hopefully this will sort it, there was no damage to be seen anyway.
I reckon I could have knocked it off during a re-fuel.
I'll fill the tank on my way home from work tomorrow and see how the gauge reads.

 

[Motormed]

I have an update on the situation.......
After peering into the filler neck with a torch I found that the fuel sensor assembly had come off its mount on the neck and was sat at the bottom of the tank.

To gain access I removed the side panels and tank covers followed by the fuel cap and inlet.
Using a hooked wire I fished the sunken sensor assembly out and re fitted it onto the filler neck.

Hopefully this will sort it, there was no damage to be seen anyway.
I reckon I could have knocked it off during a re-fuel.
I'll fill the tank on my way home from work tomorrow and see how the gauge reads.

Yep, all back to normal now.

 

[slogger 66]

I also have a problem with the fuel gauge on my 2012 twin cam it registers full with 197miles remaining after riding 70 miles from the refill .

 

[botus]

I also have a problem with the fuel gauge on my 2012 twin cam it registers full with 197miles remaining after riding 70 miles from the refill .

you need to understand if its float is attached to the pump or the later better fitment on the fuel filler - they moved it to get it to work better on small tank bikes - I have NOT yet understood if you can buy the bracket...

and then from a post this year it seems if unlucky - or stupid - it can come detached from the filler neck and make up the numbers

https://www.realoem.com/bmw/en/showparts?id=0450-EUR-01-2010-K25-BMW-R_1200_GS_10_0450,0460_&diagId=16_0783

 

[slogger 66]

you need to understand if its float is attached to the pump or the later better fitment on the fuel filler - they moved it to get it to work better on small tank bikes - I have NOT yet understood if you can buy the bracket...

and then from a post this year it seems if unlucky - or stupid - it can come detached from the filler neck and make up the numbers

https://www.realoem.com/bmw/en/showparts?id=0450-EUR-01-2010-K25-BMW-R_1200_GS_10_0450,0460_&diagId=16_0783

Thank you ,it looks like i`ll have to have a rummage inside the tank . I tried to look inside the filler today but couldn`t remove the inner part of it , I stuck a large allen key in and it felt like something was attatched to it . This fault happened a couple of years ago but the fuel gauge suddenly started working normally after a few months .???