Fuel gauge not working after private sale

facade

On a lot of "modern" cars the fuel level sensor is part of the fuel pump assembly, presumably to make it easier to build, and dearer to maintain, as no doubt you have to buy the whole thing.

However, as the "miles to empty" is working it sounds as though the level sensor is working and the problem is at the dashboard end.

ess0two

The fuel tank has a left and right sender these can be accessed via the hidden menu on the dash,or an aftermarket OBD program to see whether they are reading correctly.

arcon5

No the fuel pump doesn't read the level. Often an in tank pump has a sender unit as part of it (typically in the form of a float and a variable resister) but the pump reads nothing. Especially since many cars still have inline pumps and many diesels will actually have a lift pump build in to the high pressure pump!

Nickyg

Thanks all. Car is 2005 630i, I'll see if I can get into this secret dashboard menu. The petrol gauge is actually stuck on a quarter left, so I wonder if something has got stuck somewhere I.e it's not just sitting on empty and not moving up. I'll let you know but thanks for all the good advice!

Iceweasel

Nickyg wrote: »

Thanks all. Car is 2005 630i, I'll see if I can get into this secret dashboard menu. The petrol gauge is actually stuck on a quarter left, so I wonder if something has got stuck somewhere I.e it's not just sitting on empty and not moving up. I'll let you know but thanks for all the good advice!

Be careful - especially if you are new to BMWs.

The hidden menu is hidden for a reason - to stop people interfering with settings and options they do not fully understand.

The info it gives is invaluable - but make sure you have read as much as possible about it before having a look, and perhaps inadvertently change things.

It is possible to do a check making all the gauges swing from minimum to maximum for example.

Here might be a good starting point to find out how:

https://www.youtube.com/watch?v=envKMwftf6w


But the guys on BMWLand will keep you right.

Nickyg

That swinging gauges from min to max was what I wanted to try. I'm not getting involved with the codes side of things as I'll no doubt make it worse

Nickyg

I did the hidden menu check on the dashboard dials and they all moved except the fuel gauge so definitely something not quite right there.

colino

That actually sounds like a good result. As you are still getting "miles to go", the ecu is getting both average mpg and whats left in the tank, so at least some of the wiring and tank gubbins is OK and the needle sweep is pointing towards a duff gauge (indicator).
Have a look on bbareman and see if the cluster is a common fail/fix and with any luck it isn't like the "clever" earlier ones that had two senders to accommodate the saddle shaped tank.

facade

You have tried tapping the glass in front of the gauge like we used to in The Olden Days?

Nickyg

Drove home tonight and the needle has actually moved a bit towards half full which is odd, but it still isn't right.

Haha, no, tapping the glass didn't work