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2002 E46 318Ci - Fuel gauge not working

27K views 29 replies 6 participants last post by  Wash 
#1 ·
Hello again. :)

So my car has been stood for a while (a month or two?) and when I turned the car on, I noticed that it was low on fuel and the fuel warning light was on, so I filled the car up with about £7 worth of fuel from a petrol can but the fuel gauge didn't move at all. Didn't really think anything of it, thought 5L of petrol wasn't enough to move the gauge up.

My car had been off the road for a few months as I said before, and a few days ago I taxed/insured it again. First thing I did was take it a petrol station and put some petrol in it (£20's worth). Fuel gauge didn't go up, I thought maybe it takes a while to go up but it's been 2 days and it still hasn't moved.

It's just stuck on completely empty and it's not moving at all.
I've done the instrument cluster test and the guage worked fine. I'm just wondering what it could be now?
If it's of any relevance, the car wouldn't start at one point at first turn of the key, and on another occasion, the car started but dropped in revs and died a sec or two later.

Any ideas? Any help is very appreciated because I don't know when I'm going to run out of fuel?!
 
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#5 ·
Yea take the level sensor out of the tank & work it manually & see if the gauge reacts.
If it doesn't then the next thing is to earth the fuel sensor wire through a test light or small bulb & see if the gauge moves then (don't directly earth it as some gauges don't like that, don't know on these so better safe than sorry).

Btw I don't know on these if you can easily access it under the back seat or whether the tank needs to come out!...........

Maybe the TIS can tell you or someone else here :)
 
#6 · (Edited)
I can't see why it would be a problem earthing the tank sensor if only for a second to get a reaction from the gauge.The only dodgy part would be to make sure there was NO power to the sensor beforehand as sparking terminals that close to the fuel tank is a BIG no no:thumbsup

edit: at the end of the day the the sender is only a rheostat and that's the main culprit most of the time
 
#7 ·
Some cars have gauges where 'full' is not a direct earth, I remember being told that if you directly earth those out you can burn the gauges out! I never fancied testing that out ;).
It probably is the sender unit that's faulty, but just as well test it incase a pin's gone bad on the back of the inst cluster (or a wiring problem).

And yea naturally you don't want any sparks near an open tank!:eek
 
#22 ·
How can I test it? Surely the battery has to be plugged in for the gauge to work?

Anyway, I changed both the units at the back - fuel guage STILL won't work!!
I was hoping that would've fixed it :(
Doh! sorry to hear that! :frown

Yea naturally the battery has to be connected, why would you disconnect it?
Turning off the ignition & remove the keys from the ignition is the most you need to do.
Anyway the idea was, you take the sender out of the tank, connect the plug, turn the ignition on (I'm assuming the pump is a seperate unit at this point!), & move the sender up & down & watch the gauge.

Regarding testing the gauge by earthing the wire, that would of been done with the sender still in the tank, so it isn't open & so no danger from sparks.

Btw the last 10s of your video would of sufficed ;)
Regarding the fuel gauge not hitting max, seeing as the problem is no reading at all rather than under reading I wouldn't worry about that just yet.
But to be sure I'll test mine latter to see what it does, or maybe someone else can sooner? :)

Anway, you've already eliminated the fuses, the senders & the gauge so that only leaves the wiring or the plugs (their terminals), btw it is still possible the cluster could be faulty, for example if 1 of the pins/contacts in the cluster socket is cracked or damaged. The gauge would still work on testing but would not be recieving a signal from the sender, although seeing as your fault occured whilst it was stood around I think that's very unlikely.
I think more likely, as mojo said, you might have wiring damage due to rodents!
What you need to do now (& this can a be a big nightmare job I'm afraid) is to do a continunity test from every wire from each sender to their destinations, you'll need to have a good look at a wiring diagram for this, try here http://www.bmw-planet.com/diagrams/release/en/e46/index.htm
Or you might find the problem just by looking along the length of the senders wiring loom & unplug every connection you come across & check the terminals in both sides of the plug. If it's not rodent damage, sometimes water get's into plugs (external ones of course) & corrodes some terminals.
 
#25 ·
Sorry I haven't been able to reply recently, times have been a bit hectic recently.

Anyway, I tried moving the float thing up and down whilst the battery was connected etc, and the fuel gauge still doesn't move. I'll be taking it to an auto electrician next week and see if they can diagnose the problem.

It just shows up as dots like ... ... ... ... or something IIRC. There's another thing that could be related to this issue too, the average MPG counter is a bit whacky. If I reset the MPG counter whilst I'm on the move, it will show the MPG that I'm doing at that moment which will be something around 30ish, but then as soon as I come to a stop, the average MPG will go down quite a lot for as long as the car isn't moving. I filled up with around £20 of fuel and I managed to get about 130 miles from it (town driving), which meant I did averaged 31 MPG. The OBC was showing that I averaged 17 MPG.
Could it be that my instrument cluster is just broken and needs replacing?
 
#21 ·
fuel gauge

I have the exact same issue. Both sensors rh lh are new. Cluster test shows good. Voltage to black wire on both sides are 4.9v. The other is neither ground nor power. Now checked fuses 10 34 and 43. All good. Not sure what else. Issue was it was working right after fuel pump replacement. 1 week later gauge stopped working. Cluster fuel gauge test shows 00.
 
#23 ·
I'm having the same problem on my 2002 330. Just been for a diagnostic and it came back with no faults so thats good. Would a faulty sender unit show on a diagnostic test?

Got a feeling I need to replace one of the sender units but after reading this thread i'm not so sure now!
 
#26 ·
Have you done the instrument cluster test to see if all gauges work?

Everything lights up and all gauges go to max then back down to where they sit when the ignition is off.

Its done through the hidden codes menu on the OBC.

Think it tells you how in the hints and tips guide stickied at the top of this forum.

From what I've found out so far it's worth checking your fuel filter first of all.

Also try post the readings you get from sub menu 6 in the hidden codes.
You need the data from 6.0,6.1 and 6.2.
This will tell you the levels of each and both fuel tanks and also will tell you if you have a faulty level sender.
 
#28 ·
Also check fuses 10/34/43.

If these are all ok it should of at least re-set your cluster to get things corrected again.

It will wipe your clock settings etc but if this doesn't work it perhaps would mean a faulty cluster.

Doing this on mine will make the fuel gauge read correctly.....untill I fill her up again then it won't budge!
 
#30 ·
I thought I would update this for anyone else who's having similar issues - turns out it was the cluster! I took it to a friendly guy called Blair (yes, the one with the 5.7l V8 E46) at Dynotorque (big thanks to him!!) and he diagnosed the fault as the cluster.

Replaced the cluster and fuel guage works, I can finally see when I'm going to run out of fuel now! :D
 
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