Ye olde way of telling if it was sender or gauge ,was to take wire off sender, and see if display showed empty. Full earth on sender wire and should show full. Fail that and sender was faulty. Without a wiring diagram, ( and Haynes has gone walkies at moment) I'd hesitate to suggest if that would work, but it should be possible to test the sender unit using a meter. Then if sender tests OK, use sender to test gauge.

 

hmm ive said both work :P

Negative, the sender sends a resistance measurement to the instrument cluster ECU, the ECU then interprets this algorithmically and tells the gauge what to read, I believe the ECU can be adapted by changing the numerical value used in the algorithm, the procedure is to empty the tank then put exactly 6 litres of fuel in and substitute adaptation values until the gauge shows empty (bottom of the red zone).

they both work ... ive already said this in previous posts... you cant check any better than ignition on pull out the unit move the arm, and watch the gauge move

 

issue is not "its not working" issue is now, why the fck it wont fit and work lol

Maybe you have 1.2 petrol tank in your 1.9 deisel.

Maybe you have 1.2 petrol tank in your 1.9 deisel.

you know what mate, after spending a fair bit of money and  2 weeks worth of time mopping up previous owners cockup, it wouldn't surprise me in the least!!

Yep, I don't know where you bought this Fabia, but well done to you for having such patients!

Stick with it, you'll get there.

plan with 

 

Yep, I don't know where you bought this Fabia, but well done to you for having such patients!

Stick with it, you'll get there.

 

plan with this issue is to run to as near empty as i can, then drain it, i guess i can just disconnect before the fuel filter then turn on / off ignition lots to pump it out?

Yep that's fine, it will pump all the fuel out the tank.

Get two drums ready.

Instead of cycling ignition to prime pump you could just jumper the relay to make it run constantly until empty

Ok its now got £3 worth of diesel in. It did have £5 but will have used £2 after running out on the motorway, and the misses had to bring me some lol

 

Tomorrow i will get this dam tank sorted !!

hmm so its reading the opposite when empty it shows full :P

Maybe the sender unit has been fitted to the pump assembly upside down somehow? That might explain why you're having trouble getting the thing into the tank too, if the float arm isn't pointing the right way?

How does it look compared with the image on this page?

been following this with some interest- if it reads reverse and someone has been messing maybe 3&4 have been reversed ,those small connectors only look like they work once then no guarrantees  ---I suspect my problem lies with 3&4 as I changed the sender unit and it's erratic now---the "printed circuit" r'stat appears to be printed onto glass/ceramic and is VERY brittle   if it's not damaged pro'bly best left  I'm going  to try solder paste when the weather is warmer 

Maybe the sender unit has been fitted to the pump assembly upside down somehow? That might explain why you're having trouble getting the thing into the tank too, if the float arm isn't pointing the right way?

How does it look compared with the image on this page?

 

 

been following this with some interest- if it reads reverse and someone has been messing maybe 3&4 have been reversed ,those small connectors only look like they work once then no guarrantees  ---I suspect my problem lies with 3&4 as I changed the sender unit and it's erratic now---the "printed circuit" r'stat appears to be printed onto glass/ceramic and is VERY brittle   if it's not damaged pro'bly best left  I'm going  to try solder paste when the weather is warmer 

 

Update, I have 2 units they work fine im sure... i have tested all the wiring and i think its the ground thats the issue, google says if the ground is faulty the unit will recieve either higher or lower amps, making it work backwards.. apparently its a very common issue on all makes and models..

 

Anyone have any idea where the ground point is???? 

Seems like you're looking to check the brown/white wire from pin 2 of the 4-way connector at the fuel pump, to some vague 'sender earth connection' in the wiring loom behind the dash panel:

 

That's for a 2004 ASZ engine car, dunno if they vary at all between engine codes and years, but probably not.

Seems like you're looking to check the brown/white wire from pin 2 of the 4-way connector at the fuel pump, to some vague 'sender earth connection' in the wiring loom behind the dash panel:

 

That's for a 2004 ASZ engine car, dunno if they vary at all between engine codes and years, but probably not.

 

Oh ...

 

I thought the big brown wire either pin 1 or 4, connects to a chassis earth ... like the point left side of the boot?

That sounds like the pump motor earth, 1.5mm² brown wire from pin 4 to some other, equally vague, 'earth connection in wiring loom behind the dash panel'.

 

Doubt that one is relevant to the gauge, but I could be wrong.  I'd imagine they are separate earths so the pump load doesn't affect gauge readings.

 

Have you had any water leaks into the cabin? Especially up under the dash? That sort of thing can cause earths to go high-resistance, if they get all green and corroded.

not recently but possibly previous owner, was all clogged up with leaves and sludge blocking all water routes. And it had a few blown fuses when i bought it. btw do you know if the sender has a individual fuse, or is it run off the relay?

Sender is wired with that lilac/black thin wire from pin 3 of the 4-way, straight to pin 15 of a connector 'T32a' that goes into the dash panel/clocks unit.

 

Dunno which fuses cover the clocks, but there's a handy-dandy pinned thread in the technical guides section that may help, thanks to Lee01.  I doubt there's a specific fuse just for the gauge wiring though. Check through the list.

cheers for that, checked list and just the one fuse for instrument cluster so no, looks like im going to have to take the dash panel off, not that i have a clue what to look for, other than the same colour wire, corrosion, loose wire.

Edited 11 April, 201511 yr by FromTheDarkness

There are a few earth studs on the floor of the cabin, just in front of the gear stick, which you can get to by removing the centre console (plastic bit around handbrake lever and gearstick).  They're not that easy to see, I seem to remember, cos carpet and sound insulation  and other bits cover them, and I have no idea whether the wiring you're interested in goes anywhere near this area.  Does the wiring from the 4-way at the fuel pump seem to head off down the side of the car, or down the middle? Just gotta follow it round the car mate, really.

Seems to go down the right side( drivers)

 

I dont know if anything is related, but seem to have a few other electrical issues after a scan ( im rubbish with vcd btw:P)

 

VCDS-Lite Version: Release 1.2

Saturday, 11 April 2015, 16:37:31.

Control Module Part Number: 6Q1 937 049 C

  Component and/or Version: 00 BN-SG.           1S33

           Software Coding: 25738

            Work Shop Code: WSC 13765

                      VCID: 3B09B4EF3A7D

4 Faults Found:

01598 -  Drive Battery Voltage

        27-00 -  Implausible Signal

00511 - Shareware Version. To Decode all DTCs

        49-00 - Please Register/Activate

00778 - Shareware Version. To Decode all DTCs

        49-00 - Please Register/Activate

01324 -  Control Module for All Wheel Drive (J492)

        49-00 -  No Communications

 

 

VCDS-Lite Version: Release 1.2

Saturday, 11 April 2015, 16:39:35.

Control Module Part Number: 6N0 909 901 

  Component and/or Version: 31 GATEWAY  CAN    1S33

           Software Coding: 00014

            Work Shop Code: WSC 13765

                      VCID: F093D3C3A3BB

3 Faults Found:

00511 -  Selector Lever (E313)

        49-00 -  No Communications

00778 - Shareware Version. To Decode all DTCs

        49-00 - Please Register/Activate

01324 - Shareware Version. To Decode all DTCs

        49-00 - Please Register/Activate

 

 

VCDS-Lite Version: Release 1.2

Saturday, 11 April 2015, 16:42:20.

Control Module Part Number: 6Y0 820 045 

  Component and/or Version: Klimaanlage        X0830

           Software Coding: 

            Work Shop Code: 

                      VCID: F297D9CBADB7

10 Faults Found:

65535 -  Internal Control Module Memory Error

        00-00 -   -

01271 - Shareware Version. To Decode all DTCs

        30-10 - Please Register/Activate - Intermittent

01596 - Shareware Version. To Decode all DTCs

        30-00 - Please Register/Activate

01596 -  Motor for Outside/Recirculated Air Flap (V154)

        29-10 -  Short to Ground - Intermittent

01271 - Shareware Version. To Decode all DTCs

        41-00 - Please Register/Activate

01271 - Shareware Version. To Decode all DTCs

        29-10 - Please Register/Activate - Intermittent

01596 -  Motor for Outside/Recirculated Air Flap (V154)

        41-10 -  Blocked or No Voltage - Intermittent

01596 - Shareware Version. To Decode all DTCs

        29-10 - Please Register/Activate - Intermittent

01596 - Shareware Version. To Decode all DTCs

        28-10 - Please Register/Activate - Intermittent

00706 -  Relay for Coolant Fan; Stage 2 (J513)

        31-00 -  Open or Short to Ground

Here you are:

 

http://wiki.ross-tech.com/wiki/index.php/Category:Fault_Codes

 

Get cracking.

Ive googled a few and most are pointing to earth issues in the ECU, hmm ... the sender is controlled via the ECU so if earth point here is bad, it may not be the dash panel .. is this possible?

Ive googled a few and most are pointing to earth issues in the ECU, hmm ... the sender is controlled via the ECU so if earth point here is bad, it may not be the dash panel .. is this possible?

 

Bear in mind the car has many ECU's, which is why we've started to refer to the engine ECU as the PCM. The PCM will not be what controls the fuel gauge, that will be the instrument cluster ECU as wino indicated.