# Fuel Sender Unit Faulty 00771 [FIXED]



## katak (Jan 26, 2010)

Hello,

A new issue for me, I imagine that getting 17 years old is the usual age of problems !

I got a 00771 - Fuel Level Sensor (G): Open / Short Circuit to B+

=> VCDS is showing 330 Ohms and I've never seen this value anywhere on a forum... my TT 225 is post May 2002:
From 05/02
Sensor 1
Lower 147 Ohm
Upper 29 Ohm
Sensor 2
Lower 140 Ohm
Upper 27Ohm 
(Thanks Hoggy)

I'm going to unmount the fuel pump on left and right to check values but before I need you:

1. How can I get open or short circuit if resistance measured is 330 Ohms ?
2. For this schematic, where to plug the DMM on each unit ?










Cheers Everyone


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## Hoggy (May 8, 2002)

Hi, I assume your TT is not Quattro & only 1 float assembly

Connections for FWD & Quattro
1 pump supply 12 v plus
2 Fuel sender 12 v neg 
3 sender to fuel gauge
4 Fuel pump 12 v neg

2 & 3 to measure resistance.

Hoggy.


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## katak (Jan 26, 2010)

Hi Hoggy,

Yes this is a quattro, I assume TT225 does not exist without this nice feature ?

I'll test the pin 2 & 3 tomorrow, thanks a lot.


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## Hoggy (May 8, 2002)

Hi, Quattro has 2 level senders & resistances are different.
From 05/02
Sensor 1
Lower 147 Ohm
Upper 29 Ohm
Sensor 2
Lower 140 Ohm
Upper 27Ohm


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## katak (Jan 26, 2010)

Thank you Hoggy !


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## katak (Jan 26, 2010)

I finally fixed the sender... I don't know for how long !

I removed the metal plate and replaced by a spring I soldered:










Then I polished badly the resistance slider and soledered the wires:










Now all is accurate so far...
Cheers


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