Tank System Failure

[PeteG]

Hi guys. I'm having a real problem with my 2014 S3 that I just can't seem to get sorted. About 6 weeks ago it came up with tanks system failure error message and the accompanying red flashing fuel empty warning light on the fuel gauge. I know nothing about cars so looked it up online and it didn't look a big deal, probably just needed a new sender. Booked it into a local and really well respected Audi specialist who found that the sender hadn't just failed but had literally burnt out. He actually said he hadn't seen that happen before and that it was a bit worrying that it had burnt out in the fuel tank! They replaced the sender but the error didn't go. So they decided it must be the other fuel tank sender (this is where my lack of knowledge is a problem, is it a second sender in the fuel tank or at least something very similar?). Anyway after it taking best part of a month to get hold of that second part because there was a problem sourcing it, they replaced it yesterday. They assumed that would sort the issue but it hasn't. They seem completely stumped and said they can't believe replacing the two parts hasn't solved the problem. They say they have checked the wiring and it is all showing as being fine but it is still showing "high resistance". None of this means much to me but as I said, they are pretty well thought of as a garage and they don;t seem to know where to go with it next. I'm worried not just because it really bothers me that my car isn't right and I don't know how to get it fixed but also because if the first sender burnt out and there is still this "high resistance" them I'm concerned my car is potentially a fire risk? Any help/ideas would be massively appreciated because I'm really getting to the end of my tether. The car is my pride and joy and it's getting me down.

 

[ViperG]

I would think that it's still an issue with one of the two senders or they did something wrong. They should be able to test them to see which isn't working correctly. Do you trust the shop? because this seems like an easy fix and will only affect your fuel gauge on the dash so you could continue to drive around as long as you monitor the gas level with your mileage. I wouldn't worry to much about a fire hazard a lot of cars have internal tank fuel pumps. That freaked me out working on them or just thinking about an electric motor sitting in fuel with exposed wires.

 

[PeteG]

I would think that it's still an issue with one of the two senders or they did something wrong. They should be able to test them to see which isn't working correctly. Do you trust the shop? because this seems like an easy fix and will only affect your fuel gauge on the dash so you could continue to drive around as long as you monitor the gas level with your mileage. I wouldn't worry to much about a fire hazard a lot of cars have internal tank fuel pumps. That freaked me out working on them or just thinking about an electric motor sitting in fuel with exposed wires.

Cheers. The garage has a pretty good reputation, I started using them because a few people mentioned them on various Audi forums saying they were decent. Both senders have been replaced so if one of the new senders is not working, would that indicate another issue that is causing them to fail/burn out? He did say that he hadn't seen a sender in that state before, properly burnt out.

 

[ViperG]

Odd though the sender is usually just a potentiometer that varies resistance based on the level of fuel. You would think that a short/issue further up in the wiring would cause the fuse to blow not the sender to burn out. I would think a short in the actual sender would be the only way for it to "burn out" Should be easy to test the sending unit to see if the resistance changes based on the level of the float. All just guesses though I've never tested one myself.

 

[PeteG]

Odd though the sender is usually just a potentiometer that varies resistance based on the level of fuel. You would think that a short/issue further up in the wiring would cause the fuse to blow not the sender to burn out. I would think a short in the actual sender would be the only way for it to "burn out" Should be easy to test the sending unit to see if the resistance changes based on the level of the float. All just guesses though I've never tested one myself.

Had it all checked by an auto electrician. Wiring all fine but says he's 95% certain it needs a new instrument panel. Bit if a blow to say the least. God knows how much this is going to set me back.

 

[ViperG]

Thats not fun. I had mine go in my TT. Looks like the part is $1500.

 

[PeteG]

Thats not fun. I had mine go in my TT. Looks like the part is $1500.

Is this not an uncommon thing to happen then? Surely you should reasonably be able to expect an instrument panel to last the lifetime of a car? I mean my car is 6 years old, seems awful that such an integral and expensive part should go after 6 years.

 

[ViperG]

Well the TT version. I had was still pretty much a concept car. I don't see it being a wide spread issue.