Tank system malfunction?

[Jhearty99]

Just got in my car and got a Tank System Malfunction. Contact Workshop error? Any idea? Fuel level is now on empty.

[d1amund]

Defective sending unit

[Jhearty99]

Of course. Literally days after my warranty expired

[Jhearty99]

Audi currently doing extensive diagnostic. Told me at least 5 hour diagnostic. Pulling instrument panel, going through fuel components, etc. Audi of America is in contact with the dealer regarding the matter. Hopefully they will step in for at least a portion.

[Not A Good Idea]

Audi currently doing extensive diagnostic. Told me at least 5 hour diagnostic. Pulling instrument panel, going through fuel components, etc. Audi of America is in contact with the dealer regarding the matter. Hopefully they will step in for at least a portion.

happened to me as well. new sender unit.

[Jhearty99]

I mentioned that to them. I would hope they checked that before pulling the instrument panel and such. Doesnt seem like a sending unit would require a 5 hour diagnostic.

[ExhaustNote]

They'll probably cover it under warranty if you were literally just days over.

[Jhearty99]

11 days out. Happened on Saturday so would have been 9 but they weren't open to bring it in.

[d1amund]

All that malarkey and they could just pull out the rear seat and change out the sending unit. Someone is looking to pad the bill to AoA lol

[Jhearty99]

Finally got the car back today. AOA covered the parts but not the labor. Ran me just under $1000. Fun times

[d1amund]

1000 in labor for what?

[Jhearty99]

Came to 973 after tax


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[JamesRS5]

Ah, they permomed the wiggle test, that must be worth at least $500 on its own.

[JK01.4.2A6]

This just happened to me today. 2010 S5 coupe 4.2. I suspect it's the sender on mine as well, but aren't there two senders (front and back)? If so, which one, and are they both accessible under the seat?

Complete symptom description- no problem when I stopped the car when I got to work and parked. There was probably 60 miles to empty showing on the dash, and fuel level was around a quarter tank give or take. When I got out from work and started her up, she showed 0 miles to empty and the gauge was below zero- the needle was pinned at the bottom. Stopped and topped it off, but no change on the readouts. Drove maybe 20 miles, and somewhere along the way the gauge popped up to 3/4 tank, and the miles to empty was about 250. Thought maybe the sender float was sticking, and maybe I didn't really top it off, so I stopped and topped it off again, being careful to really top it off. It took about a gallon and a half, but the gauge didn't move above 3/4 and the miles to empty stayed at 250. As I drove home, another 20 miles, the gauge needle came down slightly, and the miles to empty was showing 245 or so, so they seemed to be going down as I drive, but they didn't start at full tank or my usual 355 miles to empty on the full tank.

Thanks!
Jim

Update- 6 October 2016

Tank malfunction comes on at start, with 0 miles to empty and gauge showing empty. After about 20 minutes of driving, gauge comes up to what looks to be the actual gas level, and miles to empty displays accordingly. As I drive, gauge and miles both go down. BTW, it's a 2010, but it only has 28000 miles on it.

Question- I guess there are two level senders. So which one transmits to the gauge/miles to empty readouts in the cluster???

Thanks,
Jim

[Mindriddle]

This just happened to me today. 2010 S5 coupe 4.2. I suspect it's the sender on mine as well, but aren't there two senders (front and back)? If so, which one, and are they both accessible under the seat?

Complete symptom description- no problem when I stopped the car when I got to work and parked. There was probably 60 miles to empty showing on the dash, and fuel level was around a quarter tank give or take. When I got out from work and started her up, she showed 0 miles to empty and the gauge was below zero- the needle was pinned at the bottom. Stopped and topped it off, but no change on the readouts. Drove maybe 20 miles, and somewhere along the way the gauge popped up to 3/4 tank, and the miles to empty was about 250. Thought maybe the sender float was sticking, and maybe I didn't really top it off, so I stopped and topped it off again, being careful to really top it off. It took about a gallon and a half, but the gauge didn't move above 3/4 and the miles to empty stayed at 250. As I drove home, another 20 miles, the gauge needle came down slightly, and the miles to empty was showing 245 or so, so they seemed to be going down as I drive, but they didn't start at full tank or my usual 355 miles to empty on the full tank.

Thanks!
Jim

Update- 6 October 2016

Tank malfunction comes on at start, with 0 miles to empty and gauge showing empty. After about 20 minutes of driving, gauge comes up to what looks to be the actual gas level, and miles to empty displays accordingly. As I drive, gauge and miles both go down. BTW, it's a 2010, but it only has 28000 miles on it.

Question- I guess there are two level senders. So which one transmits to the gauge/miles to empty readouts in the cluster???

Thanks,
Jim

I’m new to the site and having this same issue. Has anyone determined which sending unit goes bad for this issue? One in the trunk or the one under the rear seat?

[Funt]

I’m new to the site and having this same issue. Has anyone determined which sending unit goes bad for this issue? One in the trunk or the one under the rear seat?

I had similar problem last year.
You can see the delivery unit in the picture below which is located under rear seat.
Both senders connect to the pos. 13.
The first sender mounted to the delivery unit pos. 1.
I had wire break of the second sender.
The wire of the second sender lies through the tank to the sender.

I restored the wire of the second sender and I got information about fuel in the tank, but this information was incorrect.
The computer started to correct it after about 5 refuels and I got real information after 8 - 9 refuels.
The sender is just potentiometer which has own resistance and you have to test it.






To obtain an exact measurement of the resistance value for the specification “Tank full”, the fuel tank must be completely full. For this, drive for at least 500 metres after filling the tank to let air bubbles escape from the fuel tank; then add fuel again.

– Connect multimeter (resistance test) between contacts -2- and -4-.
l Tank empty: approx. 280 Ω.
l Tank full: approx. 65 Ω.
– Connect multimeter (resistance test) between contacts -2- and -6-.
l Tank empty: approx. 60 Ω.
l Tank full: approx. 275 Ω.
– Connect multimeter (resistance test) between contacts -4- and -6-.
l Sender in any position: approx. 340 Ω.

In order to test the maximum and minimum resistance values for “tank full” and “tank empty”, remove the fuel gauge sender -G- → Chapter and move the float all the way to its top or bottom position.
t The following values are obtained with the fuel gauge sender removed, due to the greater travel of the float arm:
– Connect multimeter (resistance test) between contacts -2- and -4-.
l Sender at lower stop: approx. 288 Ω.
l Sender at upper stop: approx. 57 Ω.
– Connect multimeter (resistance test) between contacts -2- and -6-.
l Sender at lower stop: approx. 52 Ω.
l Sender at upper stop: approx. 283 Ω.
– Connect multimeter (resistance test) between contacts -4- and -6-.
l Sender in any position: approx. 340 Ω.
Fuel gauge sender -G- is defective in the following cases:
t Large differences in test readings
t Reading: 0 Ω (short circuit)
t Reading ∞ Ω (open circuit)


Connect multimeter (resistance test) between contacts -2- and -3-.
l Sender at lower stop: approx. 290 Ω.
l Sender at upper stop: approx. 16 Ω.
– Connect multimeter (resistance test) between contacts -1- and -3-.
l Sender at lower stop: approx. 50 Ω.
l Sender at upper stop: approx. 324 Ω.
– Connect multimeter (resistance test) between contacts -1- and -2-.
l Sender in any position: approx. 340 Ω.

[eskimo0101]

Ah, they permomed the wiggle test, that must be worth at least $500 on its own.

I know this is an old quote but I'm glad I'm not the only one who spotted "performed wiggle test" on the official diagnostic report.