Rogers 07

I'm getting a P2068 code and and the fuel gauge stops working when I fill up my car. (07 A6 Z51). Does anyone know which fuel tank the gauge sending unit is in? I see pumps for the passenger side tank that do and do not have a sending unit on them and delco makes a sending unit for both tanks, any help would be appreciated.
Thanks

CO Lightfoot

The C6 system is similar to the 2004 C5, described in this pdf file: http://www.hessh.de/Corvette/FuelTankSystem.pdf

Operation of Fuel Level Gauge
... Each fuel tank has its own [fuel level] sensor... The PCM supplies a reference of 5 volts to the two sensors. Each sensor operates across a range from full (2.5 volts) to empty (0.7 volts). The PCM monitors the fuel level sensor voltages and calculates how much fuel is in the two tanks. The readout of the fuel gauge is a result of this calculation.

Maybe someone with real experience will chime in. But to me, replacing the sensors doesn't look like a DIY job. Certainly it's beyond my ability.

And it might be a problem with the PCM, not the sensors.

Anyway, that's all I know. Hope it helps.

foremaw

If you haven't I would run some Techron through it for a couple of tanks to see if it being caused by deposits on the sensor. Some folks have had some luck clearing them up.

Ketchum

I'd run some Marvel Mystery OIL in it lot quicker then I would a bottle of Techron. It dissolves deposits quickly and is a great lubricant. I used it a lot in diesels to free up tank senders.

ChevyDave

You probably arent going to attempt tank removal yourself, but still, i found this vid quite interesting.. P2068 pump fix
http://vehiclefixer.com/videos/how-t...te-code-p2068/

OnPoint

Otherwise I think the tanks have to come out. And that's not a job for the meek of heart.

Rogers 07

Thanks guys. I Appreciate the advice, evey bit of info helps !!

Rogers 07

That video was great, Taking the tank out would have been difficult if not impossible with out it. The sending unit in question was indeed covered with what ever it is that builds up on the contacts. I replaced the entire pump and sending unit assembly while I had it out. FYI, the Vette has 91,826 miles on it, so looking at it like that, assuming an average of 22.5 MPG (Which is what my car averages !!) The tanks have seen about 4080 gallons of fuel go thru them !!. Still it sucks that a sending unit would last about 5 years or so and cause that kind of a problem !!! Anyway, Thanks again. Roger.

ChevyDave

OMG... are you saying you viewed the vid, went and found/bought pump parts, dropped the tank, installed them, reinstalled tank and typed your reply in just over 4 hours? impressed, very impressed.

btw.. you have A6... i heard that its required to drop driveline and some exhaust on them. (maybe thats only for dropping driver side tank)

good job!!!!

Rogers 07

Thanks, it wasen't as scary as you would think, I had the spare pump and sender ready to go, so it only took about 2 hours to take it apart, check it out replace the pump and renstall it, Also having access to a shop and a friend to help me do it, really cut down on the time. !!

foremaw

You're right that was a fantastic video on this. Great job on the DIY, I probably would not have tackled it. To stave off the evap deposits I usually fill up when the tank reaches half to keep the sensors submerged during the times the car is not being driven.

C6topless

I would pay you to fix mine.

Tony1leo

Just changed my sending units per the video. It is doable. I had to do it on the floor with the car jacked up. It was hard getting the crossover pipe disconnected, and it was hell putting it back in along with the evap hose on top of it. But I got it done. It did take me pretty much the entire day with several breaks. My guess for me was about 6 hours total. I do have the pedal shift unit and it was very tight working around the differential. I also had to drop my exhaust, which wasn't that big of a deal, but was not mentioned in the video. I also had to drop the driver side tank because I didn't have enough space to free the crossover pipe without dropping the other side. It's not a complex job as far as automotive repair knowledge goes, but it is very difficult as far as getting to parts in very tight spaces and working in the blind (by touch) when reaching up to reconnect the crossover pipe and evap hose. That was the hardest part to me. It probably accounted for 2 hours of the job and 95% of the frustration. I check 2 dealers and they both wanted $3500 to do the job. 11 hours of labor to drop the differential and replace the sending units. Sending units were about $75 each online, $130 at the dealer. But like stated previously, it is not a job for the seek of heart or impatient people, because it will test your nerves, and you're going to wonder how in the hell are you going to get it back together. Just don't give up...you will eventually get it.

AORoads

good grief! good going to the two of you, one belatedly. helluva good job!

Ketchum

11 hours!

TripleAstyle123

From what I am reading it is doable without a lift!?? How high on jackstands did you lift the Vette to do this? Just wondering for future reference! Thanks!

djdinoe

Man, I've been stuck with this issue on my Vette too. It started to happen around 30k miles. I'm quite ticked off that the sending unit has to be replace at this early stage. I have yet decided on a DIY or take it to my shop.

CO Lightfoot

Have you tried a fuel system cleaner?

Tony1leo

I jacked up the front end about 15 inches and the back about 20 inches off the ground measuring from the bottom of the door still. You need this minimum clearance to drop the tanks straight down. One other thing you will want to do is mark the alignment of the crossover tube on each end before you disconnect it, because you will be guessing where to slot it back in otherwise.

Tony1leo

Watch the video. It's fairly accurate on getting it apart. He just fails to state how much more difficult it is to get it back together. Maybe it's not so bad with the manual, because they say the manual takes up less space than the automatic.