Timz06

Hi Guys,

I have an 08 z06, my fuel gauge went to zero the other day. I have since ran a couple of tanks through. But is still at zero, get the message service fuel system. I'm planning to take this in to get fixed, but I would like to know the cause before I take it in. Is this a common problem, and what is the root cause? I would hate to see them pull the fuel tank on my new car to fix the sending unit.

Tim

0Jason.ServiceSpecialist

This used to be a problem on the 2005s and some 2006s. I have never heard of this happening on a 2008. It may be that the computer just needs to be reset.

ZL-1

As Tim said, C5's and early C6's had a lot of fuel sender problems and many revisions. Haven't heard of any recent problems. It would be worth it to first check and make sure a connector didn't come off either of the tank sending units. The gauge defaults to empty when any reading is out of range. If everything looks ok it will be necessary to scan the codes and see where it leads.

1HOT427

I had this happen on my '07 Z, build date Oct. 3/06. Dealer replaced sender. No problems since.

Timz06

Well I scanned the codes and found this

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P2066 Fuel Level Sensor 2 Performance

CONDITIONS FOR RUNNING THE DTC
The ignition is ON.

CONDITIONS FOR SETTING THE DTC
The ECM does not detect a change in the secondary (left) fuel level of at least 3 L (0.79 gal) over a distance of 320 km (200 mi) .

ACTION TAKEN WHEN THE DTC SETS


The fuel gage defaults to empty.
The driver information center (DIC) illuminates the FUEL LEVEL LOW message.
The ECM records the operating conditions at the time that the diagnostic test fails. The ECM displays the failure information in the Failure Records on the scan tool.
CONDITIONS FOR CLEARING THE DTC


The DTC becomes history when the conditions for setting the DTC are no longer present.
The history DTC clears after 40 malfunction free warm-up cycles.
The ECM receives the clear code command from the scan tool.

I reset the code and the fuel gauge is back. I'll see if it sets again, it could be there is a problem with my left sending unit. I'll take a look to see that all the connectors are there.

Thanks for the replies,
Tim

quickc6

Had it happen a 05 z51 . Had to remove the trans. , dif. and
fueltanks to repare the sending unit .

1HOT427

I think I was confused...
They didn't replace the sender, I believe they said they reflashed the computer. I think at that time I was also having 'Service Active Handling', 'Service ABS Brake System' and 'Service Fuel System' warnings on the DIC. All went away after service.

Timz06

So now understanding the situation, that is there are two sending unit, the computer compares both, and shuts down the gauge if they are not measuring the same amount of fuel.

Since some have said the dealer cured this with a "reflash" I would bet that this software change is turning off the bad sending unit, in lieu of replacing it, which sounds like a costly endeavor.

Tim

jschindler

I know this is an oldie, but I had this happen to mine this morning and found a few instances of it happening on 08s (yes, I did the search before posting a new thread - do I get a gold star? ).

I have half a mind to use this as an excuse to buy a scan tool, but on the other hand, I'm due to go see my dealer anyway (They have gotten to be pretty good friends right up to the owner).

Just wanted to bring this thread back and see if there is any follow up from anyone who has had this problem.

P.S. - I just realized this was in the Z06 section - Hopefully I'll get some hits here. If not, I may start a new thread in the General C6 section.

Thanks

yolo300

I had this problem with my fuel gauge- I disconnected the battery and the problem solved itself

slolane

This was a pretty common problem on the c5s the cure was to run a bottle of techtron thru the tank. Sulphur would build up on the sending unit and make it read empty. The techtron would clean it off and it would be fine. I am not sure if its the same problem but its worth a try for a lot less money than taking it in. I hope this helps

Red C6 Z06

OK, I had this happen yesterday afternoon. The Fuel level display dropped to empty and I got the "Service Fuel System" message along with the "Low Fuel" message.

I haven't put the scanner on it yet, but plan to do so this morning. In the meantime friends of mine told me about the Techron thing. I knew about it from the C5 but never had it happen on the C5 (always full of gas). I figured that GM had fixed that problem in the C6. I had let the tank drop to about 1/4 a couple of times just this past month, so I am suspecting that it *IS* the sensor corrosion issue.

I really don't want any GM mechanics (or any mechanics) touching my car unless absolutely necessary, so I'll try the Techron thing and see if it helps.

Does anyone have any idea how long it takes the Techron fix to work?

90sundevil

Fuel sending units, was a big problem in 05 when the C6 came out.

Beast5spdGTA

$5 fix, worked for me in less than 30 miles. You got to love the internet and forums. I'd try that first, and second, before letting the dealership molest your car and waste hours of your time, that could be a simple fix.

I have an '07 Z06 happened around 55K miles. Hasn't re-occured in 10+K miles (I think I put an additional bottle or two though it since that time just b/c).

turbo50mike

I have the same issue with my 2007 C6 Z06...Recently the gauge will drop to zero, I'll get the 'fuel level low' and 'service fuel system' message as well as a check engine light.

I scan the codes, and got the same thing as TimZ06 (post #5). Fuel level sensor 2 out of range or something like that. Clear them out, but it returns after a few miles...

If I drive it a bit, it will work properly...Then 10 miles later it's 'empty' again...Then it works, etc, etc....

I'll try the Techron appliction and see if that helps.

Undy

...same problem with my 07. There's a GM TSB on the subject. Run one or two 20oz bottles of Techron's fuel system cleaner (not fuel injector cleaner) Use one bottle and run that tank through. Disconnect the battery and wait 30 minutes to reconnect. If that doesn't do it run one more bottle, same scenario. It worked for me and I have no more issues. I was told that the detergent levels are down on a lot of fuels and the sulfur in the fuel is plating out on the fuel sensors.

If this doesn't work you're facing a $1.5K repair if you're out of warranty.

BADZ

Mine has been doing the same thing. Bought some techron and will see what happens..

BADZ

Techron did not work, I fill the tank all the way up, run the car and when it reaches 1/2 tank then it drops to Empty and that "service fuel system" notice comes on my DIC.

I guess there nothing to do but drop the tanks...

Undy

Techron finally stopped working for me too.

My dealer appealed to GM for me and they picked up 50% of the tab. It cost me around $300 as only one tank needed to be dropped. I was waaaay out of warranty too.

jimman

This is a result of current regulations with Lead use, ROHS. Silver is used in PC board pass through connections and reacts with Sulfur in the gas, cheaper gas more Sulfur and Silver sulfate. Techron is the first step but only a bandaid. These are photos of what I had to do with my 2000 which is the same as those used today. Incidentally I have the same problem now but I told dealer I'll use a frikken stick before I dump 1200 for a gass guage.