mrdork

Over 4700 miles on my C6 without any real trouble. However, after filling my tank this evening, I received the "Check Engine" light along with the message "Service Fuel System" on the DIC. "Ok, I guess I didn't properly tighten the gas cap..." so I checked - it was tight. I removed it and re-tightened. Same error message. During the short 8 mile drive home, the DIC alternated between "Service Fuel System" and proper operation and the fuel gauge alternated between full and empty (in sync with the DIC.) Once home I shut down, inspected the gas cap & filler neck but could find nothing wrong.

Since I haven't purchased a scan tool yet I can't check the error code tonight. I guess I'll have to take it to the dealer in the morning

Has anyone else experienced this behavior?

JJayzX

Do you think the sensor that tells if gas cap on or off could be faulty.

AveryOBX

Did you leave the engine running while you were filling up? Yea I know, stupid question but this is the most common cause.

Braced

If your car is equiped with OnStar, they can tell you the code and meaning of it. It's one of the selling points of OnStar for me.

need1

not quite the same problem but my check engine light came on and the cap was tight.....turned out to be the oxegon sensor - dealer replaced it and all is fine.

mrdork

AveryOBX - No, C6 was off during fueling.
Braced - No OnStar.
need1 - Interesting.

We'll see what the dealer has to say later today...

Thanks for the input!

carpe dm

Did you over-fill and get some gas in the return pipe? That would do it.

DP Dave

800 miles and my DIC read "Service Fuel System", fuel gauge went to empty. Turned out it was the Fuel Gauge Sending Unit.

digbyamb

This is well documented within the forum. I had this exact same thing happen at 250mi and it was a FSU. The dealer needs to replace it, make sure his has one in stock BEFORE he removes the tank or you will be sitting without your car for up to a week.

Dash Culpepper

I have the same problem. My dealer had to order a left sending unit. I am still waiting for it to come in. Including yours and mine that makes at least four C6's that have had the same problem. This was a problem that was not uncommon in the C5

mrdork

Went to the dealer this morning but their service dept. was closed. So, I continued with my day running errands. After about 35 miles and the fourth start, the check engine light no longer illuminated and has not returned.

Yes, it is possible that I overfilled the tank since I always give the pump an extra shot to make sure it's really full (not a crappy pump shutting off early.)

I'll go to my regular dealer (near my office) on Monday and have them check to codes to find out what really happend.

Thanks to everyone for your quick suggestions and pointers!

Best regards,
-Mark-

LS WON

I find that I can usually get one more gallon in after the click.

champ_85

Mine happened at 1300 miles. I took my car back to the dealer and didn't see if for a week Wish I had seen your warning earlier!

digbyamb

I think you will find that as soon as you fill your car the problem will be back until you burn some of the gas off (I found that if the tank was 1/2 full or less the problem disappeared).

Don't let the dealer remove the tank without having the FSU in stock. He can check it using the codes without tank removal. I waited 7 days with the tank sitting on the floor of the shop waiting for a FSU to arrive.

Dash Culpepper

Yep, I am still waiting for the part to come in, it has been two weeks now. I called GM this morning trying to see what I could do to get this matter moving and really did not get any where. My '03 was bought back by GM under the Lemon Law, I sure hope this is not going to turn out the same way again. I did not think lightning could strike twice.

billdog

Was this covered under warranty? I have the same problem, but my 3 year 36K warranty expired in November 2010. I think it might be covered because the check engine light is on.

soemer

My problem is just the opposite. My check engine light comes on just about the time I reach the 1/2 full point and below. It goes out after a few miles after I fill up. The code says evap. emmisions.

This never happened until I had the fuel level sending unit(s) replaced. I have a 2000 Corvette, and they had a problem with the gas guage reading empty as soon as it hit 1/2 tank. ABout six months after the sending units were replaced, the problem began, and I have now had it for years.

I'm guessing an air leak somewhere, but I have no idea where to start looking. Any thoughts?

Knob Jockey

You guys should consider starting a new thread, this one is ancient.

Sorry for your problems, nonetheless.

MikeyTX

Existing threads receiving no replies for 45 days or more.
If an existing thread has not received a reply for a period of 45 days or more, members should create a new thread which is identical or similar in nature, rather than to post to the existing one.

johnodrake

Indeed