Forum Discussion

burlmart's avatar
burlmart
Explorer
Feb 10, 2015

CEL After Failed COSTCO fill + OBD II Scan

In the past, the CEL came on maybe twice, and we fooled w/ gas cap and within a day, light went off. Looks like it wants to stay on
tho not blinking. It came on after COSTCO pumps were under too much pressure or something, and gas would not go in the 3/4 empty tank. We went to a Shell station and it looked like we were gonna have same issue (pump stops almost as soon as you pull trigger to start), but it started pumping and filled tank. Noticed CEL on next trip. Have filled it normally once since, but lite stays on. Running smooth, otherwise.


1) Are there any unique notices a 6.0L "05 Chevy would give at 42.5k mi?

2) After gas caps, what is a common cause of CEL?

3) If Autozone lot looks too small or they no longer scan vehicles, which of these scanners would you recommend:

http://www.autozone.com/test-scan-and-specialty-tools/code-reader/actron-pocketscan-code-reader/603853_0_0/

http://www.harborfreight.com/automotive-motorcycle/diagnostics/can-obdii-code-reader-with-multilingual-menu-98570.html

Thanks for your thoughts.
Class C
  • burlmart's avatar
    burlmart
    Explorer
    Feb 10, 2015
    This is all good - Thank you guys. I am a bit more relieved now that I know where to look and that maybe I can give the gas cap a little longer before the scanner purchase. I will need it someday, anyhow.

    As always, you guys are great!
  • Snowman9000's avatar
    Snowman9000
    Explorer
    Feb 10, 2015
    Burl, the port is under the dash in front of your left leg.
    Our TL came with a spare gas cap that the PO had kept handy. I hear that is the common failure.
  • IAMICHABOD's avatar
    IAMICHABOD
    Explorer II
    Feb 10, 2015
    burlmart wrote:


    I cannot find where the OBD2 receptacle is on the '05 Chevy.


    On my 05 it is located under dash just above the emergency brake lever.
    it is in the center of this pic.

  • D_E_Bishop's avatar
    D_E_Bishop
    Explorer
    Feb 10, 2015
    I bought an HD OBD II reader and it works great. Bought one for each of my daughters. If the problem is the gas cap it will tell you and you can reset.

    Mine CEL will not go out without using the reader reset function. Neither will the light go off in DD#2's KIA. DD#1 has a BMW and I have now idea about that bummer.
  • burlmart's avatar
    burlmart
    Explorer
    Feb 10, 2015
    Thanks for tips. It has 2 trips = 300 mi since CEL came on. Friend took gas cap fat o-ring off 80 mi ago and rubbed it w/ some pool 'n spa gasket stuff - feels pliable.

    I had it run rough once when changing batt as comp reset. That spooked ,me enough not to do it again unless have to.

    The key and 3 pumps has worked on oil service lite, not sure 'bout CEL. I will likely want to know what error I have if CEL STAYS ON.

    Might give one more 100+ mi trip before getting a gauge.

    I cannot find where the OBD2 receptacle is on the '05 Chevy.
  • jfkmk's avatar
    jfkmk
    Explorer
    Feb 10, 2015
    All kinds of sensors will make the cel go on. Best bet is to get it scanned. Most auto parts stores will do it for free. Just beware they are sometimes it geniuses when it comes to using the reader/scanner. I had one tell me the computer module was bad after scanning. I bought an Actron scanner and it turned out the O2 sensor was bad. Replaced it. Reset the code and it's been fine for more than 5000 miles now.
  • DrewE's avatar
    DrewE
    Explorer II
    Feb 10, 2015
    Autozone (and probably some other auto parts places) will still scan for free. It shouldn't be too hard to find one you can finagle parking at.

    As Scott said, there are a vast number of things that can cause a CEL. It basically just means that the engine computer found something amiss somewhere. Reading and interpreting the code is, of course, the best first step towards diagnosis of the underlying problem.

    Since you had difficulty pumping gas, I would inspect the tank vent line. Maybe it's pinched or cracked or sagging or something along those lines. I think it generally is a smaller hose routed along with the gas tank fill hose. Some problems with it may not cause the CEL, but still affect the tank filling.
  • klutchdust's avatar
    klutchdust
    Explorer II
    Feb 10, 2015
    Not sure of the HF unit but I purchased mine around 100 dollars. You can remove battery for an hour or if it's GM try turning on key to on, not start,

    pump accelerator three times to floor slowly then turn key off and remove from lock. Wait a few minutes then restart and check. This will remove annoying service

    reminders and has removed CEL on my diesel pick-up.

    Sometimes CEL needs to run through cycles. Maybe 4 or 5. A cycle is normal use like running errands. The computer needs to reset and then all should be fine.

    You may just have a bad fuel cap. Remove and replace a few times.

    A meter is the best way to go. Once you have the code you can look it up online and see the problem. Everyone should have one to keep the repairman honest.

    If you can plug in a printer, you can plug in a code checker. They also have nice features to read as you are driving. I found my sweet spot for fuel economy

    driving my rig from Minn to Cal after I purchased it and overall just a handy tool to own.
  • ScottG's avatar
    ScottG
    Nomad
    Feb 10, 2015
    There are dozens of things that can make the CEL come on. If it's an ongoing problem then buy a cheap code reader so you can see what it actually is.

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