check engine light came on but goes back off

john1983 · Post by **john1983** » January 15th, 2011, 8:39 pm

ok so today i started my car after it sat for a little while excluding yesterday start but i noticed while it was warming up the engine light was on and it wasnt on last time i drove it but when i tapped the gas pedal the light turned off as the rpms returned back to idle could any one help with ideas of what this could be

Newfie_dan · Post by **Newfie_dan** » January 15th, 2011, 9:06 pm

pull the codes that will tell you for sure.

john1983 · Post by **john1983** » January 16th, 2011, 2:49 pm

ok but y would the light go off though thats what kinda confuses me

mikeinaus · Post by **mikeinaus** » January 16th, 2011, 3:00 pm

you should have pulled your codes before you even posted here. your question is retarded...

Ryan · Post by **Ryan** » January 16th, 2011, 3:04 pm

Its called a soft code. Sometimes the light doesn't even come on, and you have a code. It if comes on and goes off, it remembers it for a few days.

john1983 · Post by **john1983** » January 17th, 2011, 10:16 am

thanks ryan

wytbishop · Post by **wytbishop** » January 17th, 2011, 10:45 am

Many codes are not stored at all as Ryan has alluded to. Some codes will only cause the CEL to comeon while the condition that causes it exists. If the condition corrects itself the the light goes out and the code is not stored. Other codes will cause the ECU to revert to a sort of "safe mode" and will be stored until the ECU is reset. If they are not corrected they will be displayed again as soon as that condition arrises again.

Ryan · Post by **Ryan** » January 17th, 2011, 11:01 am

wyt is right, sorry I wasn't too clear. codes that are from an "on/off" malfunction as opposed to an "out of range" malfunction are stored differently. If you unplug your IAC, CEL will come on, plug it back in, it will go off and it won't remember it was ever not there.

Then, if your O2 reads out of range, or the two are not in agreement, etc, it will remember that condition for awhile.

MrMazda92 · Post by **MrMazda92** » January 17th, 2011, 5:08 pm

This literally just happened to me as well. I threw a 12, which I can't remember atm... I'm checking it now. I pulled over and pulled it immediately, but like a dumbass I forgot to unjump ten/ground before driving home. Thankfully it was ~1 mile, but it was the most unpleasant mile Ive ever driven in an mx3.

john1983 · Post by **john1983** » March 5th, 2011, 3:13 pm

could the code have to do with our ecu learning ability seems the battery died completely and it was relearning just a thought

chrome730 · Post by **chrome730** » March 5th, 2011, 9:55 pm

john man the best thing is to pull the code before you post questions on here. A SELECT FEW ARE BRUTAL ON HERE. LOL. no i love these guys.

How long has your car been un hooked from a battery.

Flyer · Post by **Flyer** » March 5th, 2011, 10:09 pm

My check engine light came on, so I checked under the hood and the engine was still there...

mikeinaus · Post by **mikeinaus** » March 6th, 2011, 1:20 pm

Flyer wrote:My check engine light came on, so I checked under the hood and the engine was still there...

Zing!

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check engine light came on but goes back off

check engine light came on but goes back off

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Re: check engine light came on but goes back off

Re: check engine light came on but goes back off

Re: check engine light came on but goes back off

Re: check engine light came on but goes back off

Re: check engine light came on but goes back off

Re: check engine light came on but goes back off

Re: check engine light came on but goes back off

Re: check engine light came on but goes back off

Re: check engine light came on but goes back off

Re: check engine light came on but goes back off

Re: check engine light came on but goes back off