Check Engine light
Team Owner
Joined: Sep 1999
Posts: 41,732
Likes: 1,718
From: Springfield MO
I would still want to know what the codes are before simply wiping them out. OnStar should be able to give you the code. If not, dealer/Autobone. If there is an emerging problem with the vehicle, it will be in your favor to have the code stored in memory for the dealer to see. Just wiping it out, or saying Autozone says it was P0XXX will hold little value to them. I don't take Autobones word for it when a customer brings a vehicle to me for a CEL. I want to troubleshoot it for myself. Depending on the code, if their vehicle is in warranty I won't clear it sometimes, this way the dealer can also see the history.
Instructor
Joined: May 2011
Posts: 237
Likes: 3
From: canfield ohio
Just a newbee here. But this happened to me today. Check engine light on. Did the normal things(battery,oil,water stuff), and yes did the gas cap also. Called the dealer and he said bring it right in. Put the scanner in the computor with no apps. Tried it again and the computor thru the emissions evap out of limits. cleared it and away we go. Guess some one didnt tighten the gas cap. Can't think of who that was:::::me. ok now and the computor will not clear itself i was told. learned a lesson here.
Drifting
Joined: Nov 2011
Posts: 1,843
Likes: 330
From: western NY
I'll do the same thing sometimes on customer cars (depending on the code and if the car seems to have no apparent drivability problem), but at least I document what the code was and also document the freeze frame data before clearing it. Now I'll know if it is a repeat problem, or something else if the light comes back on.
Intermediate
Joined: Nov 2011
Posts: 46
Likes: 0
The ecu has "soft" and "hard" codes. The difference is how severe the ecu thinks it is and what the problem it detected is. For an emissions code like a loose fuel cap (small evap leak), it will typically set the light and everytime you run a key cycle through it tests it and for soft codes, the light will normally turn itself off HOWEVER the error will still remain in the ecu's history that a hand held scanner can pull up. A hard code will stay on no matter what, even if the problem is fixxed. Once it's fixxed you can get the code cleared via scanner.
Team Owner
Joined: Aug 2007
Posts: 136,140
Likes: 2,432
From: I live my life by 2 rules. 1) Never share everything you know. 2)
St. Jude Donor '11-'12-'13, '16-'17-'18
As I previously posted, if the condition is cleared and doesn't reappear, the CEL will reset itself OFF after half a dozen ignition cycles or so.
The code (as vetteboy07 points out) will remain if it's important enough. A loose gas cap won't be one of 'em...
