I'm posting this here just in case it helps anybody else solve the problem where the "ETS OFF" and "Check Engine Light" (CEL) come on.
The "ETS OFF" and "Check Engine" lights came on in my wife's 1996 Cavalier LS Convertible, 2.4L. Otherwise the car ran perfectly. After doing some research here (and thanks to some of the posters here) I did the following.
1. I checked the gas cap to see if the gas cap was tightly fastened. It wasn't. The gas cap was screwed on, but I was still able to tighten the cap about 1/6 of a turn before it started clicking. However, since I was only able to tighten the gas cap about 1/6 of a turn, I thought that there was almost no chance that this would fix the problem. When I restarted the car, the ETS OFF & Check Engine lights remained on. However, some of the posters here said that it takes about 40 engine starts before the error codes clear, or you can just disconnect the negative terminal of the battery for a few seconds, so...
2. I disconnected the negative terminal of the battery for a few seconds and reconnected it. When I started the car, there were no more warning lights. I started the car a few more times and had my wife drive it around for a few days, but there have been no error lights. Problem solved!
Based on what I've read on this site, almost whenever the CEL comes on, the ETS gets turned off, and so those two warning lights usually come on together, which may mislead you into thinking that there's a problem with your Enhanced Traction System (ETS), when in fact the problem is something else. So this solution won't fix all such "ETS OFF + CEL" errors, but this solution is so easy (and cheap) that it may be worth a try.
I don't regularly visit this website, but I promise to post a comment below immediately if this doesn't turn out to be a long-term solution.
Yeah , this was awesome help , I had it on for awhile & nobody knew how to turn it off , I thought my fluids were low , this was alot of help , thanks alot !
I even read a factory recall about something to do with the gas peddle that can ETS off too.
Z doesn't mean last, it just lapped A.