GoodRevs

I've researched this and I can't find an answer. A year ago I disconnected the battery on my 2003 ES to replace some of the backlight bulbs in the climate console. Upon reconnecting the battery the car would not idle. We needed the car the next day so I brought it to the mechanic. He had it ready the next day and said he the car needed to "relearn how to idle". I've read this "relearn idle" thing before but no one seems to know how to do it beyond saying all you need to do is drive the car and it will relearn on it's own. I did drive the car and it didn't seem to relearn idling.

I need to do a few minor fixes on my '03 ES and I've been putting them off because I'm afraid to disconnect the battery and run into this idle problem again. I've disconnected the battery on my other cars dozens of times and never run into or heard of this type of problem. If anyone has some info on this please let me know; I don't have an FSM for the 4ES so I need some input. Thanks.

idream08

unfortunately i wouldn't call myself the best advice giver for our model because unlike my previous Lexus our 2003 is sort of different. There's others on here who will give more sound and accurate advice. But, I did have a problem that sounds similar to yours. After pulling the battery to replace light my car was sounding like it had engine issues, rpm was every where but as advised on here and mechanic everything has to reprogram. I've pulled battery 5 times since having car, the last time was the only time i can remember where the car appeared to be shaking while idle, moonroof stopped working, amp appeared to not be consistently working, etc...it took 1.5 days to return to normal.

GoodRevs

Just so I understand what you're saying; the car relearned how to idle simply by your driving it for 1.5 days? Not pressing you for info, just trying to make sure we're on the same page here before I go and run into this issue again. Summary = The car will relearn how to idle by simply driving it?

MES3

Hello,

I also have gone through this issue several times with my 2003 ES300. I have found the best way to speed the issue up is to find a gas station that sells 93 gas. It usually resolves my situation in about 1-2 hours rather than waiting 1-2 days for it to figure itself out for some reason. I don't know why it would help, but for some reason it has worked every time that I have done it.

nsghtbrwry

I've encountered this on various 2000+ Lexuses...ES300, ES330, IS300, GS300. They all need to relearn idle on battery disconnect, and when you start up they either idle somewhat erratically, or idle at 200 RPM and it slowly moves up. I remember reading somewhere (may have been a manual, may have been a forum post) that you have two choices:

1. start it up, let it sit there and relearn idle for five to ten minutes
2. hold the throttle to keep it steady at 3000 RPM for a minute or two, which speeds up the process. Obviously better if your car will not hold an idle

Sometimes I encounter a facelifted 3ES that doesn't do this, sometimes they do. The others consistently did this. HTH