Low Idle issue resolved! '00 LS
Thread Starter
Intermediate
Joined: Sep 2005
Posts: 407
Likes: 38
From: SC
Low Idle issue resolved! '00 LS
I finally got my car back from the dealer for the infamous low idle issue. They replaced the throttle body (luckily under warranty). When I picked it up, it still had the same problem
. Low idle at 400 RPM unless the lights or A/C was on. Upset that they released it to me without confirming it was fixed, I returned it to them and firmly asked that they resolve the issue. 2 days later (and a ES350 loaner 
), they said the contacted a Lexus engineer and found that the ECM had to be reprogrammed for the new throttle body. There was no TSB on it and that's why it took so long to diagnose.
Well, needless to say it worked! The idle remains at 700 RPM no matter what the condition is. Throttle response is also MUCH better. I'm a happy camper as it now runs perfectly! I imagine a through cleaning of the TB will work, but the reprogramming was the key in my case.
Cheers!
. Low idle at 400 RPM unless the lights or A/C was on. Upset that they released it to me without confirming it was fixed, I returned it to them and firmly asked that they resolve the issue. 2 days later (and a ES350 loaner ), they said the contacted a Lexus engineer and found that the ECM had to be reprogrammed for the new throttle body. There was no TSB on it and that's why it took so long to diagnose.Well, needless to say it worked! The idle remains at 700 RPM no matter what the condition is. Throttle response is also MUCH better. I'm a happy camper as it now runs perfectly! I imagine a through cleaning of the TB will work, but the reprogramming was the key in my case.
Cheers!
Wow, thats great news. Hopefully it will stay that way. I had the same problem with my 98LS400, and now with my GS. Strangly, my current LS430 with the same engine doesnt seem to have that problem.
Mine does idle low under the same situations of no a/c .
I never changed my throttle body since i have owned it and only happened last summer. Also my throttle body is clean though.
I never changed my throttle body since i have owned it and only happened last summer. Also my throttle body is clean though.
can lead to electrical issues, esp. if u have a dead/dying battery (alternator isnt putting out enough voltage), heavy steering, and the car bogging down when accelerating from a stop.
Thread Starter
Intermediate
Joined: Sep 2005
Posts: 407
Likes: 38
From: SC
What was strange is that when it was under electrical load (i.e. lights on) the idle would go up. (Always ran great at night). I had cleaned my TB also but with limited results as it would seem to revert back after a day or so. What I found interesting is that after the new TB was installed, the condition was the same until after I returned it and they reprogrammed the ECU/ECM.
The stealer told me that TB's can go bad....something about the throttle plate sticking and that a mild cleaning won't do much good. You would have to disassemble most of it to get to the areas that would cause the sticking. Right.
Grand, it's possible that the TB issue was resolved with your car (430), even though it's the same motor. I truly feel that this is a common issue with these cars that Lexus is not admitting... just too many of us having this problem....
PD, your right about the ramification of having a idle thats too low. The difference in throttle response is HUGE...no hesitation whatsoever
I didn't realize what a major impact it could have on performance. I actually thought I was saving gas with a lower idle. I probably was because now I find myself stomping on the gas now to pass all the bimmers!
The stealer told me that TB's can go bad....something about the throttle plate sticking and that a mild cleaning won't do much good. You would have to disassemble most of it to get to the areas that would cause the sticking. Right.
Grand, it's possible that the TB issue was resolved with your car (430), even though it's the same motor. I truly feel that this is a common issue with these cars that Lexus is not admitting... just too many of us having this problem....
PD, your right about the ramification of having a idle thats too low. The difference in throttle response is HUGE...no hesitation whatsoever
I didn't realize what a major impact it could have on performance. I actually thought I was saving gas with a lower idle. I probably was because now I find myself stomping on the gas now to pass all the bimmers!
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What was strange is that when it was under electrical load (i.e. lights on) the idle would go up. (Always ran great at night). I had cleaned my TB also but with limited results as it would seem to revert back after a day or so. What I found interesting is that after the new TB was installed, the condition was the same until after I returned it and they reprogrammed the ECU/ECM.
The stealer told me that TB's can go bad....something about the throttle plate sticking and that a mild cleaning won't do much good. You would have to disassemble most of it to get to the areas that would cause the sticking. Right.
Grand, it's possible that the TB issue was resolved with your car (430), even though it's the same motor. I truly feel that this is a common issue with these cars that Lexus is not admitting... just too many of us having this problem....
PD, your right about the ramification of having a idle thats too low. The difference in throttle response is HUGE...no hesitation whatsoever
I didn't realize what a major impact it could have on performance. I actually thought I was saving gas with a lower idle. I probably was because now I find myself stomping on the gas now to pass all the bimmers!
The stealer told me that TB's can go bad....something about the throttle plate sticking and that a mild cleaning won't do much good. You would have to disassemble most of it to get to the areas that would cause the sticking. Right.
Grand, it's possible that the TB issue was resolved with your car (430), even though it's the same motor. I truly feel that this is a common issue with these cars that Lexus is not admitting... just too many of us having this problem....
PD, your right about the ramification of having a idle thats too low. The difference in throttle response is HUGE...no hesitation whatsoever
I didn't realize what a major impact it could have on performance. I actually thought I was saving gas with a lower idle. I probably was because now I find myself stomping on the gas now to pass all the bimmers!
It is very true that running your lights will resolve the idle issue... I've also noticed the low idle issue to be more evident when its humid/hot outside.
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Thread Starter
Intermediate
Joined: Sep 2005
Posts: 407
Likes: 38
From: SC
You (they) are right, there is no TSB. That's why they had to place a call to Lexus engineering. TSB's affect their reliability ratings. Why would they do that?!
The dealer also originally told me that everything was OK, that the tach was off! I laughed at him and told him that was impossible due to the change during load. I wrote a 2 page letter to the manager describing my frustration,
telling them that I don't care how long I had to leave the car, but I wanted it fixed. An apology from the SM and 2 days later, it was resolved.
I will try to find our exactly what programming was done and post. If we communicate exactly what the issue is to them, they hopefully have no choice but to fix it. My dealer was very cognizant of the impending survey that was to come my way from corporate!
Personally, this was a very important fix as the overall performance of the car is enhanced besides the idle increase.
Cheers!
The dealer also originally told me that everything was OK, that the tach was off! I laughed at him and told him that was impossible due to the change during load. I wrote a 2 page letter to the manager describing my frustration,
telling them that I don't care how long I had to leave the car, but I wanted it fixed. An apology from the SM and 2 days later, it was resolved. I will try to find our exactly what programming was done and post. If we communicate exactly what the issue is to them, they hopefully have no choice but to fix it. My dealer was very cognizant of the impending survey that was to come my way from corporate!
Personally, this was a very important fix as the overall performance of the car is enhanced besides the idle increase.
Cheers!
Rookie
Joined: Apr 2009
Posts: 31
Likes: 17
From: Houston TX
So did you ever find out what exactly they reprogrammed? i think my 2000 is doing the same thing apprently the TB was replaced under warrenty a while ago, i just got the car, and it seems slow right off the line once it hits about 30 watch out its quick! is this normal i know they dont get to the rated torque till higher rpms but what exactly does the torque curve look like? thanks!
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