View Poll Results: What mods have you done?
No mods that would effect the idle
66
58.41%
Torque Converter
3
2.65%
Intake w/o ECU
18
15.93%
Intake w/ ECU
11
9.73%
Torque Converter and Intake w/o ECU
1
0.88%
Torque Converter and Intake w/ ECU
14
12.39%
Voters: 113. You may not vote on this poll
Low Idle Investigation
at idle in "D" my TPS is reading 12.5%. Before buying a new TPS, I suggest you test the sensor first. Check the TPS and the Throttle Accelerator Pedal sensor.
also, what is you IAC reading?
a bad PCV will cause rough idle.
also, what is you IAC reading?
a bad PCV will cause rough idle.
Last edited by GS4_Fiend; Aug 2, 2011 at 10:52 PM.
Driver School Candidate
Joined: Jan 2011
Posts: 6
Likes: 0
From: VA
Just to give an update on my situation....it seems that mine has been resolved for now.
I had super low idle issues forever. I had noticed that my voltage would always be super low as well, which I attributed to the low idle not turning the alternator at the speed it should. I constantly had to keep a charger on my battery to keep it fully charged. Even with all my mods, I've never believed that the car SHOULD low idle. I'd always thought that it was an ECU glitch since cars in our gen. seem to have it regardless of mod levels.
Anyway, about a week or two ago I got the dreaded CEL. I pulled the codes and it had all kinds of new codes. They all had to do with the throttle body. I changed out the TPS, and it didn't fix the issue for long since the codes came back. I did some reading and found out that when the ECU sees any of these codes, it shuts down the valve motor on the TB and then the car only idles via that throttle cable. So in essence, you're left driving with two feet to keep the car from stalling. For those that don't know, a NEW TB is $1000+ at the dealer. Luckily I have some great friends and one of them pulled some favors and got me a used one at a great price. I put it on and VOILA!!!!!!!
My car idles perfectly now. No longer do I have to have the A/C on to keep from stalling. No longer is my voltage constantly at 12v at idle, since I now idle where it's supposed to.
Anyway, since the TB has 3 different electronic parts that have to work together to keep the car at idle correctly. I suspect that one malfunction doesn't trigger the meltdown, but 2 or more bring on Armaggedon.
BTW, my VSC lights (both on and off) lit up every time there was a bad TB code. Don't know the correlation of the two, but the car went funky as soon as both those lights would tilt.
Well, I thought I'd share.
I had super low idle issues forever. I had noticed that my voltage would always be super low as well, which I attributed to the low idle not turning the alternator at the speed it should. I constantly had to keep a charger on my battery to keep it fully charged. Even with all my mods, I've never believed that the car SHOULD low idle. I'd always thought that it was an ECU glitch since cars in our gen. seem to have it regardless of mod levels.
Anyway, about a week or two ago I got the dreaded CEL. I pulled the codes and it had all kinds of new codes. They all had to do with the throttle body. I changed out the TPS, and it didn't fix the issue for long since the codes came back. I did some reading and found out that when the ECU sees any of these codes, it shuts down the valve motor on the TB and then the car only idles via that throttle cable. So in essence, you're left driving with two feet to keep the car from stalling. For those that don't know, a NEW TB is $1000+ at the dealer. Luckily I have some great friends and one of them pulled some favors and got me a used one at a great price. I put it on and VOILA!!!!!!!
My car idles perfectly now. No longer do I have to have the A/C on to keep from stalling. No longer is my voltage constantly at 12v at idle, since I now idle where it's supposed to. Anyway, since the TB has 3 different electronic parts that have to work together to keep the car at idle correctly. I suspect that one malfunction doesn't trigger the meltdown, but 2 or more bring on Armaggedon.
BTW, my VSC lights (both on and off) lit up every time there was a bad TB code. Don't know the correlation of the two, but the car went funky as soon as both those lights would tilt.
Well, I thought I'd share.
ClubLexus Stories
Celebrating Lexus & Toyota from Around the Globe
8 Tips for Improving Your Hybrid or Plug-in Hybrid's Efficiency!
Michael S. Palmer
10 Best Lexus Models No One Remembers
Joe Kucinski
TRD Off-Road Premium: Best 2026 4Runner, Except This One Thing
Michael S. Palmer
Top 10 Lexus & Toyotas to Drive Before You Die!
Joe Kucinski
Top 10 Lexus/Toyotas With The LEAST 5-Year Depreciation
Joe Kucinski
Lexus LC500 Convertible Auction: A Preview of Rising Values?
Brett Foote
GX 550 vs TX 550: Best 3-Row Luxury Lexus Family Hauler
Michael S. Palmer
9 Best Lexus Models You Can Buy for Half Price (And 1 You Shouldn't!)
Joe Kucinski
2026 Lexus NX Buyer's Guide: Models, Features, Prices & More!
Brett Foote
Driver
Joined: Sep 2013
Posts: 104
Likes: 0
From: MN
i have now experienced this issue twice. Both times i popped the hood and took the multimeter to read the battery. It reads 11v while car is running. First time it happened i thought alternator died. Replaced alternator and now it happened again. It reads 11v with engine running. Shut off and restart the car. Still low idling around 100-200. After a minute, engine starts to rev up back to normal 500-700rpm.
Checked battery and was now reading 14v still with car running. It looks like it has to do with timing or something. Something is not triggering alternator to charge battery. When battery low, car idles extremely low and often stalls.
so it sounds like at least 2 parts failing in TB
Checked battery and was now reading 14v still with car running. It looks like it has to do with timing or something. Something is not triggering alternator to charge battery. When battery low, car idles extremely low and often stalls.
so it sounds like at least 2 parts failing in TB
Last edited by driver1988; Feb 11, 2014 at 05:55 PM.
Driver School Candidate
Joined: Nov 2017
Posts: 1
Likes: 0
From: California
Low idle 2006 GS 430
Hi everyone,
I bought a 2006 GS 430 a couple months ago with 110k. I took it to service station and had full preventative service done (Timing belt, all seals, tensioner, water pump, spark plugs, all fluids, new radiator). Shortly after I had the low idle issue. Took it back and they cleaned throttle body but it didn’t cure it. So I just had the throttle body replaced ($1100) and I’m still having the same issue; in Drive with A/C off and lights off I idle between 450-500. It’s a little rough but hadn’t cut off. I’ve taken it back to service station (Lexus specialist here in LA) but they can’t figure out the problem over the weekend. It’s still there now, can anyone give guidance/suggestions on what it could be?
I bought a 2006 GS 430 a couple months ago with 110k. I took it to service station and had full preventative service done (Timing belt, all seals, tensioner, water pump, spark plugs, all fluids, new radiator). Shortly after I had the low idle issue. Took it back and they cleaned throttle body but it didn’t cure it. So I just had the throttle body replaced ($1100) and I’m still having the same issue; in Drive with A/C off and lights off I idle between 450-500. It’s a little rough but hadn’t cut off. I’ve taken it back to service station (Lexus specialist here in LA) but they can’t figure out the problem over the weekend. It’s still there now, can anyone give guidance/suggestions on what it could be?
Hi everyone,
I bought a 2006 GS 430 a couple months ago with 110k. I took it to service station and had full preventative service done (Timing belt, all seals, tensioner, water pump, spark plugs, all fluids, new radiator). Shortly after I had the low idle issue. Took it back and they cleaned throttle body but it didn’t cure it. So I just had the throttle body replaced ($1100) and I’m still having the same issue; in Drive with A/C off and lights off I idle between 450-500. It’s a little rough but hadn’t cut off. I’ve taken it back to service station (Lexus specialist here in LA) but they can’t figure out the problem over the weekend. It’s still there now, can anyone give guidance/suggestions on what it could be?
I bought a 2006 GS 430 a couple months ago with 110k. I took it to service station and had full preventative service done (Timing belt, all seals, tensioner, water pump, spark plugs, all fluids, new radiator). Shortly after I had the low idle issue. Took it back and they cleaned throttle body but it didn’t cure it. So I just had the throttle body replaced ($1100) and I’m still having the same issue; in Drive with A/C off and lights off I idle between 450-500. It’s a little rough but hadn’t cut off. I’ve taken it back to service station (Lexus specialist here in LA) but they can’t figure out the problem over the weekend. It’s still there now, can anyone give guidance/suggestions on what it could be?
Thread
Thread Starter
Forum
Replies
Last Post
