Warning! Accelorator Goes Dead On Ls400!

[llexus05]

Driving down the freeway in my 2000 LS400 at highway speeds the accelerator went COMPLETELY dead - nothing on the other end of the accelerator. The car continued to run and coast and everything looked and felt fine (lights, radio, etc) - only there is no way to accelerate or even maintain speed. Check engine light came on and of course the VSC. Correction, if you mash the pedal ALL THE WAY to the floor that car re-engages and has the same affect as flooring it. Therefore, either you're coasting or taking off like a rocket. NOT GOOD when you're in traffic!

This happened about a month ago and comes and goes. The car drives fine for a few days then suddenly this occurs. The check engine light and problem may last a day or even several days. Replaced the MAF sensor (about a ten minute job), no fix.

Has anyone heard of this? Any ideas?

[cardona6569]

I would check then in the Throtle Body area, clean all that up, if it persists, you may have to replace a sensor somewhere, since it comes and goes it seems to indicate its an electromechanical problem. Or a wore parts in the fuel linkage system. Place the scanner and see what it says. It it does not point to any component then it is something mechanical or loose in the linkages. C

[landar]

Just a wild guess but maybe its your TPS (Throttle Position Sensor)?

[alsalih]

What you’re describing is a typical symptom of the throttle control motor going bad. On the ’98 and newer models you have an electric motor attached to the side of the throttle body which controls the opening and closing of the butterfly as opposed to the older and more reliable method of using a direct cable. The electric motor retails for just for around $160 last time I checked. Let us know how it goes.

[1990LS400]

What you’re describing is a typical symptom of the throttle control motor going bad. On the ’98 and newer models you have an electric motor attached to the side of the throttle body which controls the opening and closing of the butterfly as opposed to the older and more reliable method of using a direct cable. The electric motor retails for just for around $160 last time I checked. Let us know how it goes.

Yep, you got it right.

[llexus05]

The throttle control motor is a DIY item?

[dunnda]

What you’re describing is a typical symptom of the throttle control motor going bad. On the ’98 and newer models you have an electric motor attached to the side of the throttle body which controls the opening and closing of the butterfly as opposed to the older and more reliable method of using a direct cable. The electric motor retails for just for around $160 last time I checked. Let us know how it goes.

Can you tell me where is this located?

[llexus05]

Scheduled an appt at a local import shop. I'll let everyone know how this turns out.

Thanks for all the input!!

[92silverls400]

Scheduled an appt at a local import shop. I'll let everyone know how this turns out.

Thanks for all the input!!

I also have a 2000 Ls 400, had the same problem that you mention, was on the freeway to southern California, just got off the freeway, rolled across the intersection, stopped and turn off my engine, restarted it, and continue on my way. went to Lexus Dealership the next day and had my whole throttle body unit replaced. Parts $999.67 Labor $105.60 also gasket, throttle body $19.12 Thank god for extended warranty!!!! This was the 2nd time that it happen, the first time it happen, the dealership in Northern Ca. could not or did not find cause of problem.

[llexus05]

Just heard from the shop and they identified the problem. Throttle Position Sensor - TPS. Other throttle related components tested to spec.

Otherwise, they performed a complete inspection and were impressed with the vehicle. They said the LS's are known for being "extremely solid cars". Yeah LS400! I have to say that at 140k miles there are few cars I would rather own with 1/8th the miles.

Any quesses on what the TPS replacement will cost?

[alsalih]

Interesting info thanks for sharing that. I’m kind of surprised because the TPS will normally trigger a check engine light when it fails and then the car would go into the fail safe mode you noted. You did get the check engine light but it appeared to clear up. The TPS is not expensive and replacement is fairly easy except that they need to clock it (adjust it) right in order to get the correct idle speed. Please let us know if that does in fact fix it your problem.

[Wes-Lexus]

Interesting info thanks for sharing that. I’m kind of surprised because the TPS will normally trigger a check engine light when it fails and then the car would go into the fail safe mode you noted. You did get the check engine light but it appeared to clear up. The TPS is not expensive and replacement is fairly easy except that they need to clock it (adjust it) right in order to get the correct idle speed. Please let us know if that does in fact fix it your problem.

I just had to replace my TPS and it still stalls. Do I need to replace my computer? OH MY!! 1100.00?

[Ms.Diana]

Driving down the freeway in my 2000 LS400 at highway speeds the accelerator went COMPLETELY dead - nothing on the other end of the accelerator. The car continued to run and coast and everything looked and felt fine (lights, radio, etc) - only there is no way to accelerate or even maintain speed. Check engine light came on and of course the VSC. Correction, if you mash the pedal ALL THE WAY to the floor that car re-engages and has the same affect as flooring it. Therefore, either you're coasting or taking off like a rocket. NOT GOOD when you're in traffic!

This happened about a month ago and comes and goes. The car drives fine for a few days then suddenly this occurs. The check engine light and problem may last a day or even several days. Replaced the MAF sensor (about a ten minute job), no fix.

Has anyone heard of this? Any ideas?

DUDE!!!!!!!! OMG!!!!!! I just posted a bulletin for the same problem!!!!!!! It is sooooooo scary!!!!! I don't have clue what to do either if you've come to solution yet..... PLEASE LET ME KNOW!!!!!! I have a 2000 gs400, and yes, the problem comes and goes...not cool when you have kids in the car!!!!! Very scary!!!!! Please let me know what you did to fix the problem.....

[SKperformance]

The fix is to replace your tps sensor , most time it needs to then be calibrated at a dealership with their tool.

[llexus05]

AND THE RESULTS ARE IN

The shop replaced the TPS. They performed some calibration and I have the car back. It's running fine and there is no sign of the problem.

Total cost to run check engine light codes, test throttle components, replace TPS and calibrate was $502.00.

Thanks to everyone that posted! Hopefully this thread will help someone else along the way! Better yet, hopefully no one else ever has this problem!

[alsalih]

Thanks so much for updating us. Please let us in know in a week if that does in fact solve the problem, I'm very curious to know!