it started about two weeks ago, after leaving from a stop,no throttle for a few seconds and both vsc and vsc off lights,came on and went off,now it is happening alot very dangerous.i did a search but did not get a conclusive answer,looks like it might be the throttle position sensor?any ideas anyone?thanks
99 gs400 110000 miles

 

Yep TPS sensor most likely. THey are not that expensive and easy to change.

 

Becarefully though, There are two TPS on this engine. Also you will need a adjust it to 13% throttle when replacing this. It looks easy but it's not that easy.
JPI

 

well removed negative battery cable.left it off over night,problem has not been back,i could not drive more than 5 miles with out the problem.it's been three days?should i still replace tps?

 

If you have access to a scan tool, I would check it out to see if you can retreive any codes.
JPI

 

did that no codes.thanks

 

it's been a week,running like a champ,who knows

 

Most likely the Accelerator Sensor. Just a matter of time before it goes south. I replaced both the TPS and APS just to be on the safe side.

JPI, I swore the throttle angle is 14%, but it has been a month or so since I set mine prior to the S/C install so I could be wrong.

Lee

 

Do you have access to a lexus scan tool?
JPI

 

JPI,

I have scan software on my laptop with the appropriate cables to access the vehicle information such as O2 readings, throttle angle, etc....Works great.

Lee

 

well i replaced the tps anyways,my service manual say's to set it at 15.2% so i did,no probelms yet.
idle feels good with no air or lights on in 90+ weather.