ted920

Fellas:

I have been having some issues with the car recently where the car hasn;t been running correctly and then the Check Engine light and VSC On / Off lights came on then shut off.

I posted about this previously and everyone determined that it was most likely a Throttle Position Sensor (TPS) issue. It was recommended to purchase a new TPS from Steve Ganz and then replace it since it only requires the removal of 2 screws.

I bought the replacement TPS and hooked it up. When I started up the car, all the lights came on and there is absolutely no throttle response. Absolutely NONE!!!

Check engine light, VSC ON / OFF Buttons are all on.
I put the gas pedal down all the way and have about 1% response. The car is completely undrivable.

At this point, I really regret trying to replace the TPS on my own rather than taking it to the dealer.

Did I miss something about replacing the TPS? I unscrewed 2 screws, disconnected the TPS, replaced the TPS and re-connected it and have all these problems.

I replaced the old TPS but same exact problem.

I even disconnected the battery, thinking maybe the ECU needs to reset but same problem.

Obviously something is wrong here.

Any ideas?

Did I do something wrong?

I really don't want to have to call AAA to tow the car 30 miles to the dealer. I'd rather just drive it on my own.

Thanks,

Ted

TLW

Ted

dont you have to adjust the throttle % or something

the labor part i know you can do but there is part with a computer

TLW

https://www.clublexus.com/forums/sho...=calibrate+TPS
https://www.clublexus.com/forums/sho...&highlight=tps

ted920

Is there anything I can do to get the car to work well enough to drive to the dealer?

Can I adjust anything here on my own so that I get some throttle response back the way it was before I started this?

Ted

DaveGS4

iTrader: (2)

Ted,

I don't know the answer to your problem, but thought I'd throw out one other idea. My Lexus dealer has one mobile mechanic on duty (full Lexus Tech) that travels to customer locations.... I've used him one time in a similar situation.

If you can't get a solution here, might be worth calling to see if they have a similar service. Most definitely worth it for piece of mind for me on not getting aero parts screwed up by a tow.

TLW

https://www.clublexus.com/gallery/sh...0/ppuser/21704

mdwtexas

Same thing happened to my car..... it is the throttle body. Took the dealer forever to figure out. They replaced the whole computer system, throttle sensor , and still same problem. After they replaced the throttle body it worked perfect.

gserep1

Hello,
I have a 99 GS4, and I also have a hand held scanner. I am sure you have a code that needs to be reset before the throttle will respond to the pedal. There is nothing to adjust, since it is all electronic.

Whenever I clean my throttle body, it requires me to run the engine without the black air intake hose from the filter in place. I remove the hose, and spray the throttle body, and then run it. That sets a code immediately for no air flow past the sensor near the air filter. Your throttle body is controlled by an electric motor on the side of the throttle body. The TPS in conjunction with the computer tells the motor how far to open the electric motor, which allows air into the intake at the rate it needs for that specific throttle position.

Disconnecting any of the above mentioned components and running the engine breaks the electrical continuity between them, and places the system in default....(no throttle response, AND a check engine light. Even if you replace the wire you removed, it still has set a fault that must be reset. Removing the ECU 1B fuse also does not erase computer codes. You had an electrical fault before you installed the TPS, so that code has to be reset.

I do my cleaning, and then use my scanner to reset all codes, Then the unit responds properly to the throttle pedal, and the check engine light goes off..

It doesn't seem possible that your throttle body and computer have gone bad. I finally decided to buy my scanner after I used one like it at AUTOZONE to check codes on another car I have. Now I wouldn't be without it. I think it was about $110.00, and it has paid for itself in the times I have not had to go to the dealership to get codes read. I have been able to diagnose codes in all 4 of my OBD II computer equipped cars.

Warning.... once the codes are cleared, the computer has to learn all the inputs from the engine again, and it takes awhile before all the systems come back online. Doing an emissions test prior to a full reset will cause a failure in the "MONITORS" section of the emission system. The MONITORS reset will take driving the vehicle for as long as a week before it all comes back online. The EVAP purge is the hardest to set..it took me 2 weeks for it to reset.

Give the reset a try, and if nothing else is wrong, it should run correctly as soon as the engine is restarted.

GOOD LUCK!

TLW

where to buy for $110

all the ones i have seen are $500+

morris

iTrader: (2)

I've actually seen them for a little under 100.00 at advance autoparts or maybe it was autozone.

so 110 isnt out of line

ted920

Since I don;t know how to use this scanner and fix these code problems, doe sit mean that there is absolutely nothing else I can do?

Ted

TTurboPimp

iTrader: (12)

Dude, take your car to the dealer before you really mess something up! Im all for DIY projects, but its obvious that you are not going to be comfortable with doing this. Cut your losses and get the car to a dealer where they will rape you, but it will be fixed correctly. Just my thoughts!!

ted920

Looks like thats what I'm gonna have to do.

GS3Tek

iTrader: (8)

Ask them if they can repair it for you under "goodwill gesture" Once in a while when they see that you're a good customer of the dealer, they will waive this for
Wouldn't hurt to ask.

My problem was also the tps, all lights on, but no response.

chuckb

that sucks Ted. can you get it to autozone for them to reset it? maybe someone will let you borrow or rent a scan tool?

was it like this before you switched it out?