Hey all,

It has been quite some time since I've been on here. Still have yet to replace the TPS as with the wife still unemployed, still can't some up with the kind of money Lexus wants for this part. $417+tax. I would love to be able to do it myself, but it needs calibration from the dealership.

Are Lexus dealerships the only place that could do this? Would a Toyota shop work or be able to work on this? I really figured this to only be around $200-250 based on the part only being about $125 and that it sits right out on front only held in by 2 screws!

 

Maybe a stupid question, but have you tried resetting the ECU? It is a pretty important step that some people forget to do.

 

i am going thru this with my buddies replaced the motor and tps still nothing took the throttle body off my car just to test still nothing i am leaning towards the pedal position sensor now we will see...

 

Was thinking after I posted this it cant be the pedal position sensor because when I swapped my throttle body over it should have worked. I am stumped only thing I can think of now is the ecu. What do you guys think?

 

its easy to adjust the tps with a multimeter. i belive it .62 or.72 volts at closed position and 4.5 volts at full throttle. and you can get a sensor from parts geek for 80 bucks

 

ok anyone fix this problem yet i have ajusted the tps four times swapped the whole throttle body with mine off a working gs and still the same issues could this be the computer?

 

Let me look up my alldata. Ok this is what the allpoint says about the app sensor:

so it could be the ecm. I doubt it is though

 

i have been going thru this problem on my buddies car the code pops up saying its a throttle control motor and the dealer and two shops wanted to change out the throttle body for 1400 plus 500 in labor. i told screw that we can get the motor. got the motor still nothing so i swapped my throttle body in since i knew mine was good. still nothing had me thinking. so i took a meter to everything all the sensors were good and i just replaced the tps. so it i was pretty sure it was the ecu but wanted to be sure. so i took my ecu out and took the keys apart for the chip. the ecu are programed to our keys so i had to swap this so the car would start. swapped it out and wow everything works now. just need to send his ecu out to get repaired for 149.00 plus shipping alot better than 1900.00 though. anyways i would check ecu a lot quicker now knowing this.

 

it was the ecu

 

Really 149.00 to repair an ecu? That sounds really inexpensive. May I ask who does this for that price?

 

I'm actually experiencing this issue right now. I didn't really see what the surefire solution was. Is it the ECU, TPS, or PPS?

 

I have a 98 gs300. My pedal would go dead but when mashed to the floor I would have like 20% throttle. I replace the pedal positioning sensor. It was 235 at the dealer ship. It's the sensor on the backside of the throttle towards the fire wall. Fixed the problem right away From my understanding the sensors get worn down n create a dead spot in them. My pedal would feel dead outa no where when I pressed it like a 1/4 of an inch like at cruising speeds

 

The accelerator pedal has a sensor that is very similar to the throttle sensor on the throttle body, almost identical. However Lexus does not provide any instructions for this sensor to be adjusted, so it has to be replaced if its out of calibration.

I had a problem with my 430 a while back, where the car would start "bucking" while cruising. I'm not sure if "bucking" is the correct term - but basically while cruising at 50-60mph, the car would start decelerating as if I let go of the gas pedal. Gentle push on the gas pedal, and it would start accelerating again. My first suspicion was the TPS sensor, because I replaced it when I did my 100k tune up, but never had it properly adjusted, just did it "by eye".

The first thing I did is properly adjust the throttle sensor on the throttle body. This is very very easy, on the 2GS. On the older models you had to use a voltmeter and feeler gauge, which is clumbersome and virtually impossible to do while the throttle body is on the car. On the 2GS you just hook up a laptop to the OBDII port, and adjust it. You will need an ELM cable (can be had for $10 on ebay) and software that can read generic OBDII data - I personally recommend Scanmaster ELM. It costs a few bucks, but you can use a trial version if you don't plan to use it extensively. I'm sure theres other generic OBDII software as well.

But in my case, while the TPS was a bit out of spec, it wasn't the culprit. The problem persisted, so I had to replace the accelerator pedal as well. I ordered it from Darryl at Sewellparts.com and it was around $130-$140, as usual big savings over local dealerships. Replacement was extremely easy, and the problem went away.

If need be I can find the part number for you guys.

 

The part number would be great.

 

Thanks for the replies. We actually just had the TPS done at the dealership a couple months ago (cost around $400). Do to the calibrating of it, I did not want to attempt this myself, just let the computers at the dealership get it right.

It solved 99% of the issue right off the bat. However after a week or two of driving, we did still notice some similar symptoms (loss of acceleration off the line or while at cruising speed on highway) but at a much less frequency, so it has not completely solved the issue.

The next (and final) item up for change would be the Accelerator Pedal Position Sensor. I am not sure if this is another item that would need to be calibrated by the dealership of if it is a simple swap that I could do and save a few dollars this go around.

I think from our experience, the culprit has been a combination of the two, plus the fact they work together in a series, it's really near impossible to mask which is or is not working properly.

I'd greatly appreciate the part number for the PPS and if it is as simple as myself just changing it out, I believe that should take care of the full problem.