Just happened on my GS400 on a hill in the middle of Downtown Seattle. I'm still covered under a extended warranty. They called me stating it was the Acceleration Pedal sensor failing.


Seems to be a regular problem...

 

Id be interested in knowing if they actually just replaced the ACC Pedal Sensor or the entire Throttle Body.

On mine when they pulled the codes, they told me the exact same thing: Accel Pedal And/Or Throttle Position Sensor failure.

Now...with that being said, Im still using my Old ACC Pedal and TPS sensors. The new TPS Sensor I bought is still sitting in its box because once you open the package you cant return it.

Anyway you can ask them or check the invoice to see what was really done?

Thanks - David

 

They pulled the code, P0121 and I guess they only replaced the throttle position sensor. Here's what they wrote:

RAN CODE TEST. FOUND P021. MONITORED DATA LIST. FOUND THROTTLE POSITION SENSOR IS SLOW TO RESPOND. INSPECTED WIRING AND ELECTRICAL CONNECTIONS - OK.

R/R THROTTLE POSITION SENSOR AND ADJUSTED TO SPEC. CLEARED CODE AND RETEST DROVE. VEHICLE ACCELERATES/DECELERATES PROPERLY AT THIS TIME.

I'm hoping this solves the problem. I asked them about replacing the electrical motor under my warranty but they said they couldn't unless the part, "failed".

 

Ok...Im pretty sure mine was Code 0121 also.

Here is the deal...the TPS Sensor is on the front right part of the Throt Body and is attached to the rod of the actual Butterfly valve on the Right side of the Throt Body, that Butterfly valve is Opened and closed by the Electric Motor. The Electric Motor is controlled by the ECU via the signal sent to the ECU by the Accelerator Pedal Sensor which is on the back side of the Throt Body. If the Motor malfunctions is wont move the butterfly valve which will then give the code that the TPS Sensor is bad...because the ECU see's the ACC Ped Sensor signal, but no signal from the TPS.

Keep in touch and lemme know if the TPS in your situation fixed things.

Thx :-)

 

Yeah, I will definitely keep you updated if it happens again. If that doesn't fix it I'm going to be speaking to someones manager at Lexus lol.

What you said makes sense because this happened to me about a month ago in the middle of the night. I wasn't in a position to wait for a tow truck so I disconnected the battery (resetting the motor like you said) and everything worked fine. When I brought it in they said no codes were stored and they couldn't find the problem.

The second time it happened, a couple days ago. I could almost feel something was wrong. I was driving up the hill slowing down for the light when I noticed a really rough down shift. I slowed down for a second light and had the same rough down shift followed by the cel, vsc light, limp mode.

 

same time happen to me on the christmas eve....ordered this part no 22060 46020 Lever Assy, Throttle from Toyota, Japan...cost me USD450 to shipped it to Malaysia...now everything works great

 

thats what i replaced also and everythings working fine

 

Lever Assy ?

Ive done a pretty exhaustive search on the net and cant find this part number. Is this the motor + gear assembly that opens/closes the throttle butterfly valve?

lemme know please.

 

Mine happened very randonmly for a month or so, then got worse. I unhooked the battery a few times, which would *fix* things for a few days. when I replaced just the TPS the prob went away for a few days, and then is came back in force.

If it happens at all after the TPS, get the motor...its a VERY easy fix...no adjusting of any sensors, just 2 screws and it comes off, and he new one on.

:-)

 

Today at 82,591 miles the engine light proceeded by the VSC light and the VSC off light came on my 04 GS300...the car didn't go into "limp moede"...the car kept driving fine for 9 more miles until I got home. Nothing happened!

However, about 2+ months ago the car started limping, it wouldn't accelerate, it just started dieing. I managed to pull over in a rest stop, shut the car off and turn it back on and the car ran fine there after. Took it to the dealership and it didn't pull any codes, the guy told me nothing was wrong according to the scanner, so I drove off.

After reading this whole thread, I've learned that people have spent tons of money trying to fix this problem and more often than not, the problem was fixed by replacing the TB Electric motor. I live in Germany and buying this motor at the dealership is not an option, the euro to dollar exchange is not favorable for us Americans, so I'm thinking about buying the motor next week when I travel to the US. Hopefully I have time to check the other sensors mentioned on this thread, but I doubt it, maybe it will help me determine what the real problem is and save me some money.

Anyhow, since my car didn't limp home today, could it be something other than the electric motor? after all, the majority of the people on this thread claim their car started acting up, but mine didn't, so i'm not sure. What do you guys think?

 

This thing is getting ridiculous. So tired. Changed TPS and MAF already and still limping home. Luckily I take the train to work so I drive 1.5 miles then train it. One time I thought it was fixed. Drove for 30 miles then went back on. Codes are P1120 and P1121. I have cleaned my throttle body twice as well as my SRT Intake. I'm so exhausted.

Next step is changed the Lever Assembly.... I'll keep you guys updated. This year has been terrible. I hate how this problem happens so much but yet solved different ways with the same codes.

*sigh*

 

I think this is a hit and miss type deal and perhaps differs by the year of the car...
I tried searching for the throttle control motor and couldn't find it in Carson's web site, I even used the part # provided on this thread to no avail...i wonder why it's not working....

 

People :-)...On Page 3 of this thread, I posted a few different mfgrs and Part numbers for this Motor. Also a pciture..I will do so Again here:

The Lexus OEM Part NUmber:89672-30020 = $293.54 from Lexus Dealer
(Confirmed Arrowhead Lexus of Arizona, Aug 28, 2009)

Lexus name: "Throttle Control Motor" (Official part name)

Other part name aliases: "Idle AIR control motor" -or- "Idle AIR control valve motor"

Here are some Non-Lexus OEM Part Numbers:
AIRTEX: 2H1145
STANDARD MOTOR PRODUCTS: AC555
WELLS: AC4194

Now...As Ive said before, many LEXUS Dealerships seem to have dumbies working at the parts counter...I have NEVER been satisfied with 4 Dealerships here in AZ...all they want to do is replace parts, then see if it fixes it...its like they are untrained....at least here...which is why I started this thread...I got fed-up. In my case it was 100% this electric motor.

 

Look at my last post...if your car is in LIMP mode, where the engine ONLY responds when you Literally Floor the Gas pedal, then its NOT the MAF...Its most likely the Elec Motor in my previous post.

What is this "Lever Assembly" people are mentioning? Where is it? I have a throttle Cable going from my gas pedal to the back of the Throttle Body...are your cars 100% Drive by Wire? (no throttle Cable)?

 

Been driving about a week since the TPS was swapped out. No issues so far.