az-dave

Get some close-up photos of the plugs for those modules, Im not sure if they are compat. I know 98-99 are, and I think thru 00 and maybe 02.

Id honestly take it to a dealer, tell them you replaced the TPS and the entire TB, so you know its neither, pay them $135 for diagnosing, and see if they can tell if its the ABS/VSC, the Yaw or the main ECU.

Since your saying it runs ok for a little while after clearing codes, its leaning me more towards one of the ECU's, or possibly a completely different problem thats for some stupid reason manifesting itself with the Limp mode (basically throwing wrong code)...maybe O2 Sensors, or something else.

I think if it was the Yaw sensor (which may be incorporated in the ABS/VSC module, I really dont know) that it would be limp mode always.

I really really dislike the dealers, but from everthing youve done, I think its the way you may need to go.

az-dave

ihiryu: What are ALL of the codes you are getting?

One last thing to check is the Mass Air Flow sensor, Air filter, Air Tubes and the connections...If the MAF sensor is bad, it would be detecting a different air flow rate than the TPS sensor suggests which may cause the TPS/ACCL Pedal codes to be thrown. Worth a shot.

Also, if you push the pedal to the floor in limp mode, does it allow you to accelerate to some degree?

When it goes from "good" to "bad" does it happen when engine is only fully warm/hot, or even if dead cold?

When it goes into limp mode, does it sputter for a few moments, or go straight into limp mode?

ihiryu

iTrader: (7)

1120, and 1121.

Yes last ten percent I get some throttle.

Unfortunately there's no temperature difference, it randomly happens.
Doesn't sputter at all, goes straight up limp mode.

GS4_Fiend

iTrader: (22)

To the guys that already change all the Throttle body related components and still got the damn trouble code. You probably need your PCM to be reflashed to fix the problem. That's assuming all the wire integrity from component to PCM are good.

ihiryu

iTrader: (7)

Replaced the Yaw Sensor, no dice. Put the old sensor in, and the lights are come on everyday but the car is drivable.

I don't know what else to replace.

ihiryu

iTrader: (7)

Replaced the yaw sensor, AND the ABS/VSC ecu under the dash.

So entire TB with all sensors, yaw sensor, abs/vsc ecu. Is there another module somewhere else that I'm missing??

az-dave

The Main ECU and all the wires to and from it...thats all thats left...UNLESS you got a used TB with the exact same problem as your old one....but I thought you said you also tried replacing the TPS and Lever Assembly as well ???

Im thinking youve got a wire/harness problem...unless for some reason Bad signals from the MAS Sensor or O2 Sensors are somehow throwing the TPS/ACC PED codes...

honestly, as much as I hate to say this: Its time to take to a Lexus dealer, tell them youve replaced the entire TB, the ABS/VSC module, the Yaw sensor, and pay them $135 to diagnose the problem.

When they know youve already done so much, it will be difficult for them to say "Oh, its the TPS Sensor"...

BTW: Where was the Yaw sensor?

ihiryu

iTrader: (7)

Yeah, a friend of mine is at the dealer now with the car since I had to work. I talked to the tech over the phone..didn't seem like the brightest guy though.

The Yaw sensor sits under the center console. Once you remove the center console you'll see two sensors. The front one (closed to the engine bay) is the Yaw sensor.

az-dave

So your basically stuck now with a car thats going into Limp mode and youve tried replacing virtually everything pertaining to the entire VSC/TB system

Please confirm:
1) You tried installing a brand new TPS - on both Old and *new* TB ?

2) You tried installed a Brand-New Lever-Assembly Accel pedal Sensor - on both old and new TB?

3) You Tried installing a new/or used VSC/ABS Control Module on both Old and new TB?

Do you think there is a possibility that the other entire TB you installed had a bad Throttle Motor?

The reason Im asking those questions is maybe the replacement throttle body has the same exact problem as your old one...it is possible for the shaft and gears to corrode or be sticky. Its kind of a strange set-up when you take the Throttle Controller Motor off you can see what I mean.

In my case, the Throttle controller motor ended up being the culprit...and that seems to be one piece you didnt actually try replacing new.

I would try and suggest its a Mass Air Flow sensor or O2 Sensor, but the codes your pulling are specific to the Throttle TPS and Accel Pedal. And I think if the Mass Air was off youd throw a different code, such as running Lean or Rich...

If its not the Throttle Control Motor, your really left with wires or main ECU...there isnt much else....its a loop-feedback-system, so a problem in ANY part of the throttle body system leads to Limp mode, and can cause that same code...stupid if you ask me, and may be a reason Lexus Dealers seem unable or unwilling to diagnose...it may be virtually impossible to accurately diagnose from the codes without actually swapping parts.

BobaDrift

I solved my codes by changing out my entire throttle body.
With original TB I changed the motor controller and it didn't alleviate the problem.
Instead of purchasing and changing the lever assembly I just changed the entire throttle body.

I'll be posting up my pretty much brand new motor control unit for sale in the classifieds this week if anyone is interested.

Goodluck to those that have yet to solve their vsc and vsc off lights - limp mode situation.

az-dave

So it was most likely the Lever Assembly, BUT...due to the gears and shafts inside the TB, its possible the old TB was corroding causing the gears or shafts to stick or have a lot of friction, which then leads to the code getting thrown.

In your case, did your code related to the TPS sensor specifically or the Accell Pedal and TPS sensor?

Thank for the update.

-David

Tuanville

I also solved my problem. Cost 1,823.20

Replaced the main ecu.

I should've known better, when I checked the terminals for the accelerator pedal sensor on the ecu. It was out of spec. I just wanted to hope it wasn't, but it was....

Took it to the dealer and they said my old ecu was remanufatured and not an authentic Lexus ecu.

Car runs niiiice now.

GS4_Fiend

iTrader: (22)

Should have read my previous post as i did mention.

Tuanville

Too late... =]

az-dave

Sorry to hear it was the main ECU.

This is precisely why I HATE HATE HATE the dealers. You pulled Codes specific to the TPS and Accel Pedal Sensor, not the main ECU. And Lexus cant find that without gouging you multiple times? Pisses me off.

Any rate, Once you didnt have luck with the Lever Assy, VSC/ABS module or throttle Motor I knew it was bad wires or bad ECU...in this case Bad ECU probably easier fix than bad wires.

Glad fixed, sorry it presented with such a bad set of symptoms that even stumped dealer (Ive yet to have dealer actualy suggest proper fix even when paying their ridiculous diag fee.)

Enjoy the vehicle now...it will last a long long long time. I have 255K miles and it still runs awesome and strong.