Willgs300

Az- Dave, I had the same codes as you and problems(lights n limp mode) Everything exactly. I ran a ohm test on tps, throtle motor and the assembly lever. All was okay cept the throttle motor. Spent 340 on the part and replaced it. Still nothing same problem. Did u do anything else other then just replacin the motor? For ever1 havin this problem save money and buy a used whole throttle body with tps, throttle motor and assembly lever becuase it seems like it could b any1 of them. I wish I would of done that. ****!!!!

tom steele

i just figured the problem out for my buddy the dealer wanted to change the throttle body for 1900 i told him screw that ill figure it out. started by changing the tps then i tried the throttle control motor with no luck so i swapped my throttle body over knowing mine is good. still nothing so i ended up swapping the ecus out and what do you know works great. so even if its popping codes saying its the throttle control motor it might not be

tom steele

yes this is the same motor for the 400 only difference is the rubber grommet is a little shorter. bought one to check

AZChris

I am so happy to have found this discussion. Driving to friends yesterday, stopped at grocery to get a couple items. Wife (who was driving) stayed in the car with engine/ac running. Leaving the parking lot and proceeding into traffic the car went into "limp mode" and after a minute or two the VSC, VSC off, and engine check lights came on. Stopped at a light and the car was unresponsive. After determining that we could drive by flooring the accelerator we proceeded to the friends house. Stayed for several hours and drove home - car responded normally but with warning lights still on (of course).

Found this thread today and did the ohm test described in the manual on the motor and the two sensors - sensors within spec, but motor gave 5.7 ohms between terminal 3 and 4. Spec is 4.2-5.2 @ 68F. Seems close but the range is quite small - just 1 ohm. The engine was warm and I suspect parts were at ~100F+, but this should lower resistance - yes? The throttle motor makes a low "buzz" with the key on but does operate the throttle when the mechanism is rotated - sounds a bit noisy though, but don't know what 'normal' sounds are.

Disconnected battery and lights are off, car drives normally. (didn't check codes beforehand)

I assume the failure was heat related - sitting in the lot running the AC got something too hot - but perhaps is a sign of pending complete failure.

So, I read that AutoZone will check the computer codes for free (assuming this happens again). I assume there is no way to do this at home w/o special equipment...

I can get the throttle body on ebay for ~$200 or less with all parts - any tips on going this route should I pursue it? Are the ohm tests definitive in identifying failure correctly?

tom steele

i wouldnt get a used throttle body and the ohm range is fine as you can also just use 12 volt to the power the motor then to the clutch assembly to test its working then test the sensor on the other side the throttle position sensor and make sure its sending signal to the computer if it isnt i would try that if it is then get you ecu rebuilt you have to send yours in getting a used one you have to have lexus flash it to match your keys and its not cheap. i found a place on ebay that rebuilds them for 149.00 plus shipping dont call them directly they want 349 that way.

tom steele

might be your ecu check that. i went thru everything on my buddies car only thing that worked was the ecu. lucky we have the same car to swap parts without spending a fortune...

AZChris

An update to my post: Thanks Tom S. for your advice - I had already ordered the throttle body from ebay and it turned out to be from an IS300. The part # for the IS is 22030-46220 and for the GS its 22030-46120. The difference, as far as I could determine, is the accelerator cable position sensor is different (22060-46070 vs 22060-46010 for the GS). The GS computer didn't like the signal from this sensor, although the car started and ran normally. Visually, the lever on the accelerator sensor that actuates the 'limp mode' by mechanically opening the throttle is fixed in a different position. Perhaps the signals to the computer are different as well. Motor and throttle position sensor are identical between IS and GS.

Both sensors and the motor tested normal (this was confirmed by a local shop I took the car to), however the shop said that the accelerator cable position sensor had a reputation for failure. The check lights were always tripped when the engine was hot with the AC running and the car sitting - failure under high heat in engine compartment. When I was checking the voltage range for this sensor with a multimeter at the computer connection it 'glitched' once - losing the signal.

I ordered the sensor from lexuspartsnow and including overnight shipping saved about $80 vs local purchase from the dealer for a new factory part. I restored the original throttle body with the new accelerator cable sensor and the car runs fine now.

The advice from the shop was key in identifying the failing part as all troubleshooting readings were within normal ranges (the initial out-of-range reading on the motor was not repeated later and the conventional wisdom from the shop was that the motor rarely fails - it has it's own trouble codes for the clutch and motor and neither of these were tripped).

Too bad the troubleshooting is not straightforward and the sensors are so expensive...

GS300Rich

Im having the same issue now. Went to advanced auto parts and got the codes pulled, p1120 and 1121. So I ordered a new MAF sensor and of course this didnt do anything. Then I found this thread. Looks like I will be ordering the throttle control motor hoping that this is the cause. If its the throttle lever assembly how hard is this part to install? Im far from a mechanic but im not totally clueless.

Also does anyone have a good diagram of these parts? I know about the throttle lever assembly and the throttle control motor, just looking for the accelerator pedal sensor and throttle position sensor in case I have to resort to fixing those.

GS300Rich

One other thing I would like to mention, my car doesnt just go straight to "limp mode" but rather the pedal becomes less and less responsive until finally in full "limp mode".

Tuanville

My CEL, VSC, And VSC OFF lights are all on, but it does not get limp... Instead the idle is really rough, and sometimes the engine cuts off. When I'm driving, it'll drive rough up until 2000 rpm. Once i past 2000 rpm it runs fine.


Is this the same thing?

45cal1911

I'm having the same issue Tuanville. Going to have autozone pull the codes, but I'm going to proceed with a MAF cleaning and throttle body cleaning to see if that straightens anything out. I will post back with the results.

Agent0024

iTrader: (4)

I'm just guessing without an exact code, but that sounds like a Oil Control Valve malfunction. Those are the exact symptoms that I was having and the code shows that the Oil Control Valve is done for.

Get that OBDII scanner I showed you in the other thread and come back with a code so we can help you.

45cal1911

Just for clarity I'm having the same symptoms as Tuanville.

Had the codes pulled:

P1349 & P1346

1349 Seems to reference the Oil Control Valve

Can anyone help me troubleshoot this problem?

Thx


Update:

Replaced the OCV and disconnected battery to reset ECU. All is now well.

I apologize for posting in this thread as there are numerous threads covering this well know issue.

Thx

DruMnBaSS

iTrader: (1)

just wanted to add to the thread; had the same problem; while driving the car hiccuped and check engine light came on and thats it no throttle. I was able to make it home flooring it at 25mph. This morning i ran through the awesome diagnostic page found here

and found everything to be within spec... oddly enough i took off the intake and the motor responded along to the throttle; go figure the car drove this morning; however the motor does not sound happy at all grinding and buzzing. Going to be my first replaced part here.

Roman.

DruMnBaSS

iTrader: (1)

Great!! i ordered a TB from Ebay go figure... same problem...
ECU next. annoying!

I read something about recalibrating ECU's or key related or something...
can anyone comment on this? can i just buy an ECU off ebay and call it a day?
if you have one lying around gimmy a ring 5618660737 i intend on driving on limp mode till then... sigh!