Calling all 03-07 LX470 owners, VGRS survey, please read! (2 Viewers)

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In the one that came to me, with what I think is failure of the VGRS actuator (yet to be confirmed). I unplugged the actuator on a second test drive. Which made no difference, in the steering issue (violent-jerking to right) it is having.


From what I've read: "The actuator includes a brushless DC electric motor and a reduction gear mechanism that controls the speed of the steering rack" . This motor is locked, until power is added to it. So if disconnected my understanding is; It should lock to have normal HWY control, just like the LC steering. But steering at low speed would be hard, possibly harder than and LC IDK!
I had a 2005 LX470 with stock size tires and VGRS light on, steering at low speed was not hard, felt the same as LC. No weird behavior. I don't know the condition of the actuator.
 
I had a 2005 LX470 with stock size tires and VGRS light on, steering at low speed was not hard, felt the same as LC. No weird behavior. I don't know the condition of the actuator.
Which R&P LX VGRS or LC non VGRS?

I too have an 03LX which had VGRS light on, after snap ring recall service. Which would not correct by normal driving or clearing DTC. Nor just calibrating steering in tech stream. I had to do a full system re-calibration, including zero point. VGRS light now off, and does illuminate during key ON selftest. But does not come back on, after battery disconnect, which it should. I"ll be digging in to it as well, when time allows. I also have 2 07LX I can disconnect Actuator, and see how steering feels. Again, as time allows.
 
Here we see instances where we do not get DTC. Overheating of actuator motor is very interesting, since this shut down system into fail-safe. In fail safe steering would be harder.
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Father in laws 06 steering wheel decided to clock itself 20 degrees left one day out of the blue. reset it with tech stream and it's been fine for a few years now.

No idea which rack but it is oem.
 
I had never notice a difference in slow speed steering between LX & LC, until now!

As a test, I'll be unplugging my VGRS actuator in my LX's, as mentioned earlier.

I do anticipate it will take additional time to re-calibrate, once plugged back in.
 
If anyone has any info like diagrams, technically data, etc. On the NON VGRS and VGRS rack & pinions, please post here and or links too the info.

Looking to determine, if any difference in gearing and or pressure of these two Rack & Pinions?

Why:
One reason is to see if "perhaps"! The non VGRS R&P, is taking more pressure/lbs per inch to turn at low speeds than a VGRS R&P. If so, this may result in increase heat build-up in actuator. Which perhaps would shut down/place in fail safe the actuator, without DTC or lights.
 
If anyone in or will be coming to Denver area, that has an old VGRS R&P lying around. I could use it?

Once I have one, I could disassemble it and compare to non.
 
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1st:
Any strange steering issue?
One in which steering suddenly has mind of it's own. Steering suddenly pulls to one side by itself, then releases and repeats. The feel may be very sever veering vehicle direction, or just barely noticeable. Or may just feel a looseness between steering wheel and wheels, on occasion. Anyone with 03-07 LX470, experience this or any other steering issues.


None at all, steering has been perfect and predictable on this vehicle from day 1.
Sometimes, when parking and using the wheel a bunch (back and forth to both ends multiple times) my wheel will be off center straight for a few seconds.


2nd:
Has your steering rack & pinion been replaced. If so with which rack & pinion?
We've multiple Rack & Pinion (R&P) selections:
OEM LX VGRS R&P, which has a black stripe painted on passage side (RH side). Pricey!
OEM LC (non VGRS) R&P, which has a green stripe painted on passage side (RH side). Saves a few Dollars.
OEM re-manufactured, which likely is paint black all over, so indefinite paint stripe covered up. Budged friendly.
After-Market R&P, not likely VGRS. Low cost alternative.


Never replaced by me, nor according to any documentation available from LexusOwners

3rd:
Does your steering feel harder than normal to turn, at lower speeds?

Please listing your configuration, which will be very helpful and will be asked if not.
i.e. Pure stock or built and with what toys.

Also please note if your VGRS snap ring recall service has or has not been done.


I don't believe so, it behaves like any other vehicle I'd ever driven.
Stock until recently, I've replaced control arms and most bushings in the front end slowly. I have 275k. Larger than stock tires. Maintained by me since 214k.
Regarding recall, I believe that was performed since this was maintained by Lexus until I received it. Can't find any specific documentation/
 
@2001LC and others...I have my original 06 VGRS rack from my LX sitting here collecting rain, dirt and dust. I installed a new OEM Lexus VGRS rack a few months ago.

If anyone wants it for this experiment it's available.
 
@2001LC and others...I have my original 06 VGRS rack from my LX sitting here collecting rain, dirt and dust. I installed a new OEM Lexus VGRS rack a few months ago.

If anyone wants it for this experiment it's available.
I am interested in your old VGRS rack. Do you have any plans to come to Colorado this year?
 
Here we see instances where we do not get DTC. Overheating of actuator motor is very interesting, since this shut down system into fail-safe. In fail safe steering would be harder.

Does the VGRS motor act as a force contributor or simply a ratio multiplier? My understanding is the latter; assist is via the hydraulic pump and wheel:rack ratio by the VGRS. If this is the case, then a disabled VGRS motor (one that doesn't amplify steering inputs at low speed) should result in easier (lower effort) low speed steering as road wheel angle isn't being amplified by VGRS.

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Does the VGRS motor act as a force contributor or simply a ratio multiplier? My understanding is the latter; assist is via the hydraulic pump and wheel:rack ratio by the VGRS. If this is the case, then a disabled VGRS motor (one that doesn't amplify steering inputs at low speed) should result in easier (lower effort) low speed steering as road wheel angle isn't being amplified by VGRS.

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Sorry perhaps I need more coffee this morning. But I'm unclear on what you're saying:

"assist is via the hydraulic pump and wheel:rack ratio by the VGRS"?

"a disabled VGRS motor (one that doesn't amplify steering inputs at low speed) should result in easier (lower effort) low speed steering as road wheel angle isn't being amplified by VGRS." The Lexus VGRS while active, makes steering easier. So why would the system while off or in fail-safe result in steering easier?
 
The way I read it, the VGRS actuator does nothing to contribute to steering force. It only changes the ratio between the steering wheel and the rack. The hydraulic pump feeding the rack is where all of the assist comes from.

A functional VRGS increases rack movement at slow speed. At slow speeds, for every degree of steering wheel turn the road wheels turn a greater degree (vs non VRGS). So there is decreased leverage between the steering wheel and the rack. The decreased leverage should result in an increase in effort when VGRS is engaged. That is if the hydraulics can't keep up such as with a non-standard LC rack, oversized tires, etc.

VGRS doesn't make steering easier (less effort), it makes steering faster. The hydraulics are what reduces the effort.

So in the case of a failed VGRS, there would be no increase in slow speed steering and the ratio should stay static. Which is why I'm questioning the statement that a failed VGRS would result in increased steering effort.
 
The way I read it, the VGRS actuator does nothing to contribute to steering force. It only changes the ratio between the steering wheel and the rack. The hydraulic pump feeding the rack is where all of the assist comes from.

A functional VRGS increases rack movement at slow speed. At slow speeds, for every degree of steering wheel turn the road wheels turn a greater degree (vs non VRGS). So there is decreased leverage between the steering wheel and the rack. The decreased leverage should result in an increase in effort when VGRS is engaged. That is if the hydraulics can't keep up such as with a non-standard LC rack, oversized tires, etc.

VGRS doesn't make steering easier (less effort), it makes steering faster. The hydraulics are what reduces the effort.

So in the case of a failed VGRS, there would be no increase in slow speed steering and the ratio should stay static. Which is why I'm questioning the statement that a failed VGRS would result in increased steering effort.
Well written and a good point!

Perhaps I misreading the sells literature statement: "VGRS changes the gear ratio – not just the amount of power assistance – to an optimal level for all conditions."
 
this seems to be the most recent VGRS thread. I'm looking at my first 100 series and one thing that has kept me from looking at some 03-05 LX is VGRS. I've seen two now that were non functional, with the usual assortment of VGRS/VSC lights.

If one were to decide they didn't care for VGRS, does disabling it also disable VSC/ATRAC? I know the lights are all typically on together, but it seems that loosing VSC and ATRAC would diminish the capabilities of the truck offroad.

These parts are getting sparse and expensive so am curious if I am justified in avoiding these VGRS trucks? I just haven't seen a definitive "yes you can disconnect the VGRS computer AND retain VSC/ATRAC."
 
I’d suggest reading the codes, before you make assumptions about dash lights. VSC/ATRAC light up on just about anything.
 
I’d suggest reading the codes, before you make assumptions about dash lights. VSC/ATRAC light up on just about anything.
Yeah specifically both these trucks had the VGRS light and off center steering wheels. One had a service entry from Lexus a number of years back about needing a new motor but declined repair.

My question above still stands.
 
Yeah specifically both these trucks had the VGRS light and off center steering wheels. One had a service entry from Lexus a number of years back about needing a new motor but declined repair.

My question above still stands.

The question is “is VSC/ATRAC really disabled, every time those lights are lit?”.

If one were to decide they didn't care for VGRS, does disabling it also disable VSC/ATRAC? I know the lights are all typically on together, but it seems that loosing VSC and ATRAC would diminish the capabilities of the truck offroad.

It would depend on how you mean to disable it. I’ve seen posts about disconnecting the VGRS computer, that put the actuator in “fail safe”, and reportedly “everything was peachy”. I’ve seen other posts about disconnecting the VGRS computer “that didn’t fix a darn thing”. I’ve seen posts of people just driving it with VGRS “lit” in “fail safe”. If I ever reached the point that I wasn’t going to repair a faulty VGRS system, I’d be looking for a non-VGRS steering column.

VSC isn’t going to do much for you offroad, unless your idea of off-road is high speed dirt/gravel. ATRAC is useful at lower speed offroad.


These parts are getting sparse and expensive so am curious if I am justified in avoiding these VGRS trucks? I just haven't seen a definitive "yes you can disconnect the VGRS computer AND retain VSC/ATRAC."

If one were motivated enough, one could probably swap in a non-VGRS steering column. I’ve seen posts of “I’m going to do this”, but don’t recall anyone post that they had in fact done it.
 

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