View Poll Results: What would you do about this?
Live with it
8
40.00%
Contact NHTSA
6
30.00%
Sue
2
10.00%
Sell the car and never buy Lexus again
4
20.00%
Voters: 20. You may not vote on this poll
Lexus: How to Avoid Fixing Design Flaws
04-17-14, 05:11 PM
#1
Driver School Candidate
Thread Starter
Join Date: Apr 2014
Location: CA
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Lexus: How to Avoid Fixing Design Flaws
What's the best way to avoid fixing a design problem. Lexus seems to have found it! First, tell the customer a dealer must be able to reproduce the problem. You don't compensate the dealer, of course. So, take my 2012 Lexus LS460L, please! After it rained I was taking a right turn at about 10 mph. The road was just slightly slick so the front of the car slid a couple of inches and instantly the skid control turned the front wheels sharply to the left causing me to careen into the lane to my left. There was, fortunately, no car there and I regained control. Lexus want's a dealer to reproduce this before checking it out. Impossible without a test track. Then I found that facing downward on a steep hill the car would roll forward even when put into reverse. And fast too. This makes parking on a hill in San Francisco potentially quite dangerous. Freeman Lexus WAS able to reproduce this error but had no way to fix it. This is a design flaw. But Lexus has no design flaws, don't you know, so if the car is performing according to the way it was designed they also won't even try to fix it according to their West Coast Regional Manager. Now that's just perfect, Lexus. At least until the DOJ finds out.
04-17-14, 08:29 PM
#2
You have to determine if the stability control is performing to spec or not to spec. I'm confused as to how they reproduced it.
Presumably, if it is out of spec, meaning that other Lexus vehicles do not perform that way, then they should be given an opportunity to fix your car under warranty and if they can't fix it, even though you have had it beyond the 18 months for CA lemon law, I imagine Lexus corporate will step up and take care of things.
If ALL Lexus vehicles have the same problem, then NHTSA is the right place to go as well as Lexus corporate. Presumably, the algorithm for the stability control is better for 99.999% of situations and there is the right combination of factors that you have discovered that represent a test condition they did not consider. This is based upon the assumption that you can in fact reproduce the problem repeatedly.
Last, if your tires are worn out or there are suspension or rim mods, you may be out of luck.
Presumably, if it is out of spec, meaning that other Lexus vehicles do not perform that way, then they should be given an opportunity to fix your car under warranty and if they can't fix it, even though you have had it beyond the 18 months for CA lemon law, I imagine Lexus corporate will step up and take care of things.
If ALL Lexus vehicles have the same problem, then NHTSA is the right place to go as well as Lexus corporate. Presumably, the algorithm for the stability control is better for 99.999% of situations and there is the right combination of factors that you have discovered that represent a test condition they did not consider. This is based upon the assumption that you can in fact reproduce the problem repeatedly.
Last, if your tires are worn out or there are suspension or rim mods, you may be out of luck.
04-18-14, 08:25 AM
#4
Lexus Fanatic
04-18-14, 05:07 PM
#6
Driver School Candidate
Thread Starter
Join Date: Apr 2014
Location: CA
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
First, no, dealers do not have facilities to reproduce skids and no one did. Second, I doubt the issue is related to my vehicle alone or else computerized results would probably have caught the error. Third, I can only say with complete certainty the I did not and could not possibly turn the wheels of my car to the far left, while making a right turn, in a fraction of a second. If the skid control is not capable of doing this I have no idea what would however, it is clear that turning into a skid is the correct response of a skid control mechanism in a high speed skid. At 10 mph with slight slippage it is not.
As to the question my first post is negative my response is, wouldn't you be given these circumstances?
As to the question my first post is negative my response is, wouldn't you be given these circumstances?
Trending Topics
04-18-14, 08:32 PM
#8
The OP may have a point buried in that somewhat off-putting post. US market LS 460 brochures in 2007 and '14 mention stability control, abs, ebs and eps are "integrated" but don't go into more detail. Australian market '07 and '12 LS 460 press kit texts are still available and are really interesting at pressroom.com.au. Sorry, I don't know how to post a link.
I can't be sure that US and Australian cars have the same safety systems but I'll wager they do. Aussie cars do the following:
Understeer: "Steering torque assistance to curb excessive steering angle"
Oversteer: "Automatically regulates steering angle"
All asc situations: "assists steering torque"
If US cars use the same system then the OP seems to be describing a regulated counter steer in response to an oversteering condition. However, the OP describes the front tires slipping, which by itself is understeer. If US cars use the same system as Aussie cars and if the OP actually experienced understeer and if his car then did a regulated counter steer then there is a problem here. But, that's sure a lot of "ifs"!
As for the forward rolling pointed downhill in reverse… even more "ifs". Very low trans fluid level allowing the fluid pick-up to unport? Car forward roll speed allowed to get too high… above a certain speed it won't go into reverse. A detailed description of this problem would be interesting.
A few months ago I tried the stability system on my '07 LS just to see it work. On a freshly rained on, nice wide street with no traffic I started a left turn at maybe 20 mph and gave it a quick stab of throttle to get the tail end out. The tail slid out farther and faster than I thought it would. The stability control then began cycling brakes at different wheels and I seem to remember the steering wheel turning to the right harder and faster than I could turn it attempting to counter steer. The system worked very well. Didn't think much about it then but I'll try it again next rain fall to be sure.
I can't be sure that US and Australian cars have the same safety systems but I'll wager they do. Aussie cars do the following:
Understeer: "Steering torque assistance to curb excessive steering angle"
Oversteer: "Automatically regulates steering angle"
All asc situations: "assists steering torque"
If US cars use the same system then the OP seems to be describing a regulated counter steer in response to an oversteering condition. However, the OP describes the front tires slipping, which by itself is understeer. If US cars use the same system as Aussie cars and if the OP actually experienced understeer and if his car then did a regulated counter steer then there is a problem here. But, that's sure a lot of "ifs"!
As for the forward rolling pointed downhill in reverse… even more "ifs". Very low trans fluid level allowing the fluid pick-up to unport? Car forward roll speed allowed to get too high… above a certain speed it won't go into reverse. A detailed description of this problem would be interesting.
A few months ago I tried the stability system on my '07 LS just to see it work. On a freshly rained on, nice wide street with no traffic I started a left turn at maybe 20 mph and gave it a quick stab of throttle to get the tail end out. The tail slid out farther and faster than I thought it would. The stability control then began cycling brakes at different wheels and I seem to remember the steering wheel turning to the right harder and faster than I could turn it attempting to counter steer. The system worked very well. Didn't think much about it then but I'll try it again next rain fall to be sure.
04-18-14, 08:52 PM
#9
What the OP describes in his post is understeer (front of the car slid a couple of inches). The correct steering response to understeer is to turn the front wheels further into the directions of the steer. This is the opposite of the correct response to oversteer where you turn the wheel in the direction of the skid (and away from the direction of the turn). Did the steering wheel turn into the direction of the skid? It would have to for the wheels to turn in that direction.
04-18-14, 09:41 PM
#10
We're not blind Lexus fanatics -- Look at the JMcRaney wind fix thread. That's an example of identifying a design flaw... I'll be the first to say that it Lexus's Internet Sales approach is lightyears behind BMW.
But the Lexus VDIM is something that's actually pretty darn good for safety. In fact, people usually complain that you can't turn it completely off (if you wanted to push the car on a track).
------------
Anyway, VDIM only affects the VGRS by 3 degrees AT most:
http://www.toyota.com/esq/pdf/The%20...fety%20(2).pdf
The difference of "up to 3" degrees isn't explaining what you experienced.
Only two explanations
- your car is broken. At which point you have to replicate the scenario under controlled conditions. (and you deserve a new car)
- you were going faster than 10mph, and what you experienced was one of your tires losing traction and then regaining traction abruptly. You just have to look at any of the "drift fail" videos.
Lets just start with the basics. To confirm, you've got a 100% stock vehicle including suspension/rims and your tires are properly inflated and have appropriate tread? I'm assuming you're running stock tires also?
Can you take a picture of the intersection? No railroad tracks or metal grates that would change the traction of the tires?
Right now, you're not giving people here enough information to figure out if
a) you're the first person to identify a problem that affects all cars (i.e. something that'll lead to a major recall).
b) there is a unique factor to your car, the road you were on, or your driving that generate the event you described.
In either case, it makes sense to get to the bottom of it. In the first case, because it affects all of us. In the second case, because if you're doing something wrong and you don't know you're doing it incorrectly, that's dangerous...
Last edited by GXAlan; 04-18-14 at 09:47 PM.
04-18-14, 09:44 PM
#11
Vehicle Dynamics Integrated Management (VDIM)
Toyota’s state-of-the-art Vehicle Dynamics Integrated Management (VDIM) system
enhances performance, traction control, and vehicle stability.
With comprehensive status data provided by sensors throughout the vehicle, VDIM
integrates braking and active safety systems, such as:
1. Adaptive Variable Suspension (AVS),
2. Electronic Power Steering (EPS), and
3. Variable Gear Ratio Steering (VGRS) systems
By the application of simultaneous, integrated control of all the elements related to vehicle
movement, including the drive train, brakes and steering, VDIM not only improves braking
activation, stability and traction control systems, it is also able to further improve the overall
kinetic performance of the vehicle.
Variable Gear Ratio Steering (VGRS) and VDIM Co-operation
VGRS cooperates fully with the VDIM system in order to help ensure a rapid and appropriate
steering response under a variety of vehicle stability threshold conditions.
For example, on a road surface with differing degrees of grip on either side of the vehicle,
sudden braking will cause the vehicle to pull towards the side with the higher friction
coefficient. As well as improving the efficiency of the Electronically Controlled Brake (ECB)
systems, VDIM simultaneously activates the Electronic Power Steering (EPS) and VGRS
systems to automatically regulate the steering angle and counteract the disparate, left and
right-side braking forces, minimizing the driver steering input necessary to maintain straight
line braking.
Similarly, when differing degrees of road surface grip cause the vehicle to pull towards the
side of the lower friction coefficient under acceleration, VDIM automatically regulates the
steering angle to help maintain vehicle stability with minimum driver input.
In the case of oversteer, the VDIM system automatically activates a counter-steer function
within the EPS and VGRS systems which, operating in tandem with throttle and ECB system
control, helps the driver to control a skid. Under such conditions, the combined use of brake
and steering control reduces the deceleration inherent in traditional braking systems.
In moderate under-steer conditions, VDIM combines engine output and braking control to
automatically help stabilize the vehicle. In the case of excessive under-steer, an increase in
the steering gear ratio by the VGRS combined with the steering torque assistance of the
EPS, automatically helps limit excessive turning of the front wheels and, in conjunction with
the VDIM system’s engine output and brake controls, in order to increase vehicle stability.
In all the above cases, VDIM activated VGRS can provide up to 3 degrees of additional
steering input, effectively coaching the driver in the application of steering wheel input
appropriate to the situation and, thereby helping maintain vehicle stability. Moreover,
simultaneous VDIM control of the Adaptive Variable Suspension (AVS) system automatically
regulates the suspension’s shock absorber rates to both increase body control under
extreme conditions and reduce vehicle nose diving under emergency braking conditions
Toyota’s state-of-the-art Vehicle Dynamics Integrated Management (VDIM) system
enhances performance, traction control, and vehicle stability.
With comprehensive status data provided by sensors throughout the vehicle, VDIM
integrates braking and active safety systems, such as:
1. Adaptive Variable Suspension (AVS),
2. Electronic Power Steering (EPS), and
3. Variable Gear Ratio Steering (VGRS) systems
By the application of simultaneous, integrated control of all the elements related to vehicle
movement, including the drive train, brakes and steering, VDIM not only improves braking
activation, stability and traction control systems, it is also able to further improve the overall
kinetic performance of the vehicle.
Variable Gear Ratio Steering (VGRS) and VDIM Co-operation
VGRS cooperates fully with the VDIM system in order to help ensure a rapid and appropriate
steering response under a variety of vehicle stability threshold conditions.
For example, on a road surface with differing degrees of grip on either side of the vehicle,
sudden braking will cause the vehicle to pull towards the side with the higher friction
coefficient. As well as improving the efficiency of the Electronically Controlled Brake (ECB)
systems, VDIM simultaneously activates the Electronic Power Steering (EPS) and VGRS
systems to automatically regulate the steering angle and counteract the disparate, left and
right-side braking forces, minimizing the driver steering input necessary to maintain straight
line braking.
Similarly, when differing degrees of road surface grip cause the vehicle to pull towards the
side of the lower friction coefficient under acceleration, VDIM automatically regulates the
steering angle to help maintain vehicle stability with minimum driver input.
In the case of oversteer, the VDIM system automatically activates a counter-steer function
within the EPS and VGRS systems which, operating in tandem with throttle and ECB system
control, helps the driver to control a skid. Under such conditions, the combined use of brake
and steering control reduces the deceleration inherent in traditional braking systems.
In moderate under-steer conditions, VDIM combines engine output and braking control to
automatically help stabilize the vehicle. In the case of excessive under-steer, an increase in
the steering gear ratio by the VGRS combined with the steering torque assistance of the
EPS, automatically helps limit excessive turning of the front wheels and, in conjunction with
the VDIM system’s engine output and brake controls, in order to increase vehicle stability.
In all the above cases, VDIM activated VGRS can provide up to 3 degrees of additional
steering input, effectively coaching the driver in the application of steering wheel input
appropriate to the situation and, thereby helping maintain vehicle stability. Moreover,
simultaneous VDIM control of the Adaptive Variable Suspension (AVS) system automatically
regulates the suspension’s shock absorber rates to both increase body control under
extreme conditions and reduce vehicle nose diving under emergency braking conditions
04-20-14, 05:13 PM
#13
Driver School Candidate
Thread Starter
Join Date: Apr 2014
Location: CA
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
I truly appreciate all of those who have replied and tried to think out the issues that have occurred with my Lexus. It's much more than Lexus has done, and that's my problem. Let's suppose, for a moment, that I am mistaken and it was the rear end slippage that caused the skid. I can't rule that out given how suddenly the skid control reacted and the effort I had to exert to get the car back into my lane. But, whatever the cause, this is clearly very dangerous as I was not going very fast. Lexus should care enough about people that could be hurt to test this. As for the downhill roll: This occurs on a a 15-20% grade, or more. There are many of these in San Francisco. Now imagine someone, facing downhill just before an intersection who puts their car in reverse and then, as most people do when parallel parking, looks over his right shoulder to back into the space. The car suddenly rolls into the intersection where he is hit by a truck and killed. Is this entirely his fault or does Lexus take some blame for this, especially on a car in this price range? I take note that some people found the post a little shrill and can't deny the emotional reaction to these issues which comes from the frustration of trying to get them resolved. Shouldn't Lexus WANT to resolve them rather than facing another round of fines from the DOJ?
04-20-14, 09:04 PM
#14
Rookie
Join Date: Sep 2013
Location: AZ
Posts: 56
Likes: 0
Received 0 Likes
on
0 Posts
I truly appreciate all of those who have replied and tried to think out the issues that have occurred with my Lexus. It's much more than Lexus has done, and that's my problem. Let's suppose, for a moment, that I am mistaken and it was the rear end slippage that caused the skid. I can't rule that out given how suddenly the skid control reacted and the effort I had to exert to get the car back into my lane. But, whatever the cause, this is clearly very dangerous as I was not going very fast. Lexus should care enough about people that could be hurt to test this. As for the downhill roll: This occurs on a a 15-20% grade, or more. There are many of these in San Francisco. Now imagine someone, facing downhill just before an intersection who puts their car in reverse and then, as most people do when parallel parking, looks over his right shoulder to back into the space. The car suddenly rolls into the intersection where he is hit by a truck and killed. Is this entirely his fault or does Lexus take some blame for this, especially on a car in this price range? I take note that some people found the post a little shrill and can't deny the emotional reaction to these issues which comes from the frustration of trying to get them resolved. Shouldn't Lexus WANT to resolve them rather than facing another round of fines from the DOJ?
No car company can take every complaint as a design flaw, unless it sees a lot of the same issues. No car company is perfect, but Lexus tries as hard as it can to address any issues.
It's top ranking at JD Power surveys lead me to believe that owners of Lexus like their cars more than other brands since they have fewer issues with Lexus than other cars. Trust me, as a past BMW 750 owner, you do not know what having a car with issues means.
04-20-14, 10:42 PM
#15
SerenityNow, I understand this skidding event that occurred was upsetting to you, but I have to believe that you were better off with the car maintaining stability than to have none at all. I've been on this forum for over 7 years and I have never read of any of any LS owner having the car lose control by itself. I think it is premature to call this a design flaw.
What I would suggest is you take the car to an empty parking lot and replicate it yourself. Video tape the incident and post it here. If there is actually a design flaw shown, you will get plenty of support here.
As to the transmission, you may have a faulty transmission, not a design flaw. The dealer has a way to fix it, he has to replace it. The only thing I can tell you is no automatic transmission will hold a car still on a steep hill at idle speed, reverse or forward gear. There is a certain amount of slippage in the torque converter. That is why you you can remain at a full stop while the transmission is in gear. Otherwise as with a manual transmission the engine would stall.
Video your own skid test and let's see the design flaw. Then I'll vote in your poll.
What I would suggest is you take the car to an empty parking lot and replicate it yourself. Video tape the incident and post it here. If there is actually a design flaw shown, you will get plenty of support here.
As to the transmission, you may have a faulty transmission, not a design flaw. The dealer has a way to fix it, he has to replace it. The only thing I can tell you is no automatic transmission will hold a car still on a steep hill at idle speed, reverse or forward gear. There is a certain amount of slippage in the torque converter. That is why you you can remain at a full stop while the transmission is in gear. Otherwise as with a manual transmission the engine would stall.
Video your own skid test and let's see the design flaw. Then I'll vote in your poll.
