Lotus known Ice Mode ABS Brake Issue is Not Alone
Discussion
It seems as if automotive the world has had a gag in it's mouth untill now...... Toyota Motors the worlds largest automotive producer has acknolaged the issue of it's anti lock brakes not functioning as designed.
Now if Lotus would follow and take the same action to repare the faulty ABS system Lotus owners would not have to worry if they could stop when they need to..
Toyota recalls Priuses, other hybrids worldwide....
Now if Lotus would follow and take the same action to repare the faulty ABS system Lotus owners would not have to worry if they could stop when they need to..
Toyota recalls Priuses, other hybrids worldwide....
TIPPER said:
Why don't they just disable the damn thing and perhaps people would bother to learn how to drive properly (on the other hand......).
Must be better than the 2 channel VX220 ABS, get one front on some grit, mud etc and it lets the opposite side that was braking effectively go and the car goes rushing forward. I've just purchased an Exige ABS ECU as it should make it 4 channel so remove this problem and should in theory be better with 16" fronts.. but then the stock VX one was massively improved on 16"'s going on in place of the 17",.. oh well. Not had the new ECU reset yet so no ABS at all, to test I put a wheel on some mud, no ABS but none of the scare that the old ABS gave it just pulled up nicely only locking the one wheel.
No ABS is definately better than bad ABS.
Edited by Herman Toothrot on Tuesday 9th February 17:32
Monkey boy 1 said:
roninexige said:
I believe they're still working on it because what it does now is lock up without breaking......
We really must stop feeding the Trolls here.The problem is when one wheel senses a different speed while loosing contact on a rough road surface during braking, the system locks up giving you reduced braking and a hard peddle until you lift your foot and reapply braking pressure..
Here's the official Lotus response to the same exact problem.....
Now check this bulls
t out.... Here's the official Lotus explanation of this braking issue:
"The symptoms being described are a result of the Electronic Brake Distribution (EBD) system operating. This system is also referred to as Dynamic Rear Proportioning (DRP) and is, as the name implies an electronic system which, through the ABS control valve block restricts the line pressure to the rear brakes automatically to a pre-programmed algorithm. You can consider it as an electronically controlled proportioning valve which measures parameters like the rate of deceleration and rate of pedal application and uses this data to anticipate a rear wheel lock-up and then reduces the braking effort at the rear wheels as necessary. If the ABS system is left to do this, it can only react to a wheel as it starts to lock and therefore the car can already start to spin before the ABS can start to work. In extreme circumstances, if the driver brakes very suddenly the EBD system can lock off the pressure to the rear wheels completely; what pressure was at the rear brakes as the EBD system engaged remains there and the rear brakes are still working as a result, but further increases in pedal effort will not increase the braking at the rear of the car because the pressure to the rear brakes cannot increase. When this happens the brake pedal goes hard, as it is now pushing against the front callipers and a closed valve only, instead of against the front and rear callipers. The rear callipers are single piston and therefore quite flexible, so they are a major factor in making the brake pedal feel 'soft'. When the valve closes, the brake pedal pressure no longer flexes the rear callipers, hence the increase in pedal hardness. The front brakes are still working just as well as before the valve closed and will give more braking if the pedal effort is increased, while with the rear brakes working as hard as they can the braking is NOT affected. The problem is the driver feels like braking is reduced (even though it is not) because of the change in pedal feel. If the driver continues to push hard on the pedal, the car will continue to slow as fast as it possibly can in the circumstances. If he increases the pedal effort the front braking effort will increase and the rear effort will remain where it was. If he was to back off the pedal for a fraction of a second, the valve will reopen and the rear brakes will operate as normal again, with the pedal feel going back to normal.
In the case of releasing and re-engaging the pedal the car should not be able to slow any faster than it was with the system engaged unless either 1: the driver triggered the system in the first place by stamping on the pedal too fast or 2: the system triggered because a rear wheel was unloaded when the brakes were applied and would have locked up but is now fully loaded once again and able to sustain a greater braking torque. If the rate of deceleration does improve when the pedal is reapplied then it is telling the driver that he is over braking either in terms of the ultimate ability of the brakes (cause 1 above) or the track condition (cause 2 above) and needs to adjust his driving style to suit. If the system were not fitted or disabled and he continued to drive that way he would be in danger of spinning when applying the brakes.
The suggestion that the system is running out of vacuum is just plain wrong. The system carries an internal reservoir of vacuum sufficient for three full brake applications. As with every servo system ever fitted to a car there is a one way valve which prevents the vacuum being lost when the car is on boost. The only way this reserve can be depleted is if the driver is maintaining boost while applying full brakes, i.e.: left foot braking very badly. In this instance I would argue that depleting the vacuum is probably a good thing as it should provide him with a warning that he is doing something awful to the car and it may reduce the speed of impact when he finally hits something as the brakes fade to nothing!! In normal use the throttle is closed when the brakes are applied, there is therefore no boost and the vacuum is automatically replenished as it is used."
That's right girls don't stomp on the brakes to fast because you wanna have enough time to kiss your ass goodby.
Edited by roninexige on Tuesday 9th February 19:14
TIPPER said:
Why don't they just disable the damn thing and perhaps people would bother to learn how to drive properly (on the other hand......).
ABS on later Elises is pretty good actually(apart from the ice mode problem!!),cuts in quite late.Not sure how not having it makes you learn to drive properly
For us non driving Gods i'll take all the help I can get thanks
(I think a certain Mr Walsh recommends having ABS rather than not for road cars)
I just talked to a Toyota regional field rep friend of mine and he said the problem with the Toyota and Lotus ABS are the same minus the wheel regeneration mode shuting down for the Toyotas....
It seems that it has to do with the stiffer suspension of the new Prius, much like that of the Lotus, if a wheel loses contact while braking on rough road surfaces the ABS locks up.... In the Prius case when the ABS locks up it also turns off the regeneration mode giving the Prius a feeling of acceleration and no brakes.....
It seems that it has to do with the stiffer suspension of the new Prius, much like that of the Lotus, if a wheel loses contact while braking on rough road surfaces the ABS locks up.... In the Prius case when the ABS locks up it also turns off the regeneration mode giving the Prius a feeling of acceleration and no brakes.....
Frank - this issue's been around for ages. Those of us who owned VX220s knew damn well how bloody shoddy the first ABS units that Lotus strapped onto their chassis were... the 2-channel ABS on the VX220 was borderline lethal in certain situations.
Lotus upgraded this to a 4-channel unit for cars wearing their badge. The newer cars are even better. But with cars very light at the front, getting the balance right between 'ice mode' and 'unintentional ice mode' must be bloody difficult and certain road / track conditions can tie the computer in knots.
Is the ABS computer actually a Lotus part, anyway? Or it from someone else's parts bin? Honest question.
Lotus upgraded this to a 4-channel unit for cars wearing their badge. The newer cars are even better. But with cars very light at the front, getting the balance right between 'ice mode' and 'unintentional ice mode' must be bloody difficult and certain road / track conditions can tie the computer in knots.
Is the ABS computer actually a Lotus part, anyway? Or it from someone else's parts bin? Honest question.
cyberface said:
Frank - this issue's been around for ages. Those of us who owned VX220s knew damn well how bloody shoddy the first ABS units that Lotus strapped onto their chassis were... the 2-channel ABS on the VX220 was borderline lethal in certain situations.
Yep all it does is make noise!cyberface said:
Frank - this issue's been around for ages. Those of us who owned VX220s knew damn well how bloody shoddy the first ABS units that Lotus strapped onto their chassis were... the 2-channel ABS on the VX220 was borderline lethal in certain situations.
Lotus upgraded this to a 4-channel unit for cars wearing their badge. The newer cars are even better. But with cars very light at the front, getting the balance right between 'ice mode' and 'unintentional ice mode' must be bloody difficult and certain road / track conditions can tie the computer in knots.
Is the ABS computer actually a Lotus part, anyway? Or it from someone else's parts bin? Honest question.
It's also not a problem unique to Lotus. I know of somebody that had exactly the same problem with a certain German sportscar, heading into a corner at around a ton.....ABS is not failsafe. As Cyberface says certain conditions will confuse the living daylights out of computers.Lotus upgraded this to a 4-channel unit for cars wearing their badge. The newer cars are even better. But with cars very light at the front, getting the balance right between 'ice mode' and 'unintentional ice mode' must be bloody difficult and certain road / track conditions can tie the computer in knots.
Is the ABS computer actually a Lotus part, anyway? Or it from someone else's parts bin? Honest question.
roninexige said:
I just talked to a Toyota regional field rep friend of mine and he said the problem with the Toyota and Lotus ABS are the same minus the wheel regeneration mode shuting down for the Toyotas....
It seems that it has to do with the stiffer suspension of the new Prius, much like that of the Lotus, if a wheel loses contact while braking on rough road surfaces the ABS locks up.... In the Prius case when the ABS locks up it also turns off the regeneration mode giving the Prius a feeling of acceleration and no brakes.....
must say I have been laughing at this hysteria over the Prius ABS...It seems that it has to do with the stiffer suspension of the new Prius, much like that of the Lotus, if a wheel loses contact while braking on rough road surfaces the ABS locks up.... In the Prius case when the ABS locks up it also turns off the regeneration mode giving the Prius a feeling of acceleration and no brakes.....
used to have a Lexus RX400H, it did exactly the same thing if you caught the brakes just at the wrong time, was not really a big deal as it would self-recover in under a second, just made you jump if you had not experienced it before.
the other one with the Hybrids is when the regenerative braking drops out mid-braking, it can do this for several reasons, ABS just being one of them, the effect is you actually have to use the brakes, so push the pedal harder (in normal use, the brakes actually do sod all).
But is the problem the cars braking or the American legal system? In other words is the braking perfectly adequate for sensible road driving, and the real problem is a bunch of rapacious American lawyers who have scented a prey they can sue? After all, this is the land of the ambulance chaser.
The braking issue described is common to many cars using an ABS system and indeed it is an issue on BMW motorcycles too. Question is - are more people saved by ABS than crash because of it?
The braking issue described is common to many cars using an ABS system and indeed it is an issue on BMW motorcycles too. Question is - are more people saved by ABS than crash because of it?
roninexige said:
Phil Just let your flintstone toes drag through the corroded electrolysis holes in the floor, I hear those nails can use a trim.....
Maybe the engineers at Toyota can actually program a ABS system to work as they "have to get it right" with the world watching..
Don't dis the toes!! Maybe the engineers at Toyota can actually program a ABS system to work as they "have to get it right" with the world watching..
Anyway this is on the Europa
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