Anti lock brake problem

czjohnson · 10-17-2007, 08:25 PM

On Monday morning on my way to work I had some scary moments with my 2005 Prius. It was lightly raining, drove the same route I take every morning to work. When I came to one set of lights, I started to brake and the anti-lock, skid control started up. Took me by surprise, but thought maybe the road was greasy from the light rain in that spot. Next set of lights, almost ran into the car in front of me before it came to a complete stop. Once again, the anti-lock, skid control took over. Next set of lights, I didn't stop unitl I was a full cars length into the intersection. YIKES!! I pulled it over and had it towed into the dealer. They checked everything out, took it for many test drives and they found nothing wrong. Needless to say I am a bit parinoid about driving now. I start braking way before I need to just to make sure everything will work right.
If this happens again, should I step on my emergency brake to stop the car? I sure don't want to hit anyone and the dealer couldn't find anything wrong (must all be in my head!). Anyone else have this problem?

Thanks!

qbee42 · 10-17-2007, 08:27 PM

Perhaps it's time for some new tires.

Tom

luckyboy · 10-18-2007, 01:14 AM

<div class='quotetop'>QUOTE(qbee42 @ Oct 17 2007, 07:27 PM) [snapback]527147[/snapback]</div>

Quote:

Perhaps it's time for some new tires.
[/b]

also if it was the first rain of the season it will lift up all the oil that has been on the road all summer, nothing will brake well on that...

David Beale · 10-18-2007, 12:02 PM

Did you go over some bumps when this happened? This has been known to trigger the system due to the wheel being in the air while going over the bumps. You loose all braking for a second or so. It's enough to panic anyone!

OakHill · 11-23-2007, 10:54 AM

<div class='quotetop'>QUOTE(czjohnson @ Oct 17 2007, 07:25 PM) [snapback]527145[/snapback]</div>

Quote:

On Monday morning on my way to work I had some scary moments with my 2005 Prius. It was lightly raining, drove the same route I take every morning to work. When I came to one set of lights, I started to brake and the anti-lock, skid control started up. Took me by surprise, but thought maybe the road was greasy from the light rain in that spot. Next set of lights, almost ran into the car in front of me before it came to a complete stop. Once again, the anti-lock, skid control took over. Next set of lights, I didn't stop unitl I was a full cars length into the intersection. YIKES!! I pulled it over and had it towed into the dealer. They checked everything out, took it for many test drives and they found nothing wrong. Needless to say I am a bit parinoid about driving now. I start braking way before I need to just to make sure everything will work right.
If this happens again, should I step on my emergency brake to stop the car? I sure don't want to hit anyone and the dealer couldn't find anything wrong (must all be in my head!). Anyone else have this problem?

Thanks!
[/b]

Just had the same problem with my Prius. Replaced tires this summer so that wasn't the problem. Went off a highway exit on a rainy day, braked lighly to go around a bend and completley lost control because of anti-skid - and ended up swerving into other lanes. Luckily wasn't hit by other cars. Had the car checked out and no problems spotted.

qbee42 · 11-25-2007, 06:32 PM

<div class='quotetop'>QUOTE(OakHill @ Nov 23 2007, 10:54 AM) [snapback]543207[/snapback]</div>

Quote:

Just had the same problem with my Prius. Replaced tires this summer so that wasn't the problem. Went off a highway exit on a rainy day, braked lighly to go around a bend and completley lost control because of anti-skid - and ended up swerving into other lanes. Luckily wasn't hit by other cars. Had the car checked out and no problems spotted.
[/b]

You won't loose control because of anti-skid; if anything, the VSC will keep you from going out of control. If you push your tires beyond the limits of physics you are going to go in a direction you never intended, even with VSC. The VSC will try to keep the car from spinning, and will attempt to make it go where you point the wheel, but there is only so much that can be done to overcome bad traction or overly aggressive maneuvering.

I don't know the condition of your tires and the road, or how you were driving, so I can't say for certain that VSC was blameless, but the odds favor that assessment. Other posters have had the same experience, where they feel that VSC did something that it shouldn't, when in fact there was a loss of control that would have been worse without VSC.

Tom

daniel · 11-25-2007, 06:42 PM

I agree with qbee that you will not lose control because of skid control (VSC - Vehicle Stability Control). Either the road conditions were too slippery even for VSC, or your VSC has become defective and failed to operate properly.

To czjohnson: If you are convinced that the road itself was not slippery enough to have caused this, then there's something wrong with your brakes. ABS will cause the brakes to pulse and add a little to your stopping distance, but properly-functioning ABS will not do what you described. Take it back to the dealership (or a different dealership) and insist that they drive the car to experience what is happening.

jayman · 11-25-2007, 07:07 PM

Something just does not add up in the usual way. Properly functioning ABS/VSC are very easy to live with, and any failure mode has the various warning icons on the screen and warning lamps on the dash

The only time ABS will increase stopping distances is on gravel roads and in deep snow. Especially on gravel, if you lock up the brakes, the tires dig in and you stop faster. On dry pavement, once the tires lock up, you lose steering and directional control.

Driving back from the hobby farm today, the roads were quite nasty thanks to the frozen slush. I had the Prius this time, with the studded Goodyear Nordic tires on. Tried some silly manuvers on the gravel side road leaving the hobby farm, and at no time felt the car was trying to take control from me

Actually, with the studded tires, I really couldn't get the car to do much of anything beyond normal behavior

I didn't go out last weekend, and drove around the FJ with the studless Toyo Open Country G-02 Plus winter tires. We had slick roads last Sunday too. In an empty parking lot I was able to get the VSC to chime in terror by getting up to 65 km/h, then violently taking the wheel to full lock left or right. Nothing dramatic, just a lot of buzzing from the brake boost pump as it pulsed one of the front wheels to keep the Cruiser on the intended path

With an FJ Cruiser, once you shift from 2WD to 4WD, you disable the VSC. I was then able to get some gentle spinouts on the parking lot, but the tires stick pretty good. They're not as grippy as good studded tires, but close enough and no noise.

I will admit the traction control especially behaves quite differently between the Prius and the FJ. The FJ allows gentle wheelspin, but if I stand on it, the brake will apply on the spinning tire, then engine output will decrease.

The VSC is more aggressive on the FJ than the Prius, probably because the FJ has a much greater chance of rollover. The ABS appears to work the same between the FJ and Prius

If your Prius is actiing like that, with good tires on, and the dealership can't duplicate the problem, there is something else going on. Is it the same stretch of road, perhaps an oily section?

brick · 11-25-2007, 08:49 PM

This thread doesn't make any sense, except for the experienced folks who have already said "this doesn't make any sense." I've had ABS activate, and I didn't have problems. I've driven in some really nasty weather (even last week) on the lousy stock tires and I didn't have any problems. I've had VSC kick in due to a skid and the car straightened up before I had time for corrective actions of my own. Generally speaking, if you go off the road while ABS is activated then you shouldn't have been doing whatever you did. The only faults I can think of that would cause this condition would render a car completely un-drivable.

dongwoo · 12-17-2007, 03:53 PM

Hi all...I had a similar experience about 3 times now during my 2 months so far of having my Prius 08.One instance for example - Dry day, no oil evident on the road, going less then 20MPH turning slightly into a right turn-out lane, and all of a sudden by VSC kicks in - and my car jerks a little to the left and right. Felt like I lost control when that thing kicked in. Not even sure why it did... totally unexpected. Felt like if that happened to me on a wet road or just a rainy day - I would have skid --- opposite of what its purpose!Strange.

11-25-2007, 06:42 PM	#7
daniel Cat Lovers Against the Bomb Join Date: Feb 2004 Location: Spokane, WA Posts: 11,278 My Car: 2004 Prius Model: Package: #6 Thanks: 59 Thanked 201 Times in 127 Posts Friends: 0	I agree with qbee that you will not lose control because of skid control (VSC - Vehicle Stability Control). Either the road conditions were too slippery even for VSC, or your VSC has become defective and failed to operate properly. To czjohnson: If you are convinced that the road itself was not slippery enough to have caused this, then there's something wrong with your brakes. ABS will cause the brakes to pulse and add a little to your stopping distance, but properly-functioning ABS will not do what you described. Take it back to the dealership (or a different dealership) and insist that they drive the car to experience what is happening. __________________ Daniel Primary car: 100% Electric 2003 Porsche 911 Carrera. Estimated range at 55 mph: 81 miles total or 64 miles to 80% discharge. Top speed 70 mph. Secondary car: Zap Xebra SD, also 100% electric. 1.9 cents per mile. Range: 40 miles total, or 32 miles to 80% discharge. Top speed 35 mph. Faster downhill. Both EVs use electrons generated from water power. Gas guzzler for when I have to travel farther than 60 miles: 2004 Prius. "If voting changed anything, they'd make it illegal." -- Emma Goldman "Anyone who has ever looked into the glazed eyes of a soldier dying on the battlefield will think long and hard before starting a war." -- Otto von Bismarck

11-25-2007, 07:07 PM	#8
jayman Senior Member Join Date: Oct 2004 Location: Winnipeg Manitoba Posts: 11,560 My Car: 2004 Prius Model: Package: B Thanks: 35 Thanked 185 Times in 168 Posts Friends: 12	Something just does not add up in the usual way. Properly functioning ABS/VSC are very easy to live with, and any failure mode has the various warning icons on the screen and warning lamps on the dash The only time ABS will increase stopping distances is on gravel roads and in deep snow. Especially on gravel, if you lock up the brakes, the tires dig in and you stop faster. On dry pavement, once the tires lock up, you lose steering and directional control. Driving back from the hobby farm today, the roads were quite nasty thanks to the frozen slush. I had the Prius this time, with the studded Goodyear Nordic tires on. Tried some silly manuvers on the gravel side road leaving the hobby farm, and at no time felt the car was trying to take control from me Actually, with the studded tires, I really couldn't get the car to do much of anything beyond normal behavior I didn't go out last weekend, and drove around the FJ with the studless Toyo Open Country G-02 Plus winter tires. We had slick roads last Sunday too. In an empty parking lot I was able to get the VSC to chime in terror by getting up to 65 km/h, then violently taking the wheel to full lock left or right. Nothing dramatic, just a lot of buzzing from the brake boost pump as it pulsed one of the front wheels to keep the Cruiser on the intended path With an FJ Cruiser, once you shift from 2WD to 4WD, you disable the VSC. I was then able to get some gentle spinouts on the parking lot, but the tires stick pretty good. They're not as grippy as good studded tires, but close enough and no noise. I will admit the traction control especially behaves quite differently between the Prius and the FJ. The FJ allows gentle wheelspin, but if I stand on it, the brake will apply on the spinning tire, then engine output will decrease. The VSC is more aggressive on the FJ than the Prius, probably because the FJ has a much greater chance of rollover. The ABS appears to work the same between the FJ and Prius If your Prius is actiing like that, with good tires on, and the dealership can't duplicate the problem, there is something else going on. Is it the same stretch of road, perhaps an oily section? __________________ 2007 Toyota FJ Cruiser 5AT "C", Sun Fusion

11-25-2007, 08:49 PM	#9
brick Senior Member Join Date: Dec 2006 Location: Columbia, SC Posts: 894 My Car: 2007 Prius Model: Package: #2 Thanks: 9 Thanked 21 Times in 15 Posts Friends: 0	This thread doesn't make any sense, except for the experienced folks who have already said "this doesn't make any sense." I've had ABS activate, and I didn't have problems. I've driven in some really nasty weather (even last week) on the lousy stock tires and I didn't have any problems. I've had VSC kick in due to a skid and the car straightened up before I had time for corrective actions of my own. Generally speaking, if you go off the road while ABS is activated then you shouldn't have been doing whatever you did. The only faults I can think of that would cause this condition would render a car completely un-drivable. __________________ Improvements: Analog Tach, ScanGauge II, RadioShack EV Button, Turn Signal DRLs, dogfriend Seat Mod, some bits of pipe insulation stuck in my grill, and whatever I'm forgetting. 53.4mpg @ 54,000mi

12-17-2007, 03:53 PM	#10
dongwoo Member Join Date: Oct 2007 Location: Silicon Valley, CA Posts: 30 My Car: 2008 Prius Model: Package: #5 Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	VSC is strange Hi all...I had a similar experience about 3 times now during my 2 months so far of having my Prius 08.One instance for example - Dry day, no oil evident on the road, going less then 20MPH turning slightly into a right turn-out lane, and all of a sudden by VSC kicks in - and my car jerks a little to the left and right. Felt like I lost control when that thing kicked in. Not even sure why it did... totally unexpected. Felt like if that happened to me on a wet road or just a rainy day - I would have skid --- opposite of what its purpose!Strange.

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10-17-2007, 08:25 PM	#1
czjohnson Join Date: Jul 2005 Location: Southeast Wisconsin Posts: 6 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	On Monday morning on my way to work I had some scary moments with my 2005 Prius. It was lightly raining, drove the same route I take every morning to work. When I came to one set of lights, I started to brake and the anti-lock, skid control started up. Took me by surprise, but thought maybe the road was greasy from the light rain in that spot. Next set of lights, almost ran into the car in front of me before it came to a complete stop. Once again, the anti-lock, skid control took over. Next set of lights, I didn't stop unitl I was a full cars length into the intersection. YIKES!! I pulled it over and had it towed into the dealer. They checked everything out, took it for many test drives and they found nothing wrong. Needless to say I am a bit parinoid about driving now. I start braking way before I need to just to make sure everything will work right. If this happens again, should I step on my emergency brake to stop the car? I sure don't want to hit anyone and the dealer couldn't find anything wrong (must all be in my head!). Anyone else have this problem? Thanks!

10-17-2007, 08:27 PM	#2
qbee42 Senior Member Join Date: Mar 2006 Location: Northern Michigan Posts: 10,470 My Car: 2006 Prius Model: Package: #7 Thanks: 94 Thanked 387 Times in 289 Posts Friends: 10	Perhaps it's time for some new tires. Tom

10-18-2007, 12:02 PM	#4
David Beale Senior Member Join Date: Jul 2006 Location: Edmonton Alberta Posts: 2,116 My Car: 2007 Prius Model: Package: B Thanks: 3 Thanked 77 Times in 58 Posts Friends: 0	Did you go over some bumps when this happened? This has been known to trigger the system due to the wheel being in the air while going over the bumps. You loose all braking for a second or so. It's enough to panic anyone!