ABS / Traction Control / Snow+ice

Awk

So i got access to my folk's car for a week, and it snowed yesterday yay. Question though:

If the car detects a loss of traction, my brake locks up and i hear a disgustingly clinking noise happening from the brake area. This sucks because i sort of need to brake when this usually happens. I disabled the Traction Control and it stopped locking up my brake when the car detects traction loss (ice). Is it normal to disable traction control during icy conditions? I can stop so much better if i just control the brake, instead of the pedal going flat and hearing odd noises.

Gihgehls

Yes, it is common. My coworker has a Nissan GT-R and if you find yourself in mud and don't turn off the traction control, the wheels will not move at all. I know that is a bad example because it is an uncommon car, but traction control systems all have the same idea regardless of how they implement it.

Mmmm... Cocks...

Why would he find is GTR in mud D=

I always thought that sound was the brakes un..breaking because they've locked up. Or were going to anyhow. It stops the breaks so you stay in control of the vehicle, no?

Awk

All i know is it works terribly on extreme icy conditions. Ive disabled the traction control because i cant even pull into a parking spot without the traction thing disabling my brakes as im pulling in because of a bit of ice. Scary shit.

Casually Hardcore

First of all, not all traction control is the same.

The one in a Nissan GT-R is, almost literally, controlled using the most state of the art automotive engineering that Nissan have yet created for a production car. Most other traction control isn't no where near on par with the Nissan GT-R. That and the GT-R is mostly tuned for racing applications, not off roading o_O .

But the traction control disables your brake because it uses your brake to control the traction. If it sense one wheel slipping (by which I mean the tire haves no traction and is just spinning), it'll use the brakes in order to regain traction.

Awk

but my wheels arent spinning, theyre locked up (ice). if the wheels are locked, why would it use my brake to regain traction...

I thought it was the ABS maybe, but when i disabled the TC switch, it stopped screwing up my brakes when the tires locked up.

Casually Hardcore

If it's locking up, then ABS should be kicking in. What's the make and model of this car?

Awk

newer honda accord

Gihgehls

Awk wrote: »

but my wheels arent spinning, theyre locked up (ice). if the wheels are locked, why would it use my brake to regain traction...

I thought it was the ABS maybe, but when i disabled the TC switch, it stopped screwing up my brakes when the tires locked up.

Your wheels are locked because the ice really confuses the TC. The way TC on your car probably works is that when TC detects the wheel exceeding the limits of traction, it applies the brakes a little bit to slow the wheel down and let it adhere to the road again. When you're on ice, all bets are off and your tires are going to slip even at very low speeds. The TC doesn't know that you're on ice, it just knows the wheels are slipping, and it does its best to keep the tires at 100% traction. The side effect is that the tires never spin at all because any movement would make the wheels slip.

mts

thats not traction control. that is the abs kicking in assuming you jammed on teh breaks when the noise happened?


you might feel it, but you shouldn't hear the traction control turn on, its silent in the honda system

Gihgehls

Like I said in my first post, different traction control systems work in different ways, but they share the same goal: to control the speed of the wheels in spite of the driver's throttle inputs. It can do this in a variety of ways, from controlling the throttle or braking individual wheels. From wikipedia:

The intervention can consist of one or more of the following:

• Retard or suppress the spark to one or more cylinders
• Reduce fuel supply to one or more cylinders
• Brake one or more wheels
• Close the throttle, if the vehicle is fitted with drive by wire throttle.
• In turbo-charged vehicles, the boost control solenoid can be actuated to reduce boost and therefore engine power.

Typically, the traction control system shares the electro-hydraulic brake actuator (but does not use the conventional master cylinder and servo), and the wheel speed sensors with the anti-lock braking system.

EDIT: Systems that can brake individual wheels are cooler and safer than systems that try to control the throttle, because with the first type your left tires can be on the road and your right tires can be in snow or mud and when you jam the throttle down the car still goes straight.

Iceman.USAF

I believe the issue here is that traction control does not equal ABS. Traction control prevents you from doing stupid shit like flooring it in your 500 HP Mustang and careening off the road out of control.

ABS prevents your wheels from locking when you try to stop your 500 HP Mustang from careening off said road after flooring it, allowing you to properly decelerate and steer.

They work together, but are not the same. You need to "pump" your breaks a bit and not just step down. Lightly tap them to slow your car down. If that doesn't work....uh, I dunno really.

mts

youre not supposed to pump ABS breaks, that defeats the purpose of anit-lock

Iceman.USAF

....only if it works. If the wheels are locking, the ABS is not functioning properly.

Fats

I admit that most of my vehicles haven't had ABS, but it won't keep you from locking them up on ice, will it? The only system I heard about like that was on early 2000's BMW bikes, on which if you rode on gravel/dirt/other slippery shit and didn't turn the ABS off, you literally could not stop.

LaOs

Fats wrote: »

I admit that most of my vehicles haven't had ABS, but it won't keep you from locking them up on ice, will it? The only system I heard about like that was on early 2000's BMW bikes, on which if you rode on gravel/dirt/other slippery shit and didn't turn the ABS off, you literally could not stop.

That's exactly what ABS does.

Zeon

Fats wrote: »

I admit that most of my vehicles haven't had ABS, but it won't keep you from locking them up on ice, will it? The only system I heard about like that was on early 2000's BMW bikes, on which if you rode on gravel/dirt/other slippery shit and didn't turn the ABS off, you literally could not stop.

The problem youre thinking of with the BMW ABS systems was the fact that due to the way they routed the ABS stuff, the ABS module going out would take out your entire brake system, leaving you with absolutely no brakes at all.

ABS will keep you from locking your brakes up, its right in the name, Antilock Braking System. It does this by detecting abrupt wheel deceleration, and modulating the braking system (in effect, pumping the brakes similar to proper braking technique in a non-abs equipped car).

As for the traction control system in the OP's car, it sounds wrong that its actually leaving you with no brakes... Are you sure its not malfunctioning? Traction control systems in most consumer commuter cars are designed with exactly those kinds of driving conditions in mind, snow, ice, rain, etc. The fact that the car seems to respond less well would lead me to believe theres a problem, unless youre just not used to the traction control system.

The Black Hunter

The brakes are used to simulate the traction lost on the wheel, total traction loss = total brake

exmello

If you hear a grinding noise when you brake with ABS keep braking. The ABS is DOING ITS JOB. Then next time, stop earlier. Sure, you felt like omg I'm not stopping, fucking ABS, but without them it would take twice as long to stop and you would be dead.

RUNN1NGMAN

LaOs wrote: »

Fats wrote: »

I admit that most of my vehicles haven't had ABS, but it won't keep you from locking them up on ice, will it? The only system I heard about like that was on early 2000's BMW bikes, on which if you rode on gravel/dirt/other slippery shit and didn't turn the ABS off, you literally could not stop.

That's exactly what ABS does.

Even with ABS, you may not be able to stop on ice and the brakes may still lock up. ABS functions on the premise that there is some friction between the tires and the driving surface, meaning that stopping is theoretically possible. If there's close to zero friction, like you've got performance tires on your car and you're trying to drive across packed snow or a sheet of ice, there may be so little friction that even with the pulsing of the ABS the brakes will still lock up because that threshold is so low. In that case ABS isn't hurting, but it's not going to stop you from sliding out of control either.