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2007 T&C Touring
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Asking because I fixed mine earlier in the year and I've never driven on ice with it before. It keeps raining, freezing, thawing and refreezing here. Was driving on my way home slowing to a stop and my brake pedal started thumping and pulsing pretty hard for a few seconds. Went around the block and it did it again, assumed it was TC.

When that happens, do I maintain pressure on the pedal? Or do I let off a bit and let the ABS do its thing? Thanks.
 

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Drivin' Maniac
2002 Grand Caravan ES 3.8L
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do I maintain pressure on the pedal? Or do I let off a bit and let the ABS do its thing?
YES. ;)

The TRAC system will pulse the brakes, keeping the van going in your desired direction.

But, letting off on the throttle a bit will do the same thing...

+++++++++++

To clarify, ABS retains steering control when braking. TC when trying to accelerate.
 

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With traction control, a wheel will start to spin and the traction control light will appear on your dash. Brake is applied to that wheel
What you are describing sounds like your ABS kicking in, doing its job.
Do you have stability control?
Check your Owner's Manual for clarification/operation. You don't pump the brakes ever when using ABS. ABS can be disconnected (fuse).
 

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Drivin' Maniac
2002 Grand Caravan ES 3.8L
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You don't pump the brakes ever when using ABS.
Be aware that, if you PANIC and slam the brakes on so hard as to lock ALL the wheels up, ABS won't do anything for you!
🙄

Most folks' reaction when the ABS or TC kicks in and vibrates the pedal(s), is to let off on the brake or accelerator.

When ABS was first implemented, I remember reading that policemen needed 'training' on the effects of ABS engagement because of the above tendency.
 

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I use to think it was a warped rotor. :)
 
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Be aware that, if you PANIC and slam the brakes on so hard as to lock ALL the wheels up, ABS won't do anything for you!
🙄
I don’t think that’s true. The ABS worked normally on every car I’ve driven and tested the ABS by stomping on the pedal. I just tried that on ice on my 2005 and the ABS worked fine.
 

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Drivin' Maniac
2002 Grand Caravan ES 3.8L
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The ABS works by comparing the speed of each wheel.

If you lock ALL four, the wheel speeds are all the same. So, it doesn't (think) it needs to engage. :eek:

You were not stomping HARD ENOUGH to test that. :ROFLMAO:
 

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The ABS works by comparing the speed of each wheel.
If you lock ALL four, the wheel speeds are all the same. So, it doesn't (think) it needs to engage. :eek:
You were not stomping HARD ENOUGH to test that. :ROFLMAO:
From a 2997 DGC Owner's Manual:
Anti-Lock Brake System — If Equipped The Anti-Lock Brake System provides increased vehicle stability and brake performance under most braking conditions. The system automatically “pumps” the brakes during severe braking conditions to prevent wheel lock-up.
Pumping of the Anti-Lock Brakes will diminish their effectiveness and may lead to an accident. Pumping makes the stopping distance longer. Just press firmly on your brake pedal when you need to slow down or stop.
Firmly with a big boot, not high heels, is hard enough. :)
 
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The ABS works by comparing the speed of each wheel.

If you lock ALL four, the wheel speeds are all the same. So, it doesn't (think) it needs to engage. :eek:

You were not stomping HARD ENOUGH to test that. :ROFLMAO:
Naw…try it yourself. I used to test the ABS as part of pre-purchase inspections for prospective used-car buyers, and it works fine no matter how hard you stomp on the pedal. The 2005 FSM does say that ABS is disabled below 3-4 MPH, so they can lock up right before a stop.

It doesn’t compare wheel speeds between wheels, it senses impending lockup on each wheel and modulates brake pressure to each independently.
 

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That doesn't make sense. So why have rear wheel speed sensors if the ABS doesn't use speed sensors - - for the traction control to have a baseline value to know if a front wheel is spinning?

But that doesn't make sense either, because my AWD has rear wheel speed sensors and ABS, but NO traction control. That means, ABS uses the speed sensors.
 

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fix it if you can
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So why have rear wheel speed sensors if the ABS doesn't use speed sensors - - for the traction control to have a baseline value to know if a front wheel is spinning?
Under "normal" operation, rear sensors are there primarily for electronic brake proportioning - the system will decrease rear pressures to prevent wheel lock-up rather than modulate the rear lines. It will modulate all 4 when braking on slippery surface.

Full service manual for Teves Mark 20e:
 

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ABS and Traction Control use the same sensors but use the information in different ways. A scanner, capable of ABS scanning, will tell you which sensor is bad, the right front on my 2007 ended up needing a new sensor. Since the traction control light was on, I knew it was a front sensor. The scan tool said right front.
TRACTION CONTROL — IF EQUIPPED
This system monitors the amount of wheel spin of each of the driven wheels. If wheel spin is detected, brake pressure is applied to the slipping wheel(s) and engine power is reduced to provide enhanced acceleration and stability. A feature of the TCS system functions similar to a limited slip differential and controls the wheel spin across a driven axle. If one wheel on a driven axle is spinning faster than the other, the system will apply the brake of the spinning wheel. This will allow more engine torque to be applied to the wheel that is not spinning. The Traction Control System reduces wheel slip and maintains traction at the driving (front) wheels. The system reduces wheel slip by engaging the brake on the wheel that is losing traction (spinning). The system operates at speeds below 35 mph (56 km/h).
 

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That TC system doesn't sound like nearly as much of a hindrance as some others I have had to put up with.

My aunt used to lease Toyota Rav4s every three years. When the TC would kick in, it would kill all engine power, and render the vehicle nearly useless. And, one of them didn't have a switch to turn that crap off. Even with the AWD and new tires, I had that POS stuck in ~3 inches of snow, and it took me about 20 tries to make it go about 50 feet. Every time a wheel would slip even the slightest bit, it would just sit there going bwahhhh while refusing to move. :mad: I could have likely gotten out of that spot with my van with little trouble.

Ugh. I hate electronic nanny BS.
 

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TC applies the brakes so it can actually slow you down some in the process of going ahead. Also:
If your vehicle becomes stuck in mud, ice, or snow, turn the Traction Control System OFF before attempting to “rock” the vehicle free
From drivingfast.net (Did Sienile create this site? :))
Snow & ice driving myths
 

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Drivin' Maniac
2002 Grand Caravan ES 3.8L
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I know that on our Honda, the traction control needs to be switched off to prevent the brakes from being applied.

Haven't had a Toyota with TC yet, tho' the daughter's RAV had a button to lock the center differential...

TOPIC DRIFT ALERT, again... :rolleyes:
 

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Huh,, I don't know what to make of some of this recent info. Probably WAY too early for me, along with not enough coffee...
Regarding trac cntrl; "
TRACTION CONTROL — IF EQUIPPED
This system monitors the amount of wheel spin of each of the driven wheels. If wheel spin is detected, brake pressure is applied to the slipping wheel(s) and engine power is reduced to provide enhanced acceleration and stability. A feature of the TCS system functions similar to a limited slip differential and controls the wheel spin across a driven axle. If one wheel on a driven axle is spinning faster than the other, the system will apply the brake of the spinning wheel. This will allow more engine torque to be applied to the wheel that is not spinning. The Traction Control System reduces wheel slip and maintains traction at the driving (front) wheels. The system reduces wheel slip by engaging the brake on the wheel that is losing traction (spinning).
"

So our trac cntrl system works like the old timey "duck footed drivng" technique you'd use with your 4x4 to try and get unstuck? But that was only effective if you had LSD. Wouldn't work with an open diff, and I don't think our vans have limited slip. How does our trac cntrl (electronic) make our vans function like LSD (mechanical)?
AND! If trac cntrl works as LSD, WHY disengage when stuck? Me thinks someone is on Lsd...

"The system operates at speeds below 35 mph (56 km/h). "
trac cntrl works at speeds LESS than 35mph? That's odd. Everything (which isn't much) that I thought I knew, is that trac cntrl is an overall safety system for all general driving scenarios. Freeway speeds included, such as hydroplaning. Under 35mph seems wrong?

I recall using other brand vehicles with trac cntrl, and if you got stuck, you'd turn off TC, and could get moving again. Just as others have said here, engine power would be greatly reduced, and I'm now thinking the brakes were too heavily applied, cuz the vehicle wouldn't really move. Perhaps the algorithms used on our vans have been refined?

Just recently, I had the time, energy and opportunity to try something. We had quite a bit of snow, and I had about 30 feet,, 9 meters for our Northern brethren, of slightly uphill driveway.
The following was done in about 2 foot increments.
1st tried moving with trac cntrl on. Left wheel spun. ABS light came on, van shuddered and moved. Didn't really seem power was reduced.
2nd, turned off TC. Right wheel spun. Van moved. Power seemed about the same as above.
3rdly, scraped away snow about 1 foot long, with about 1 foot of unscraped, 3 times in front of front tires. Sections alternated, so that when one tire was on unscraped pavement, the other one would be on scraped pavement. Engaged TC and started moving. ABS light came on, van shuddered and one wheel would spin until getting to next section, then the other tire would spin.
4th. Repeated the same thing, only without TC. Only the right tire spun. Moved, but not near as well as having TC engaged

I am flomoxed, and my brain and fingers are shot from so much early morning engagement...
You people have now caused me to hafta take a nap...
 

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So our trac cntrl system works like the old timey "duck footed drivng" technique you'd use with your 4x4 to try and get unstuck? But that was only effective if you had LSD. Wouldn't work with an open diff, and I don't think our vans have limited slip. How does our trac cntrl (electronic) make our vans function like LSD (mechanical)?

"The system operates at speeds below 35 mph (56 km/h). "
trac cntrl works at speeds LESS than 35mph? That's odd.
If you’re talking about applying the brakes to get both wheels to spin, that was meant for open differentials, not limited-slip. Slowing down the spinning wheel sent torque to the opposite, non-spinning wheel. Sorta like limited-slip does.

Traction control on our vans is really rudimentary compared to some of the later stability augmentation systems. I don’t think you’d want it to act above 35 — it could cause unexpected steering inputs that would probably be pretty terrifying going fast.
 

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If it starts snowing, call the wife.
Tell her you are staying SAFE in the bar until it stops! 😇
Or do snow angels while waiting for her to rescue you.
 
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