plowing through snow

Some body taught me how to disengage the abs system when driving on snow.This will prevent the front wheels from spinning on snow and supposedly provide safer driving. I haven't tried it, but here is the method and its reversible ;just switch the car off.
1-press power twice without brake
2-push gas fully twice
3-push brake fully
4-put gear on N
5-repeat step 2
6-put gear on P
7-push brake and start the engine.
I would like to hear if anyone had tried it.

 

Disabling traction control can help.

Some people's driveways are on an incline, that makes getting in and out difficult. If either tire free-spins, then the other tire will refuse to pull the vehicle.

Old Chevys can climb those driveways fine, along with 4X4s, etc. Many newer light-weight vehicles do not have enough weight on the tires to climb those kinds of driveways. So it is not uncommon to get a tow, or a push.

With a prius, it may help to disable the traction control, so you force the vehicle to apply torque to both tires at the same time, when climbing an icy incline.

 

Wouldn't disabling traction control increase wheel spin?

 

Most vehicles, including the Prius, have an "open differential", which basically means the torque applied to both tires is exactly the same. If one tire happens to be on ice, that limits the torque that can be applied to *both* tires.

The differential behaves exactly like the planetary gears in the PSD. The ICE can't apply torque to the drive wheels unless MG1 provides a torque to act against. Same thing for the differential and traction control. Applying the brake to the spinning wheel is analogous to applying torque to MG1, and allows the differential to send more torque to the tire with traction.

Disabling traction control and allowing the tire to spin will simply allow it to dig deeper into the snow. This will either allow it to reach pavement or a different layer of snow and that may provide more traction. If it doesn't you're still stuck, but now the spinning tire is buried in the snow.

 

Yes!

I'd like to see a video showing someone failing to get up something with the traction control turned on, and then successfully making it with TCS turned off. Perhaps there is some situation somewhere turning it off could be an advantage, but that situation has to be a very rare case.

You never hear people saying, "I have tried both TCS on and off, and do much better without it". Instead you hear "I learned from a friend that disabling TCS is way better because humans > computers".

 

Traction Control is supposedly better on 3rd gen, got a bad rap for shutting things down too pre-emptively on 2nd gen.

If you're losing traction and traction control is activating, it's too easy to make the leap of logic that traction control is what's causing the loss of traction.

Yeah an A/B test would be good. Or better yet, and A/B/C/D:

A: all season tires with traction control
B: all seasons tires with traction control disabled
C: snow tires with traction control
D: snow tires with traction control disabled

I'll stick with C.

 

I am not sure about if there were only ice under one tire.

I have had problems when the entire incline is a sheet of ice, with some random loose snow on top. One tire free-spinning, the other tire seems to get a little grip, but does not get enough torque to carry us up the incline.

I am hoping that next time, I will have this routine written and with me, to give it a try.

I agree that overall 'C' [Studded snow tires with traction control] would be the 'best' all around.

However the next time I can not get up an incline I want other options.

 

And option "B" would be a gong show, lol.

There's a good video of a 3rd gen Prius climbing a slippery driveway, some way down the page, titled "Gen III Prius Demonstrates TRAC On A Icy Driveway:", here:

Think Smart » Blog Archive » Does the Prius do Snow?

You can see "pulses" in the snow tracks, presumably from the system engaging/disengaging. Hard to tell, but paused near the end I think it's got snow tires, looks like a lot of siping.

 

I'll stick with option E: Shovel your driveway and throw sand down on any ice that remains. Of course, I live in MA where they put so much salt on the public roads that they're usually just wet, unless it's a really bad blizzard in which case the roads are impassible because of the cars that have already crashed.

 

The prius is the only car on the road with an undefeated traction control, (to much torque will fry the axle) and all other vehicles have defeat-able traction control so they can generate as much wheel spin as possible to get out of situations like thick snow, ice, steep short hills etc.
I prefer to run studded snow tires, safety at all times, just like moderation is good.

 

It's snowing in Portland and my wife doesn't want to take the Acura up the hill to OHSU where she lives during the week. Looks like I might get to test this out in the Prius when I take her to the apt.

 

Never been in snow before so I wouldn't know :O

 

With 8 inches of snow, I'd call in to my boss that I'm working from home until the street is plowed. The undocumented Prius "toboggan mode" is great fun until you come across another car or a stop light.

 

I've made extensive use of the TCS today as the Portland area got snow and then sleet and freezing rain. On the drive home I watched rear wheel drive vehicles such as pickup trucks and Jeeps zigzag around, unable to keep the rear end hooked up with the front. I found the traction control to be less aggressive than in my Acura, with more permitted wheel-spin.

I don't know if there is a way to disable TCS, so I didn't test the difference between assisted and non-assisted driving. I did have to take a running start from the bottom of my cul-de-sac to make it up my driveway into the garage. Failing to make it up requires me to ease off the brakes and steer around parked cars as it slides back down. I had to put the car into N because the front end was uncontrolled (spinning) in D even when the brakes were released as I slid backwards.

 

Well, yes and no.

Traction control is the computer trying to prevent wheel spin just as ABS helps prevent locking your wheels when braking.

The problem is that it comes at a cost. ABS operates all the time, so an ABS system doesn't let you apply 100% of the effective braking power (before wheel lock) before it kicks in. The system is designed to compensate for unskilled drivers, not skilled ones.

Traction control kicks in before you attain 100% effective propulsion (before wheel spin). A skilled driver can feather the throttle to get the most out of the wheels before it starts to spin. With traction control, you never get to 100%.

For the most part, both of these are an improvement, but there are times it's counterproductive. When my traction control kicks in (going up a slick driveway), it actually cuts power to both wheels to the point where I can't go up. The first wheel spinning directs more power to the other wheel...which then easily starts to spin...resulting in power to both being cut down...often just as I'm starting to make upward progress.

 

The Prii's TC shuts down forward momentum and power when a wheel starts slipping. This basically brings you to a dead stop on a slippery uphill. The Prius has to do this for a reason, and it's probably been detailed somewhere. If the drivetrain could take a potentially hard shunt of spin-to-power than Toyota wouldn't have designed the Prius's TC to act in this way. It would have designed it to act more like every other modern car (including other Toyotas) that "thinks" and "moves" power from wheel to wheel to find traction and keep you moving. Instead the Prius stops power to the wheels, period.

I say it over and over again but for folks in the snow belt, 4 good winter tires makes a MASSIVE difference in this car. Improved traction between tires and surface keeps the wheels from slipping in the first place and thus, keeps the TC from intervening and shutting you down. I'm on my 6th winter here in Vermont in a Prius and I very rarely see that TC light blinking with snow tires.

 

And if it's so bad that traction control AND snow tires aren't cutting it, either due to snow depth or ice build-up, take a snow day.

 

So then why does the Prius v have switched TC deactivate capability?

While it might seem possible TC could help prevent possible damage, I have yet to find official documentation verifying this. Traction Control is just what it says...and is an important safety feature in modern vehicles...however in the situations discussed...it disables the vehicle. I have "turned it off" for short periods as required and will do it again when needed...but I always reactivate when the crisis is clear. I think a little common sense goes a long way here.

 

I would think because they've made sure it's safe to do so, that it's disabled in a way that won't damage the transaxle?

If there's no button, just a procedure in the Repair Manual, surrounded with cautions that this should NOT be used when driving the car, I figure it's not worth finding out the hard way.

 

I am outa my depth though, comparing to Denver. We got our first bit of snow overnight, just a dusting.



Likely to be washed away by rain by tonight.