Snow Button Question

[dspcap]

I have a 2008 Highlander and I am trying to figure out how the Snow button works and when you should use it. The manual sucks in explaining how it works. From reading several previous posts, it sounds like it basically starts the car in second gear... is that all it does? If so, then why wouldn't you just put the car in second gear and drive? Also, does it keep it in second gear until you disable it then (while driving)?

[Andrew Liu]

If it's auto, and you put the gear lever in 2, it will only enable the first two gears. It would still start in first, then shift to second, which is the highest it will go.

Snow would start the car in second.

[nov0798]

NOt only does it start the car in a higher gear, it also changes the computer settings from my understanding. It doesnt let the engine rev as fast, and most likely pulls a bunch of power out of the engine to make it more docile. It also probably changes the shift points on the tranny, engine timing, etc, to make the power at the wheels more manageable.
This is just a guess as to what it does.

[dspcap]

Thanks for the quick reply. So then once you hit a faster speed, it's probably best to turn off the snow button?

If I put the sequential shift in 2nd, does it start in 1st like an automatic or start in 2nd?

So, benefits of sequential would be slowing down without braking, towing, and run at higher RPM in a lower gear? I don't really see it as a gas saver..

[summerwind]

Originally Posted by dspcap

Thanks for the quick reply. So then once you hit a faster speed, it's probably best to turn off the snow button?

I don't really see it as a gas saver..

1) You do not need to select 2nd gear. Leave it in Drive. You do not need to turn it off when you reach highway speed.

2) As mentioned the transmission starts in second and the power and shift patterns change so you do not lose traction by over accelerating on snow/ice

3) It is not meant to save gas. It is to help you in the snow/ice to prevent wheel spin and traction loss.

[luvx77x8o4]

i was in lake tahoe this weekend. i was coming down going around 30-40 mph, i had it in snow + DAC...on some really steep downgrades i felt DAC wasn't helping slow the car enough so i just put in in 3 also.

[summerwind]

Originally Posted by luvx77x8o4

i was in lake tahoe this weekend. i was coming down going around 30-40 mph, i had it in snow + DAC...on some really steep downgrades i felt DAC wasn't helping slow the car enough so i just put in in 3 also.

DAC will not engage above 15 MPH.
DAC was not functioning in the scenario you discribed

You have to be in 1st gear and slower than 16 MPH

The procedure calls for (not in the owners manual)
1) moving the gear shift over to S mode
2) DAC button is on
3) downshifting to 1st and reducing the speed to less than 16 MPH
4) Foot can not be on the brake or accelerator

[wwest]

Originally Posted by summerwind

DAC will not engage above 15 MPH.
DAC was not functioning in the scenario you discribed

You have to be in 1st gear and slower than 16 MPH

The procedure calls for (not in the owners manual)
1) moving the gear shift over to S mode
2) DAC button is on
3) downshifting to 1st and reducing the speed to less than 16 MPH
4) Foot can not be on the brake or accelerator

Caution...!!!

Your HL is FWD or primarily so, downshifting a FWD or F/awd(***) vehicle to use engine compression braking can/will often result in loss of control, almost INSTANT loss of control. The very best way to slow an automatic transmission vehicle, RWD or FWD, on a steep slippery downhill drive is to first shift the transaxle into neutral and then apply the rear implemented e-brake ever so lightly, very judiously. If you expect to encounter this situation fairly often I would even suggest disabling the e-brake latching mechanism.

*** The only vehicles with sideways mounted engines that deserves the F/AWD term (vs F/awd) are those equipped with the Honda/Acura SH-AWD system.

[summerwind]

Originally Posted by wwest

Caution...!!!

Your HL is FWD or primarily so, downshifting a FWD or F/awd(***) vehicle to use engine compression braking can/will often result in loss of control, almost INSTANT loss of control. The very best way to slow an automatic transmission vehicle, RWD or FWD, on a steep slippery downhill drive is to first shift the transaxle into neutral and then apply the rear implemented e-brake ever so lightly, very judiously. If you expect to encounter this situation fairly often I would even suggest disabling the e-brake latching mechanism.

*** The only vehicles with sideways mounted engines that deserves the F/AWD term (vs F/awd) are those equipped with the Honda/Acura SH-AWD system.

DAC is a variation on the ABS/VSC feature and uses the brakes not the engine to maintain control

The Downhill Assist Control generates four-wheel hydraulic pressure
when the downhill assist control switch is pressed and the accelerator and
brake pedals are not depressed in order to maintain a constant low vehicle
speed without causing the wheels to lock.

Agree before VSC and all of the other computer stuff the best way was to shift into neutral.
Learned that when I had a Jeep Grand Cherokee with full time four wheel drive.
I hit an icy spot going around a curve and I was doing donuts until I put it in neutral.
All of the wheels were turning at there own pace and around and around I went.

The computer stuff now days brakes each wheel based on the VSC logic.
The yaw and wheel sensors and VSC computer where not in our cars of old

[TrailDust]

Originally Posted by dspcap

I have a 2008 Highlander and I am trying to figure out how the Snow button works and when you should use it. The manual sucks in explaining how it works. From reading several previous posts, it sounds like it basically starts the car in second gear... is that all it does? If so, then why wouldn't you just put the car in second gear and drive? Also, does it keep it in second gear until you disable it then (while driving)?

You might also want to read through this relevant thread if you haven't already....

Performance in Snow

TrailDust

[PhotonDreams]

When I saw the "Snow Button" two theories immediately came to mind. So I pressed the snow button, looked outside and saw that it did not start to snow, so I dumped that idea and moved to the second theory. I figured it would help traction in the snow when starting. So off I go to a big parking lot with a lot of snow. Push the button and start out from a dead stop. Sure enough as I pressed the accelerator down it moved forward steadily. Most interesting was the fact that if you keep slowly pressing the accelerator further and further down the button limits the normal revving up of the engine. Brought it to a stop, disengaged the button and tried the same slowly pressing accelerator. If you try it you'll find the accelerator peddle now revs the engine and the wheels spin and usually break free and you lose traction. So it seems the snow button starts you in 2nd gear instead of first and controls the fuel to the engine to help you avoid putting too much power to the wheels when starting in the snow. Hope this helps and prevents anyone from taking their Highlander to the service department and telling them the snow button has failed to make it snow!

[Horsdoobers]

When I saw the "Snow Button" two theories immediately came to mind. So I pressed the snow button, looked outside and saw that it did not start to snow...

I waited for it to snow INSIDE the vehicle. It did not do that either.

I'm sure I made it snow somewhere though. People!!! Stop pressing your buttons.

[fongster]

What exactly does this button do when pushed other than make a dash light come on? The manual doesn't say much beyond using for slippery conditions like snow. Is it good for rain? Does using it affect MPG? Thanks.

[abimom]

I causes the transmission to lock out 1 st gear.
This way, as soon as you press the gas the vehicle is in second gear. Helps prevent tire spinning from a dead stop.

[summerwind]

From the Common Problems and Solutions sticky

http://mojavetrail.webng.com/DAC_Sno...plaination.pdf