Lex2000TL

I had to drive our new 08 RX350 AWD last night during an ice storm. So, to be safe, I fooled around with “ECT Snow” switch. The car handled icy road really well. I have to say that I wouldn’t notice that there is ice, if I would not know already (granted, car has brand new tires as well). However, what I notice is that activating “ECT Snow” mode and de-activating it does not change engine rpm for the same speed, but with “ECT Snow” mode gas pedal becomes stiff, and I almost felt as something grabbed and held the rear end of the car. Very strange feeling.
The questions to folks that really know the answer: What is exactly happening when you activate “ECT Snow” mode? Fuel cut-off? ABS or TC kicks in?
I did little sear andf ound nothing on it.

geko29

All it does is start you off in 2nd gear instead of first so the tires don't spin as easily. Your perception that the gas pedal is stiffer is likely due to the fact that you have to press it down farther than usual to accelerate at the same rate. But other than locking out 1st gear, that button does absolutely nothing. Which is not to say it isn't useful.

Lex2000TL

Are you sure that does nothing, but starts off 2nd gear? Sorry, but I’m not. I’m absolutely certain that gas pedal becomes stiffer and car behaves differently, as I tried that mode on/off last night several times while driving the car, and not from stop, but in motion and without changing car speed, no acceleration (almost none). Starting from stop light does not apply here.
I want to get in touch with Lexus asking for details.

salimshah

ECT - snow only affects the bearing off. As pointed out by geko29 it locks out 1st gear (thus preventing max torque to the driven wheels ... which would slip if the traction is poor).

Other observations/perceptions can be attributed to driving on snow and ice.


Mod can shed more light on this ... The answers you get to your posts here are not from Lexus ... Lexus may be a sponsor ?? So for that you have to reach the dealership or write to Lexus Corporate.

Members who post, give their most informed opinions, which can be flawed. You may get more "official sounding" response from sales/service-writer/techs at Lexus dealership but that can be flawed too. The handbook would be the most legally bounding official answer.


Salim

RXSF

omg the RX, i dont think i feel any difference. but on my IS, it definately takes more of a push to acelerate. in that car, when i push all the way down, it doesnt even rev up to redline.

i think (might be psychological) is that it primes the VSC and ABS to be more sensitive as well. iono

spwolf

cars that use drive by wire can be setup so snow mode takes a bit stronger push on the pedal to produce same results. Thats done so you wouldnt, by mistake, press pedal too hard which would cause car to spin due to icy surface.

Tom H

I haven't really looked onto the ETC Snow feature on my RX but on some other manufacturers cars it not only causes the locking out of 1st gear but also causes a controlled slip between the other gears to avoid sudden abrupt shifts, which could throw the car into a spin.

The G Man

geko29 is right, as far as I know, all it does is start out in 2nd instead of 1st. The GX has this mode too. Activating this switch will do nothing if you have already shift pass 2nd. It is only for starting from a stop.

magicman

I just bought a 2009 RX350.
The ECT snow feature seems to do more than just start out in a higher gear. At 40 mph I pressed the button and the following happened:

1. I felt sometjhing else engage and seem to grab the road better. It was very similar to what my wife describes as the "suction cups" feel of engaging the 4 X 4 of our previous XL7s and earlier Subarus which had 4 X 4 rather than AWD.

2. At 40 mph the tach stayed at the same RPM for both engaged or off settings of the ECT

3. The gas did need to be pressed more to maintain the 40 mph with the ECT engaged.

4. page 165 of the 2009 manual describes 2 buttons not found on the 2009 RX350, "trac"and "VSC". I think this may have been a carry over from the 2008 (?) manual (both buttons are on the 2008 Highlander which is the same chasis as the RX). The VSC I think is now built into the computer as the car sticker says it has it. My guess is that the "trac" feature has now been incorporated in the ECT snow setting somehow.

Does anyone know the definitive mechanical/transmission set up from experience to answer this?

ecount00

insert " and often uncontaminated by any facts, actual experience or research"

salimshah

I prefer

"the advice is worth the money that was paid to get it "

Although Lexus' motto is in pursuit of perfection, the members are mere humans.

Salim

Grumpa72

Of course, one has to take into account the placebo effect in situations like this. I know that my 2005 only starts out in second gear and have not noticed, nor looked for, a stiffer gas pedal. Since I am starting out in a worrisome weather situation, the last thing I want to do is honk down on the gas pedal to see if it is stiffer. Ok, caveats on the way - you get what you pay for, I don't have any technical data to prove this, buyer beware, your results may vary, caveat emptor, nursing mothers should not consume..., caution alcohol is bad for your health, and the surgeon general has decided that smoking may cause cancer! All that said, unless there is some other "do-hickey" hooked up to my ECT button, any perception of improved drivability on ice is merely just that.

Btw, after we major snow fall or ice storms here in Pittsburgh, my unscientific observation is that more SUVs, Jeeps, 4WD trucks etc are stuck after sliding off of the road than standard fwd cars. Why is that? I always assume that folks think that their 4WD/AWD vehicle does more than help you get going. Of course, an educated driver knows that this isn't true.

salimshah

It is all a matter of tire-road_surface (traction). With 4 wd one is counting on one or more tire to have traction. Once you get on a surface where all the wheels loose traction, then it does not matter if you have a 2wd or a 4wd.


Salim

The G Man

I drove the wife's RX yesterday, it does seem like the RX's snow mode does more than just starting out 2nd gear like the GX's. There seems to be a restriction in power somewhere. Either they cut power at the DBW computer or they have cut back on the gas pedal's sensitivity.

RXSF

this must have changed from the 330 to the 350. pushing the button in the 330 does absolutely nothing (except maybe the 2nd gear thing). you dont feel any difference in pedal stiffness or acceleration