Jarhead

This is my first winter with my 2010 IS250, manual transmission/rear wheel drive.

I read the User's Manual on TRAC and VSC, and looked for but could not find any mention in the manual about ETCS (Electronic Throttle Control System).

I am confused about the difference between TRAC and VSC.

When I push the TRAC button, the Multi-Info Display shows <TRAC OFF>.

When I push and hold the TRAC button, the Multi-Info Display shows <TRAC OFF> and, inside the speedometer ring, I see the "slipping car" icon displayed (VSC, right?).

Clearly, the two are related, but precisely what each one does and when driving in snow, which would I want to use and when are not clear.

Under what conditions would I want to disengage TRAC? And under what conditions would I want to disengage TRAC and VSC?

Many thanks for any clarification.

08wis250

i wouldn't recommend turning off your trac control unless u know how to control your gas sometimes with it off and the road conditions are bad your car when just spin out randomly pretty scary also there's times when trac control is stupid and cuts the power to the wheels and times when it saves u so its really up to u

idoke1

iTrader: (5)

In the snow with those off? Thats crazy? Theres another switch next to those. It should read ect, normal, and snow. Theres your switch

Jarhead

While I do, sincerely, appreciate you both taking the time to answer, neither of you has answered the original question:

Under what conditions would I want to turn off TRAC, and under what conditions would I want to turn off both TRAC and VSC.

Lexus put that off button there for a reason: I am trying to understand what that reason is/under what conditions _would_ someone want to turn one or both off.

Many thanks.

jgr7

iTrader: (1)

If you get stuck and need to spin the wheels to gain momentum to get youself out, or going up a slick road that you need to spin to get traction. With those on sometimes you won't be able to move.

idoke1

iTrader: (5)

Sorry about that. I was reading your title in how to use it in snow and assume it was that. There are many reasons as to why some may want it completely disabled for the circumstance. For me, I disable it both so I can enjoy its true driving nature without the electronics messing with traction. Trac off (to me) with vsc on, allows the driver in control for a slight period of time until a certain speed as followed by vsc coming into play. For inexperienced users, I would suggest leaving both on.

laobo979

iTrader: (5)

Not crazy since you never driven it on snow to know. It's more helpful then anything and snow button does nothing to help you get out of snow situation. It's like hitting the power button your no getting any extra power cause it say power on it. When turning just trac off it will stay off on till you hit 30mph then it's back on. Only way to turn it completly off is to turn vsc off with it. You'll want to turn them off when there heavy snow, fresh icey snow, where your in a stop and go traffic in unplowed streets. Having them off will allow you to move better without power cutting off. You don't want to enter a intersection then have your power cut off from slipping and might get hit from on comming traffic. But you gonna need to feel comfy with your driving able to keep them off. I drive with them off anytime it snow.

daileycon

Good question Jarhead. I got my 2010 IS250, manual transmission/rear wheel drive a week ago and of course we get snow in NC 3 days later. I was trying to go up a hill with fresh snow and just spinning. I was all over that manual trying to figure out what the hell to do. I pressed the Snow button, no help. I hit the TRAC button, says TRAC OFF, no help. Ended up leaving my car and driving my sister in laws van home. I WAS A VAN MAN!
My display still says TRAC OFF and I moved the SNOW button back. What is it supposed to be for just normal daily driving?

Jarhead

Thank you. That's very clear and now I understand. Since you say "those" plural, you are advising me to turn off both TRAC and VSC under the conditions you describe.

What would be the results if you shut off just TRAC and not VSC?

Thanks

Jarhead

Now it's becoming clearer. If I may try your patience a bit further...

When you say <allow the driver in control for a slight period of time>, could I ask you to elaborate on that just a bit, please.

And I guess <until a certain speed as followed by VSC coming into play> means that with TRAC off, when you hit a certain speed, VSC automatically kicks in. Right/

Again, many thanks for you help.

Jarhead

For the record in my manual transmission 2010 Is250, there is no ECT switch. I saw a YouTube video on ECT/Lexus and I think the ECT button is only for automatic transmissions.

Jarhead

Your experience is _exactly_ what prompted me to begin this thread.

Toyotas are well engineered vehicles and those engineers put those buttons there for a reason. A reason I am trying to discern before I find myself in the fix in which you found yourself. We are getting a lot of snow in the DC area this year and I am pretty certain I'll hit some snow/ice covered hill somewhere along the line this winter.

I had two BMWs previous to this Lexus (and a FWD Mazdaspeed3) and I found that when I was slipping and sliding up snowy hills, It _seemed_ like I got better traction when I shut off their version of VSC.

Jarhead

OK. Another vote for turning them _both_ off when driving under snow & ice conditions. Very helpful.

Going by daileycon's post, however, it doesn't seem that he had much luck turning these both off on snowy/icy _hills_. Of course you have to know how much snow, was there ice, how steep was the hill and, perhaps _most_ important of all, what is the condition of his tires? I assume his tires are the original Bridgestone Potenzas and if there is a lot of mileage on the car he bought, they could be pretty worn down.

I lucked out finding a 2010 model with a manual transmission AND only 17,000 miles on the clock so my tires are in very good condition.

idoke1

iTrader: (5)

What I meant by driver in control is when its just the driver and gas pedal. No electronics trying to control the the rear wheels. And yes, when hitting a certain speed vsc comes into play with the trac off.

idoke1

iTrader: (5)

Sorry but I driven in the snow occasionally, just not with my is350. I use a 09 jeep wrangler 4x4 to commute when traveling around the tahoe resort. I just dont recommend any rwd vehicles to run into heavy snow in which if the weather should change, black ice can form. Especially without the proper tires/chains. And especially if you have little to no experience in those conditions.