I knew I wasn't crazy Check out the prohibited temps for 4th through 6th gears for road testing! And coolant temp lock out for the clutch lock up.

 

Ah, makes more sense in the context of you being in Ontario... the only one it's ever cold enough to experience here is the 6th gear lockout (and even that's gone after 3-5 minutes of the car running)

 

^^ LOL.

From my post at #345, it would seem that SNOW mode is "dumb". All it does is drive the throttle plate motor and depends on VSC/TC. Which explains why you can kill yourself moving off at an intersection in wet snow and the effin VSC/TC just kills ALL power to the wheels leaving you stranded

That's why NORMAL mode can be better in snow conditions.

I'm gonna go out on a limb and say there is no AI-shift in SNOW mode since there is only programming for NORMAL and PWR.

 

Agreed on the snow mode. Completely useless in actual snow. Better for stop and go traffic conditions more than anything else.

 

Thanks. I was going to mention these updates to the 1990s transmission information I posted earlier, but you beat me to it.

The most important updates are:
- There is now a snow mode
- Electronic throttle control
- Torque converter lockup occurs in gears 4, 5 and 6, and from lower speeds for better fuel economy. Back in the 90s, the torque converter only locked up above 37mph.
- There are 6 gears (duh), and gears 4, 5 and 6 are now configured in such a way that allows engine braking in Drive. The old 4 speed transmission had engine braking in gears 3 and 4 in Drive.

The last two points together make the 2IS transmission feel noticeably different to old slush boxes. Before, because the torque converter would be unlocked more often you would have the classic slushbox feeling when you release the gas pedal and the revs would instantly just drop to idle. Downshifts would also be super smooth because there was no engine braking in gears 1 and 2 in Drive.

Actually you can still experience these things in the 2IS while it is warming up, because lockup is prevented until the coolant reaches 140F. So while it is warming up, if you release the gas pedal, the revs will just drop to idle.

Downshifts in gears 4, 5 and 6 will also feel noticeably more abrupt than cars from the 90s because of the engine braking through the planetary gears in those gears while in Drive.

 

Seriously? Last winter, we didn't have a ton of snow, but when we did, I made sure to go testing with different modes, traction control on/off and snow mode on/off... Granted, I have an IS300, but, there is a hill just before my house that without a running start, you cannot make it up without traction control and snow mode. If you get stopped in the middle of the hill, you might as well back down, without those two aids (yes, both of them). If you are using traction control combined with snow mode, you can stop mid hill, and the car will slowly accelerate up the hill...

This is with performance all season tires (Bridgestone RE960's) which are undoubtedly a great all season tire and contributed to the performance of the car in snow, however, when two buttons can change the car from not moving whatsoever, to successfully driving along, there is obviously a change. It's not all just traction control either, as there is a definite difference in snow performance with snow mode on, especially at low speeds where it is truly needed... Anything over 10 mph and it is useless, I agree...

 

YMMV. Personally, I couldn't get out of my driveway in snow mode. As soon as there was ANY slippage, it would completely shut down the power. The ONLY way I could get going was to turn off the traction control entirely and spin the tires until I had some momentum.

 

What tires? Weird how it was a completely different experience... mine purposely allowed the tires to spin, while making minute adjustments as the car accelerates...

 

In my particular example it's while making a turn and accelerating, so the nannies go mental thinking I'm in a slide or skidding and shuts down the drive to the rear wheels Your system is probably less aggressive, which is ideal for your situation. SNOW is nice if going straight and not accelerating quickly in the slushy stuff

Nothing to do with PWR or NORMAL transmission modes but thought I'd share some pics from the MR2 engine removal and the new one waiting to be built up for install

 

This is as much information as I could grab from the TIS Repair Manual. concerning the description of what makes the transmission tick.

 

So I got my FSMs yesterday....been reading some. I want to continue my investigation, but I think I've found somethings that will help, and somethings that will confuse (at least me). I'll try to post in the next few days.

 

I've found this thread extremely interesting and useful.
I've got a quick question on the "AI (Artificial Intelligence) - Shift Control" extract posted by Kurtz on 09-22-10

In the first sentence it says, "through the pattern select switch".
Is this the same switch as the "ECT PWR" rocker button on my MY11 IS250 F-Sport ?

Argento

 

Yes. 10 char

 

brociouz, thanks for that confirmation.

That makes it much easier, at least for me, to understand what is being said in Kurst's post on 09-22-10
https://www.clublexus.com/forums/5807368-post24.html

Silvex (I used the wrong Username last time)
BTW, what did you mean by "10 char" ? I don't get it ... ........

 

You must have at least 10 letters/char minimum in a post.