Weird problem while stopped on ice!!

[Checkered Flag]

So my G37X had this major issue while stopped on ice. This car is a tank and can go in extreme snow so I was very confused Sunday.
While on an overpass my car was sliding off the road while at a full stop. I'm no novice but it was frightening. I waslike WTF??? Car was in Snow mode BTW!

So I figured out what it is/was. The car is fighting itself. Somehow the stupid brain of the car couldn't figure itself out. Just go into neutral when at stop on ice. No more problem.

I think this is a condition for many automatics. I'm surprised the fix is not widely publicized in owners manuals!!!

[Checkered Flag]

So here's what I think is happening....

the engine was ever so slightly pushing the car while stopped and somehow the ABS were clicking on and off. Is this a mechanical failure on my vehicle, or does everyones brakes work this way??

[370Z/28]

I wish they would quit trying to make cars drive themselves. Sometimes you just need a good human behind the wheel.

One time on ice my husband parked his car on a hill. Off, in Park and key out of the ignition. The car started sliding down the hill and he had absolutly no control over it. Thank God it hit a curb and stopped. It was that or a big ditch.

[joe603]

All bets are off when modern vehicles come into contact with abnormal conditions...luckily no damage to the car.

Stay safe my northern drivers!!!

[Checkered Flag]

Someone described problem as existing in between the two differentials. He said it's the back differential that's the inherent problem with back wheel dominant AWD's...when on ice.

[Kendahl]

One time on ice my husband parked his car on a hill. Off, in Park and key out of the ignition. The car started sliding down the hill and he had absolutly no control over it.

This will happen with any car if the force of gravity pulling the car down the hill exceeds the available traction. In mathematical terms, the grade exceeds the coefficient of friction between the tires and the icy road. I have had it happen with a car too old to have VDC, traction control or even ABS. All I could do was let it roll, so that I retained steering control, and wait until I reached the bottom of the hill.

The only real solution is to install modern winter tires. Blizzaks are the best known example, but cheaper alternatives will work. I don't drive my G37S coupe in ice and snow because I don't want it to rust out. For that weather, I have a 15 year old Subaru with all wheel drive. It has a set of steel wheels and off brand winter tires. The improvement over all season tires is astonishing. The winter tires make a bigger difference than does the all wheel drive.

[370Z/28]

Oh, here in Memphis we only get one or two wintery weather systems a year. It really isn't worth it. My car stays in the garage!!!

[AZhitman]

So here's what I think is happening....

the engine was ever so slightly pushing the car while stopped and somehow the ABS were clicking on and off. Is this a mechanical failure on my vehicle, or does everyones brakes work this way??

Makes sense, if you think about it.

You're in Drive, on ice. Let's assume zero friction (although we know it's more than that, but clearly not enough)... With normal friction between tires and road, the brakes easily nullify the minor amount of power being transmitted to the rear diff. However, in your case, the wheels are moving, so the car attempts to compensate (when it really doesn't need to).

I'd be curious if there was a slight crown to the road, or if it was perfectly flat. I'm betting the former, but if it's the latter, then something's weird. Then again, the car doesn't know it's perfectly still. It relies on the wheel sensors, not its position in relation to the ground.

Although, that might be cool, to have an optical sensor (think computer mouse) on the underside, to assess ACTUAL motion (unrelated to wheel speed).

[audtatious]

Hmmm....ABS going off and TC trying to gain traction (and whatever ATTESA was trying to compensate), even when going so slow. Quite an interesting set of circumstances.