Got my 2012 IS250 AWD over the summer, got about 5000km on it now. Its dead of winter up here in Canada right now and here is a weird problem I've noticed.

When driving, when I let my foot off the accelerator to coast, the RPM will dip so much that I can feel the car stutter a little, then the RPM will go back up and stablize while still coasting. Is that normal? Or is something wrong with my car? I've checked to see if the car was trying to downshift/upshift gears, but it wasn't. Is this a cold weather problem? Maybe I wasn't paying attention during the summer months, but this problem only seem to start when winter started.

Been driving for 15 years and haven't had this issue with an car I've driven before.

 

same here!!!!

 

Not just you. I've pretty much only had my car for the cold winter here in Omaha for a few weeks (-10 to 20 degrees on average) but mine does this as well. My '00 Corolla used to do this (not to imply this is a Toyota thing, completely different engine), and I had a Honda before and it never did this. Mine doesn't "stutter" though, the RPMs just dip quickly and come right back up.

By the way, '11 IS350 AWD.

 

Was there a fix for this issue? I have a '15 IS350 and have experienced something similar 2 or 3 times over the past 18 months.
The symptom is usually from a stop, I push the accelerator and there is nothing for a second, I see something flash on the dashboard but is
so quick I am not able to read it, then the engine kicks in and away I go. No check engine light or codes are posted.

 

Sorry wrong forum, will repost.

 

Traction control stabilizer cut off the engine. When you step on the gas, the tire slip cause traction control system cut off your engine to help the car going straight forward.

 

Just saw this thread. You car seems have same problem as mine. I also got a IS250 from 2012z
Here is my thread about the problem https://www.clublexus.com/forums/is-...ml#post9763300
Check out the video and see if that's the same behavior with your car.

 

It's been a few years since I've had the car. Like in above poster's post, it only happens when temperature is well below freezing. So I do suspect is something that needs to warm up before it'll function "normally". Definitely does not happen in the summer months, so it is temperature related.

 

I see this problem with a lot of people and came to the conclusion that it is just something the car does to warm up the engine and transmission quicker in colder temperatures. It will also tend to do it a lot lot more if you park your car outside in the cold, or if there is a huge temperature difference between your garage and outside. When it was close to 70 degrees (~21 C) outside it never did this. The minute the temperature dropped below 45 (~7 C) it started doing this. It stops doing it once the car is warm, so that is probably why.