I have a 2003 XC70. The car runs great. Except the idle at a stop is not as smooth as I think it should be. I can feel fibration on the steering wheel.

In the past year I have changed the engine mounts, had a tune up and a throttle body cleaning.

I did this all because the idle was not perfectly smooth when at a stop. After all was done summer came around. I though problem solved. The idle was pretty close to perfect.

I have noticed when it is real cold out (minus 15) a vibration can be felt on the steering wheel when at a stop. Same as it was before I had the above things done. Car runs great otherwise.

What sensor would affect the idle when its real cold out? If any.

I have not had the throttlebody changed.Dealer says this is the likely problem. I had it cleaned but no software update yet. The dealer tells me if I go for the software update and it does not solve the problem they will replace the throttle body under warranty. Does it sound like a thottlebody issue?

Anyone else have this problem or know what the fix is?

Jim