I've had my 2011 TL with Tech package for a few days now. I've noticed that every time I turn the engine off with the push button, there is a short mechanical buzzing sound. It's difficult to describe the noise, it's not really buzzing per se and it doesn't sound like it's coming from the engine. It's more in the dash area.

I've only test drove a base model so I couldn't be sure if this is normal for the models with Tech package.

Do you get the same thing?

 

I have a noise similar to your description. If it's like mine, it is the steering column lock engaging.

We often don't notice these things when we drive the demo. We are focused on other things.

 

My 11 does the same thing. I've always assumed it was the steering wheel lock engaging.

 

I saw that small paragraph in the manual about how to unlock the steering wheel if it's locked but I didn't know it would lock itself every time you turn the engine off and that it would make a sound. Good to know it's normal.