Yea, I know the sound you are talking about. I’d be interested in the answer also. Sort of like a high pitched “pew”?

 

Maybe electronic parking brake?

 

Yea it's the parking brake engaging.

 

Have you checked your owners manual?

 

Good Point. Page 210 - Parking Brake - Section 4-2. When the parking brake operates, a motor sound (whirring sound) may be heard. This does not indicate a malfunction.

Makes sense now that others say its the parking break engaging.

 

Yep, that'd be the auto electric parking brake. It took me by surprise at first, but with mine being a hybrid, there's a bunch of different noises to begin with. Till my mechanical mind kicked in and paid attention to it.

 

If you hold it down it will turn off that function. I don’t need my parking brake to set every time I place it in park personally

 

Hold what down?

 

my hybrid sounds like a spaceship when it shuts down. is that a hybrid only thing or a gas model thing to?

 

Yes there are electric actuated servo motors on each rear brake caliper. Toyota is very proud of these puppies at $810 apiece so another good reason as stated above to use only as required rather than add unnecessary cycles to the actuators and decrease MTBF.

 

Yeah, turn 'em off so they rust, seize and don't work when you need them. Good Idea.

 

They're sealed and designed to operate in snow, ice, road salt so cycling less shouldn't hurt. OBTW Toyota describes in the manual how to turn automatic mode off if desired.

 

So are brake calipers and wheel bearings.

 

Too bad this is not in the owner's manual.

 

Toyota 2022 Highlander HV Owner's Manual, Page 224.