Anyone know what these buttons do?

That is your Park On/Off button- it's odd, because when you put the car in PARK with the other button in front of that, it automatically sets the Parking Brake- you can see that on the dashboard.

 

I believe if you hold down the (P) you can disable the automatic parking brake. It’s just enabled by default.

 

You've had your car for so long but never used the parking brake? LOL

 

Not many people with automatic transmissions actually use the parking brake. Trips up my parents when I do it.

Regulations code likely require a parking brake control even if it automatically engages. There could also be there for the times you need to turn the brake off while in Park, or on while not in Park, like Neutral.

 

All components are explained in your owner's manual.

 

Always use the parking brake when you park anywhere that's not level. There's a little metal device, called a parking pawl, that's inside the automatic transmission that stops the car from moving when in park but it's not the strongest thing in the world and I've heard of them breaking which leads to them having to open up your transmission to replace it....not anything cheap.

https://streetsmarttransmission.com/transmission-parking-pawl/

 

Correct, the automatic-transmission parking pawl (P on the transmission) is not strong enough to hold the vehicle on a slope, and it will break if attempted.

 

What is Toyota’s Auto Hold and How Does It Work?

 

This brief video may be of some help in answering your question about those two buttons.

 

Past threads here, on older generation Prii, indicate that the Prius parking pawl is much more robust than that.

 

I use the Auto Hold more and more.... it's so nice not to have to press on the brake pedal at a stop light...

 

See Post #6...

 

I don't recall anyone using the parking brake of the rental while we were in San Francisco. No mishap there.

I only started using it because of the larger degree of motion in the Prius parking pawl.

First is auto brake hold for stops.
Second turns off the traction control, which could be useful to do when on snow and ice. In other cars, holding it down will also turn off the stability control.

 

Yep, I've owned and worked on vehicles since the late-70's and the Owner's Manual on my wife's 2017 Prius (our first Hybrid) was read cover-to-cover a number of times!

Also find a Toyota mechanic, Ahmed, on YouTube named "The Car Care Nut" and he has many videos on Toyota Hybrids that are excellent....from maintenance to issues with some models and even reviews on many vehicles.

 

Note that much of the discussion here about the parking brake vs. the parking pawl is a bit overwrought because the default setting for the parking brake is Automatic, meaning that the Parking brake is set when the car is put in Park and released when the vehicle is put into gear. Only when you change it to Manual mode do you need to worry about whether it is set when you set the gear to Park.

Details for the Parking Brake are discussed on pages 193-196 of the owner's manual. Details for Brake Holk start on page 196.

I urge Prius owners to download and store the manuals on their computer. Using the search function of your favorite PDF reader can often help you find answers quickly.

 

I have a 2009 and all this time I figured park was automatic. I only use the park button if the car is on and I don’t want to roll. I guess I need to find out about “auto hold”.

Do we no longer get a hard copy of the manual? It has saved me a few times while on the road. I don’t have a printer. : /

 

Autohold is used during a drive. Turn it on with the button, and then when you come to a stop, you can take your foot off the brake. Then the car will continue to apply the brakes until you push the accelerator. I remember Ford advertising it many moons ago. Guess it is filtering out to others now.