Yellow exclamation point in brackets is on. Squiggly line below mark. What does this mean?

If it comes on while stopped it is most likely the Hill-Start Assist. This holds the friction brakes on for a couple of seconds on a hill to give you time to move your foot from brake pedal to accelerator. This is engaged by pressing the brake a little harder than normal.

If this indicator comes on while driving it indicates wheel slip.

 

Description makes it sound like the tire pressure indicator (the brackets and squiggly line is really the cross section of a tire w. the exclamation point inside). Don't have my manual handy, but I believe there's a TPMS reset button somewhere under the steering wheel (?)

If it's really the tire slip indicator (profile of a car above squiggly lines) and the car's not moving, you've engaged hill start assist (by pressing the foot brake to the floor after stopping). Just put it in Park (clears the indicator) and then back in Drive (should remain off).

Later happened to me a couple times and I was concerned before I remembered ... It's a "Feature." Ugh.

 

Is it this light? TPMS Light Confuses Drivers Study Says

If yes, it is TPMS. As for "right pressure". What pressure are the tires at when they're cold? And yes, you might need to reset the baseline per the other posts.

 

Yeah, these lights are getting confusing.

And, IMHO, the idea of using the TIRE SLIP INDICATOR (a warning indicator) to also tell you that hill stop assist is engaged (a feature ON indicator) just adds to the confusion.

It's just a bad UI design choice.

 

OP's profile says 2006 Prius. Hill start assist didn't exist in the 2nd gen (04-09 Prius) AFAIK. It's definitely not on the 06. My 06 Prius is the 2nd highest package so it has everything available except leather.

I'm pretty sure it was new feature that started w/the 3rd gen. I helped a friend shop for cars last year and she ended up buying a new '11 Prius. Her salesman didn't tell her about HSA. I walked her thru the steps to engage it so she knew how and what was going on if she engaged it.

 

Yeah ...

Yeah ... there was some confusion wrt which indicator the OP was describing, and since it was originally posted to the Prius v forum, HSA was suspect since one possibile interpretation was that it was the TIRE SLIP INDICATOR.
I think we're clear now. Thanks.

 

^^^
Yes, I reported the original post as being in the wrong area.

It seems there's been a wave again of people posting in the wrong area, usually the Prius v area, for some reason.