When I am on the highway using the adaptive cruise control the car will stay in lane and speed up or slow down or even stop depending on the vehicle in front of me. My question if I don't turn on the switch on the steering wheel will the car automatically stop if the car in front of me stops and I don't brake?

 

Yes and no. The forward collision warning and avoidance will kick in and automatic emergency braking will attempt to bring the car to a complete stop before crashing into the car in front of you, but that cannot be guaranteed. You can't outrun physics, so if there isn't enough room for it to bring the car to a complete stop, it will at least slow it down to the point where the level of damage and injury is reduced, but not completely eliminated. It's a last resort. Not something to rely on.

 

Thank you. If I was stopped at a light and took my foot off the brake, I would roll into the car in front of me. Not that I want to try it. Correct?

 

yes and no. If you give the brake peddle a quick pulse after you come to a stop the auto hold feature will activate. That feature will apply the brakes and hold the vehicle in place until you press the accelerator; at which time it will release the brakes.

 

That's a little unclear to me, but I assume you meant you didn't change any switches on the steering wheel.

As I understand the question, it's: Will the adaptive cruise control come to a full stop without intervention or touching the brake?

@superswiss is correct about the emergency braking system trying to stop you, whether you have adaptive cruise engaged or not.

But in a non-emergency situation, the adaptive cruise control will also slow you all the way to a full stop, and sometimes do it very aggressively if the traffic suddenly slows.

The adaptive cruise will come to a full stop and wait for several seconds. Then it will resume following the car in front. If you have it enabled in your menu
HOWEVER, if you do touch the brake, you will disengage the cruise and you'll have to start moving yourself, by pressing the accelerator and then the resume switch on the steering wheel.

@TexAg91 is talking about the Hold function, which stops the car until you press the throttle.
Then, if you have pressed the brake and engaged the Hold, you've also disengaged the cruise control.

Hope I didn't muddy the water too much.

 

Thank you for all your replies. Maybe I wasn’t clear. Assuming hold is not engaged , and cruise control is not on. Local city driving. I just slowed down because the light turned red. Now I’m doing 3mph , will the car automatically stop or roll into the car in front of me.

 

@F18BEN This is what will happen.

 

But what if the adaptive CC is not on? City driving.

 

Good question. Rear cross traffic alert does stop the car when it is in reverse. (obviously adaptive CC is off at this time).
Since your question did intrigue me if Front cross alert will do this when adaptive CC is off, I tested this by placing a plastic garbage can in front of the car.
Result: Took the foot of the brake, the front sensors did detected it with the usual audible and visible warnings but the car did NOT stop!

 

Autonomous braking only intervenes at 4 mph and above, so no.