budrichard

In my previous testing of ACC, I found that with ACC activated at minimum mph and follow distance, I could somewhat crawl along in traffic and let ACC brake and accelerate. Sometimes when ACC would brake the car to a full stop, ACC would require a brief touch on the accelerator pedal before the car would start moving.
Yesterday in Stop & Go traffic, I decided to see the effect of PAS at low speed with ACC not activated which from what I could determine was no effect, i.e no braking.
The manual says the PAS is active above about 20mph with or without ACC and indeed I have had the warning symbols light up and once I got the 'Brake Check' when I forgot to turn PAS OFF for the track.
But and this is my point, at low speeds PAS does not brake for collision avoidance nor give Warnings.-Richard

Jeffdehr

PAS functionality has never been clear to me.

I know that if ACC is on the car will automatically brake to a complete stop.

If ACC is not activated PAS will provide audio and visual warnings and boost the brake pressure. However, what I'm uncertain about is whether or not it will automatically brake the car when ACC is off.

I had PAS/ACC on my 991.1 and liked the ACC. My 991.2 is a MT so I don't have it anymore.

My findings were the same as budrichard

Anyone know for certain if PAS will automatically brake if ACC is off?

visitador

Unlike other manufacturers, PAS is basically a warning system. It will alert you if it senses that you are about to hit another car. It does boost the brake system but it won't brake for you. The driver is the ultimate decider of when to push the brake. It functions when you are not using ACC.

Only when you are using the ACC that the car will brake for you at the distance that you told it to separate from the other car. I have never experienced PAS intervene when I am on ACC because, I think, the distance that PAS intervenes is much closer than the minimal separation that ACC allows.

I believe that my explanation applies to all Porsches with ACC. PAS has not been devised to be automatic braking iin a close call situation. Your foot is still the final decider.

budrichard

I will have to conduct some testing below and above the 20mph figure given in the Owner's Manual.
Below 20 mph, I am fairly confident PAS will not brake nor does it provide Warnings.
Above 20 mph, I know PAS provides Warnings as I have seen a few and I did get the Brake Check described in the Owner's Manual when I forgot to turn ACC OFF on Track.
Going down to Corner 5 at Road America, I got a short sharp jolt. I knew I had forgotton to turn ACC OFF and had previously decided not to try to turn ACC OFF during the DE session, so for the rest of the session, I made sure I did not come up behind anyone.
-Richard