Bill Dearborn

HSA exists on all M7s. It doesn't make much sense on an automatic transmission where you don't have to worry about the car rolling backwards when you take your foot off the brake as you are letting out the clutch and trying to figure out how much throttle to use. That is one of the hardest things for people to master when they learn to drive a manual transmission car. With automatics it doesn't really matter all that much even if the car rolls back a little since the likelihood of stalling the car or tearing up the clutch is zero when the torque converter cushions the start as it overcomes the backward roll and moves the car forward.

From the 2015 OM.
Automatic EPB Release (Page 9-36 2015 OM)
The EPB will automatically release if the vehicle is running, placed into gear, and an attempt is made to drive away. Avoid rapid acceleration when the EPB is applied, to preserve parking brake lining life. The EPB can also be used to prevent roll back for vehicles with a manual transmission taking off on a hill. When no roll back is desired, an applied EPB will allow both feet to be used for the clutch and accelerator pedals in preparation for starting the vehicle moving in the intended direction. In this case, there is no need to push the switch to release the EPB.

Hill Start Assist (HSA) (Page 9-37 2015 OM)
If equipped, HSA may automatically activate when the vehicle is stopped on a grade. This feature is designed to prevent the vehicle from rolling, either forward or rearward, during vehicle drive off. During the transition from releasing the brake pedal to accelerating to drive off on a grade, HSA holds the braking pressure to prevent rolling. HSA will not activate if the vehicle is in a drive gear and facing downhill or if the vehicle is facing uphill and in R (Reverse).

HSA uses the ABS/TC/AH system to hold the car's brake system pressure. The EPB isn't used in this feature.

Bill

ronsc1985

The hold is only for a short time after you take your foot off the brake. I see this all the time on my driveway. If you don't almost immediately let out the clutch the car will roll backwards. With the automatic transmissions the hill holding stays on until you move forward.

ronsc1985

That's true until someone stops right on your back bumper and you roll back into him. That's why Mercedes, Lexus etc. have this in their cars.

madrob2020

In your quote from the OM, under HSA it states "if equipped". Secondly, it says "from releasing the brake pedal to accelerating..." which would only apply to how one manipulates the "two" pedals of an auto tranny vs the "three" in an manual. But, I'm sure you will opine/interpret it to suit your mechanical knowledge.

tzoid9

This is actually getting funny! I ordered my car from scratch, built it exactly the way I wanted it in January, 2016 and it arrived in late March, 2016. "Hill Assist" was standard issue with the Z06 built with an M7 transmission.....I didn't order it, it came with the M7 transmission selection. I also know that the Hill Assist feature is standard issue in a number of other new cars (non GM) equipped with manual transmissions. Now maybe it was an option in 2015 cars, I can't speak for them. I do agree with Bill, hill assist in an automatic transmission car would be a complete waste of money.
As far as the automatic emergency brake release, I must have a defective switch or an electronics issue with this feature. My car won't budge with the emergency brake on. I'm perfectly OK with that, but will likely have it checked next time I have the car serviced.
In closing, the thread that talked about setting the emergency brake when you come to a hill then either feathering the clutch and accelerating to release the E/B or releasing it with the switch, to me at least, that seems a little goofy! An E/B is designed freeze your car in that precise location when you set it, in most cases, to leave the car. Hill assist is an operating assist so when you are stopped on a hill, it keeps the brake on for something like 5 seconds after you take your foot off of the brake.....as Bill above indicated, syncing the accelerator with the clutch release. If in that 5 second time period you still can't move forward due to traffic (or whatever), you just depress the brake pedal again and it resets itself, for another 5 seconds when you take your foot off the brake.

Greg00Coupe

Dump ? You guys are pushing the button down to release the E Brake right? Not pulling it up?!?!?

tzoid9

I really think you are construing the owners manual wording. The exact same words "if equipped" are shown on page 192 of the 2016 manual. The "if equipped" comment refers to the HSA being standard equipment in an M7 and not in the A8. The HSA feature is supposed to kick in if the car is on an incline (and possibly a decline, I believe) of 7 degrees or more and as Bill had indicated, is an aid when syncing the operation of letting the clutch out and accelerating as the car is attempting to roll back (or forward) due to the incline/decline. I know it is STANDARD ISSUE on M7 cars in 2016 and likely the same in 2015. To end all this argument, there should be some A8 owners reading this thread who should be able to tell us if the automatic transmission car has this feature. If it does, it'll be a one of a kind feature that just doesn't exist, IMO, in cars anywhere, with an automatic transmission.

383vett

My wife's BMW X3 and my Range Rover Sport both have the hill assist feature with automatic transmissions. As another member mentioned, Mercedes and Lexus have this feature also.

tzoid9

well, I'll be darned! I currently own 2 MERCEDES + the Z06....one's a 2014 (550E) and the other a GLK (2016). Neither has hill assist. Can't speak for the Lexus, but I had a 2013 GTR before this 2016 Z06. Neither of the M/B's (of course automatics) had hill assist. Sure you know what you're talking about? Germans don't like gadgets in their high end cars, and that's what HA would be in an automatic. Japanese love gadgets...but it wasn't in the GTR, one of Japan's highest priced cars. But you said it, not me. What kind of transmission do you have in your C7 Z06 and does it have H/A?

NSC5

Most full size GMC/Chevrolet pickups (including automatic) have also had hill assist for a number of years.

383vett

We should make a list of newer cars that DON'T have this feature!

tzoid9

[QUOTE=383vett;1593889627]We should make a list of newer cars that DON'T have this feature! [/QUOTE

OK, getting bombed here. New pick ups with auto transmissions and hill assist....yikes! Now, are you sure it's hill assist? How long will it hold the brake on once you take your foot off the brake pedal? Just how difficult is it to take your foot off the brake in an auto transmission car and stab the accelerator? Are you sure it's a true H/A like a manual trans car might have?

tzoid9

[QUOTE=tzoid9;1593889683]ok, just thought of something else. In my previous post, I pointed out on p. 192 of the 2016 Z06 O/M, the Hill Assit comment "if equipped". My M7 has it as standard equipment. If it was standard in an A8, then that " if equipped" comment wouldn't be necessary...so various people are saying the A8 Z06's have it. Show me where the option is on the line order for any one of those A8 cars. That would end this argument.

NSC5

[QUOTE=tzoid9;1593889683]I believe the pickup truck has a short hold time compared to a C7 setup. I have never driven one (still holding onto my 2006 GMC 2500HD with the Dmax/Allison combo) but I could see where some would find it helpful on a boat ramp to avoid launching their pickup along with the boat I agree that it is something most would never miss with the automatic transmission.

tzoid9

[QUOTE=NSC5;1593889920]Well, if you really aren't sure, could it be possible that your stated new GMC pickem up truck has an optional trailer towing package (H/D brakes, different rear end axle ratio, etc.) and part of that includes hill assist so when you're towing some big load, it doesn't get away from you on a hill? That may be part of the towing package (which used to be an option), but is it standard equipment on all GM pick ups?
And, why haven't we heard from one of the many A8 Z06 owners on whether they have H/A or not....and was it standard equipment or an option and if an option, what was the option number???

thebishman

[QUOTE=tzoid9;1593890454]My 2016 Yukon Denali comes standard with 'Hill Assist'. It is becoming pervasive even on 'autos'. It last about 2-3 seconds when your foot is removed from the brake pedal in the Denali.
Bish

tzoid9

[QUOTE=thebishman;1593900484]well, this is really interesting. Neither of my relatively new Benz's have it, but your Denali (another truck frame) has it. I'm still waiting to hear from a C7 Z06 A8 owner to tell all of us M7 owners if they have H/A. I'm just old fashion I guess. To me, it's a worthless add on in an automatic transmission CAR! Besides that feeling, if the A8 has it, why does the owner's manual say "if equipped"? Besides that, I never saw an Option when I spec'd out my car for H/A. Now where are any of the A8 owners in this debate? Do they or do they not have H/A?

ElCid79

I have a 16. The ebrake does auto release as described in the manual.

tzoid9

that's nice to know, ElCid, but that's not the question. The question is does your A8 have Hill Assist....and if aren't familiar with that term, you likely don't have it.

madrob2020

Really bored, so went back looking for info on Hill Start Assist (HSA) & Electric Parking Brake (EPB). Found this very helpful video. Don't know how to provide link so just type this in & view. Video is only 2:15 & he does mention at 28 sec mark, that HSA comes on M7 & A8, but doesn't mention if standard or optional. I'm just making a WAG that it is part of a pkg & therefore isn't specifically mentioned on window sticker. Link:youtube.com/watch?v=i3KNxu3pS74. Follow standard upper/lower case rule. Sun finally came out & warmed up after 7 days so off I go w/top down to listen to my newly installed Borla X-Pipe! Yee hi!