[DaveC113]

I recently had something crazy happen!

I normally park my car (M6) in the garage with just the e-brake on, it's basically level, but has a slight grade toward the garage door.

It turns out that the car will engage the hill assist after it stops, but it won't release it until you turn the car off and open the door, then a few seconds later it'll disengage. This corresponds almost exactly to how long it takes to get out of the car and close the door.

So I'm heading into the house when I hear a whir sound like the e-brake makes when it's engaging or disengaging, then the car starts to roll backwards! Luckily it's a very slight grade and I was able to get back into the car and stop it before it rolled out into the street.

So don't mistake hill assist for the e-brake, there is a red-light on the dash that indicates when e-brake is engaged but it's definitely possible to think the e-brake is on when it's really hill assist, and hill assist will definitely disengage when you turn the car off, but maybe not until you get out of the car, just in time to watch it roll away.

I know you should leave the car in gear when you park it, and I posted this just in case some don't bother. Well, with the electronic e-brake in these cars it might be best to make sure you leave the car in gear when you park it, and check the dash light to make sure the e-brake is engaged.

[Scottyz]

That’s scary.
Pretty sure there was a couple pics of a blue ZLE in a pond. From what I recall reading I guess he got out of the car and it rolled away, down his driveway and across the road into the pond.
I always make sure the e-brake indicator is on and the car is in gear when I park the car and shut it off.

[DaveC113]

Originally Posted by Scottyz

That’s scary.
Pretty sure there was a couple pics of a blue ZLE in a pond. From what I recall reading I guess he got out of the car and it rolled away, down his driveway and across the road into the pond.
I always make sure the e-brake indicator is on and the car is in gear when I park the car and shut it off.

The timing of the hill assist turning off after the car is turned off is absurd. It's the last thing that turns off and it does it AFTER the driver door is open and then closes, so it turns off AFTER the driver has left the vehicle! If hill assist turned off with the engine it would make a lot more sense.

You can also open the trunk (with the car locked, but the trunk will open if the fob is nearby) and then proceed to lock your fob in the trunk, without ever unlocking or opening the doors, so nobody would be in the car. Yet it'll happily lock your fob in anyways. Don't ask how I know...

GM needs to work on logic a bit more, I know it's very complicated but there are some issues...

[Scottyz]

Agreed!!!

[Jaxcam02]

I miss good old fashioned mechanical ebrake

[Rock-It Man]

I cannot imagine any reason to leave the car in neutral when parked.

[TJay74]

Hill Assist will only stay active for maybe 5 seconds, after that it will release.

[VinnAY]

Hill assist and the electronic E brake are utter garbage.



IMHO.

[Jb54]

Originally Posted by TJay74

Hill Assist will only stay active for maybe 5 seconds, after that it will release.

Why do need it anymore than that? You're only need it when releasing the clutch.

[TJay74]

Originally Posted by VinnAY

Hill assist and the electronic E brake are utter garbage.



IMHO.

I have zero issues with either of them. The electronic parking brake is just that, a parking brake not an emergency brake.

[DaveC113]

Originally Posted by TJay74

Hill Assist will only stay active for maybe 5 seconds, after that it will release.

Could be, it's about the amount of time it takes to get out of the car.

The issue is, when the car's engine is stopped and driver's door is opened, then the assist disengages, it may allow the car to roll away.

The car knows when doors are opened and the engine is off and speed is zero, instead of disengaging hill assist it could just engage the parking brake.

I also agree it's obviously user error, I'm not saying I didn't do anything wrong, I did... But the consequences don't necessarily have to be so severe! The logic involved in the automatic disengagement of hill assist when the car is parked is faulty as well.

IMO owners need to be aware of this quirk so they make sure they hit that parking brake AND keep the car in gear when parking. Hill assist makes it feel like the parking brake is on, this is main danger.

[TJay74]

Originally Posted by DaveC113

Could be, it's about the amount of time it takes to get out of the car.

The issue is, when the car's engine is stopped and driver's door is opened, then the assist disengages, it may allow the car to roll away.

The car knows when doors are opened and the engine is off and speed is zero, instead of disengaging hill assist it could just engage the parking brake.

I also agree it's obviously user error, I'm not saying I didn't do anything wrong, I did... But the consequences don't necessarily have to be so severe! The logic involved in the automatic disengagement of hill assist when the car is parked is faulty as well.

IMO owners need to be aware of this quirk so they make sure they hit that parking brake AND keep the car in gear when parking. Hill assist makes it feel like the parking brake is on, this is main danger.

I just never have ran into the issue. When I am parked my car is in gear before I get out of it and the parking brake on, but I am also parked on a level surface so I dont normally have to worry about it. My parking habits are the same though every time. I never have trusted only using the parking brake or leaving it in gear, I was taught to use both every time so that the only way I do it these days.

I am glad you shared you experience though, it will help others I am sure.

[DaveC113]

Originally Posted by TJay74

I just never have ran into the issue. When I am parked my car is in gear before I get out of it and the parking brake on, but I am also parked on a level surface so I dont normally have to worry about it. My parking habits are the same though every time. I never have trusted only using the parking brake or leaving it in gear, I was taught to use both every time so that the only way I do it these days.

I am glad you shared you experience though, it will help others I am sure.

Yeah, 1.5 years of ownership before I made that mistake. I can see how it was overlooked.

Hearing that whirring sound of the brake disengaging and watching the car start to roll away was a pretty intense experience and could easily end badly! I would not be surprised if that was what happened with the blue ZLE Scottyz mentioned, ending up in a pond is actually a great outcome vs having the car hit someone.

[vtirocz]

Originally Posted by Jaxcam02

I miss good old fashioned mechanical ebrake

Me too!