HJK1

Had the car 3 months, brand new. Initially, when I put the car in gear, D or R, it would automatically disengage the electronic parking brake. I didn't have to push the accelerator to disengage it. It just stopped working.

Reviewing the manual it shows conditions that need to be satisfied, but they are... and I never paid attention to making sure my seatbelt was buckled first, etc. before, so I'm 99% sure that did not affect it in the past. Never once did it not auto disengage. Suddenly, it stopped and now it never automatically disengages. I've tried every combo/order of things that "need to be done" to get it to disengage (per manual and other responses on this form) and nothing's worked.

Is this a setting somewhere or anyone know what's causing the issue?

1) I'm wondering if it's a setting because I've had other settings not "save". I.e. - the internal motion sensor. I turned it off. Next time I'm back in the car, it's back on. Audio door lock, same thing, turned that off, next time, it's back on. Sometimes when I pick my driver profile, it doesn't start auto adjusting my seat. Sometimes the car doesn't unlock/lock by touching the door handles, just straight wacky and inconsistent electronics.

2) Going through the forum - it's not a car wash issue (didn't wash it), it's not an unlevel ground issue (it's in my garage). It's not a software update issue because I've only had the car 3 months, I haven't taken the car back for service so there's been no update. This is a problem where a working feature has now just stopped working for no apparent reason with literally no other environmental, external, or car setting changes.

3) It's a problem because if I have to accelerate to get the brake to disengage it causes a huge jerk because the system won't disengage unless you accelerate quite a bit. It's not smooth. On top of that, I enjoyed the fact that I have one less button to push every time I start the car compared to my C300 (ignition, parking brake, turn off eco on/off). Happy for you if you don't mind or prefer just manually disengaging it or your car is smooth when it disengages by acceleration but I'd like to get it to auto disengage again by just putting the car in gear.

Much appreciated, thank you!

btshep

just tried it out on mine and it disengages the moment I put it in gear while my foot is still on the brake

superswiss

There is no setting for this. It's supposed to automatically disengage when putting the transmission in gear, provided the driver door is closed and the seat belt is buckled in. If either of those are not done, then it won't automatically disengage. If it still doesn't for you then something is malfunctioning. Given your other electronic gremlins you seem to have, it sounds like there's a bigger issue.

mjb2124

I have the same issue and was told by the dealer this is how it works even though it did not function in this manner the first year I owned the vehicle. I've brought it up to them on 3 separate occasions and pointed out each loaner car I was given disengages when put into gear. I just started to live with it. If you find a resolution, please let me know.

btshep

I know said you followed what the manual lists as conditions so pardon the silly questions....
A. Are you wearing your seat belt ?
B. Is the vehicle on flat level ground ?

These two conditions must be met for the brake to auto disengage upon putting the vehicle in gear. If the vehicle is not on flat level ground the brake only disengages upon depressing the accelerator pedal. If your brake is not disengaging when shifting out of gear and the car is indeed on flat ground then I would bring it in for service to check for a bad sensor or some kind of fault. You could point out the verbiage in the owners manual to your service advisor when they try to give you the 'that how it works' line

HotRodW

#3 sounds like you're describing seizing from brake corrosion. Does it happen every time, or only if the car is parked wet?

HotRodW

My car every single time it's parked wet and sits for more than a few hours ...

mjb2124

For me, the car is on a flat surface and I am wearing my seat belt. I made sure all of the conditions are met. I wonder if there is a faulty sensor that does not think the car is on flat ground. Again, this worked the first 8mo I owned the car. I have to take it back in anyway as I have whistling coming from the drivers side mirror at highway speeds. They replaced the mirror last time I was in for service, but the whistling is still happening.

HJK1

Yes - that's what's frustrating, I am wearing the seat belt, vehicle shows it's on flat ground (in garage, the vehicle shows 1 degree slope), door is closed, and obviously my foot has to be on the brake to put the car into gear, at that point I expect it to auto disengage and it does not.

HJK1

Ugh, thanks. That's exactly why I was HOPING to figure it out without going to service. I'm guessing they're going to tell me it's working the way it should or they can't replicate the problem to diagnose it.

HJK1

Every time. I don't think it's corrosion, but I could be wrong. It's garage kept. It just seems it's more sensitive and requires more gas to disengage by pushing the accelerator than my C300 does.

HJK1

Jealous! Thanks for confirming that's what it's supposed to do and I wasn't losing my mind!

HJK1

That's what I figured. Thanks for confirming!

HotRodW

Did mods remove video attachment?

HotRodW

I had a video attached to my follow up post, but it has since been removed. Don't know why, but it shows me applying throttle until the brakes finally let loose with a pretty loud clunk.

HJK1

Funny thing is my car sensor is showing it's at a 1 degree slant at most in my garage. Still doesn't wrok. And when it used to work, it would have no problem auto disengaging from ANY parking lot, etc., regardless of any slope.

HJK1

Yea. For me, there's no "clunk" or other noise. It's more of, it's really trying to hold onto the car and wants to make sure you're actually intending to go. So when it finally gives in, it lunges.

superswiss

That sounds like a sensor issue somewhere. This happens for example if you don't wear the seatbelt. It then doesn't wanna auto-release the parking brake even if you give it throttle, but I think it let's you overcome it with enough throttle. Normally, the auto-release of the parking brake, like after when you engage it manually, doesn't take a lot of throttle to release it. As soon as there is enough engine torque to keep the car from rolling back give the slope of the road, then it will release. For example if you engage the parking brake to start on a hill. You have to give it just enough throttle for the engine to hold the car on the hill and then it releases the parking brake. Sounds like either your seatbelt sensor or the tilt sensor is on the fritz. Have you hooked up an ODBII reader to see if there are any fault codes?

HJK1

Fixed! Apparently a software update fixed it. Doesn't explain why it suddenly stopped working, but whatever. Had dealership look at it while it was there for some other stuff.

Frenetic

Software updates are the “I’m not sure what’s wrong” cure-all attempt at a fix that the dealers will typically do. Sometimes it works, sometimes it doesn’t. I think there’s some placebo effect in that the simple matter of updating the software sort of resets everything, but it doesn’t necessarily always address any underlying issue.

mikapen

Often true, sometimes with my phone, and always with my Quicken.