I read the manual and Googled a bit, but I can't find any mention of how to release the parking brake if the battery is dead or the electric mechanism has malfunctioned. Anybody know how to do that, or if it's even possible?

 

Really good question and I was wondering it myself. I had a GT4 on the lift the other day (just to see the underside) and had to push the car forward a bit. Total pain to jump in (with LWB's), put the ignition on, put pressure on the brake, then undo the hand brake. I then wondered how to do that with the car's battery disconnected or dead. I looked at the manual and did not see anything about it - does not mean I did not miss it - just notes about how to use the emergency key to get into the car.

 

Are you thinking push start if your battery is dead? Last thing that would come to mind would be releasing parking brake with a dead battery . I would want to get a jump. Now as far as a malfunction goes I would not want to drive the car unless you could disable it. Did you look to see if the barking brake has a fuse? Taking out the fuse may disable it.

 

A lot of you guys do not service your cars but i do - and this electric brake sounds pretty dumb to me. I want to be able to roll my cars around the shop regardless if they have power or not. I doubt if the handbrake system needs power to maintain it's on position, so how do you manually take it off with no battery?

 

I'm thinking of a scenario where some issue might make it unclear whether it's safe to start the car and the electrical system may have a problem, so you want to roll it somewhere for it to be checked out. I suppose the chances of the parking brake having been put on before this hypothetical incident occurred would be slim, but you never know. Although now I'm wondering if there's a manual way to ENGAGE the parking brake if needed or if people in that case should just use their transmission and maybe wheel chocks.

I haven't tested the fuse idea, but I'd be surprised if pulling the fuse released the brake unless keeping it engaged required constant electrical supply rather than just moving something into place that maintained pressure itself. But that would drain the battery, and it would also mean that the battery dying would release the brake -- probably not something you want in normal situations. But that in turn means that electrical power would be required to disengage it, in which case removing the fuse wouldn't work.

 

I have not looked on the 981, but the 997 had a pop-out post in the fuse box that allowed you to hook up a jumper cable, and with the other terminal the door hinge, you can jump the car/energize the power system. I had to explore this the other day at MSR when the lithium battery turned off to save itself.

 

The owner's manual outlines a procedure to open the electrically-latched frunk in case of a drained battery. I would imagine the jumpered power would allow activation/deactivation of the parking brake as well. Neither will be something easy to accomplish along the side of the road.

 

Should not be possible, as you say, system needs to be fail safe.

 

I will be surprised if there isn't a fully mechanical backup brake release in case of a switch/solenoid failure just as there is for the frunk, hatch and gas tank door. The absence would be an unexpected lapse by Porsche's (over) engineering staff.

 

I think it has to be failsafe in that the brake remains engaged if the battery fails when its on the street - but I also think there should be a procedure to be able to roll the car without power for servicing. For instance, I bet if you take the handbrake off like I outlined above, and then pull the power from the battery (i.e. disconnect the cable), the handbrake should remain off - so you can roll the car around a shop while working on it.

I just think it's a complex solution to a simple problem.

Cheers,

Mike

 

By reading this I am assuming the the e-brake goes on every time that you park the car so it has to be released every start....just like a Chevy Suburban?

 

No, you have to press the button to engage it, so you can turn the car off with the parking brake disengaged, and I just last night tested engaging the parking brake without the key even in the slot, and that worked too (didn't try disengaging with no key and foot on the pedal). But the ability to turn the car off while the parking brake remains disengaged doesn't help if you already engaged the parking and now need some alternative means of disengaging it. I agree with others that this seems like an obvious ability that Porsche's engineers would have thought of, but nobody seems to know how this is accomplished, even though Porsche has had electric parking brakes in some model or other for quite a while now.

 

I wish it had that option but no one can tell me if it can be programmed to do that.

 

Just found this thread and joined the forum to say that I'm in a position with a drained battery (left the dashcam connected and went on holiday for a fortnight). Car is in the garage, parking brake was on. I cannot open the frunk because I park with the front under some metal shelving!
I've manually got into the car, I've taken the trim out from around the gear selector and manually moved it into neutral, and then I've realised that I've put the parking brake on (I don't normally) and so I still can't push it back 6 feet that is required to be able to open the frunk to get to the point to attach jump leads.

Waiting for the local Porsche garage to call me back to see if they can advice on how to release the parking brake, because otherwise I can't see what I can do...
Maybe I can get it dragged 6 feet out of the garage :-( It's on some rubber mats which will slide, so that might save it from any damage, but oh my god, I didn't need to come home from holiday to this.

 

Since you can get into the car, I believe you can hook up a charger somehow in the fusebox.