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From digest.v7.n741 Wed Dec 10 04:17:15 1997
From: Jim Cash <>
Date: Wed, 10 Dec 1997 00:32:28 -0500
Subject: Re: <ALL><safety> getting locked in trunk

Marc Edwards brings up a good topic.

> Saw an interesting and concerning show on Dateline tonight regarding people who
> get car-jacked and then they are put in the trunk. Some people never are able to
> get out of the trunk because there is either no mechanism that allows them to
> get out of the trunk on their own or they don't know where to start looking.
> Keep in mind too that it is completely dark in the trunk.
> Has anyone in an E36 or other BMW created or manufactured a device
> so that the trunk lid (boot for others) can be opened from the interior of the
> trunk? If so, how did you do that, and would you be willing to share?


Several solutions are relatively easy, and while they may never be used, it should at least bring peace of mind to some people.

Suggestions are is based on an E28 (82 528e) - but should be similar for others.

First the simple, manual, way. ( a light will help ). Remove the rear trunk panel to expose the lock mechanism. (the plastic panel would have to be ripped off the rear of the trunk lid on the E39 - but hey - you want out). There is a metal rod that connects the lock to the "electrical actuator" solenoid. Push, or pull, on this rod to imitate the movement of the solenoid. Once you have moved it far enough, it will kick in and unlock the whole car. Even if it does not operate electrically you should be able to apply enough force to move the trunk lock manually.

Now the electric switch method.
I used this to put a small push button on the underside of the trunk lid, so that I could "lock" the car before closing the trunk - saved having to get my key out. But the same method can be used to have a button "unlock" the car.
The trunk lock (for the E28) has three "control" wires. The brown one is ground. If it is connected to the "lock request" lead (green/black), the car locks. If the ground is connected to the "unlock request" lead (yellow/black) then the car unlocks.
Sorry, but it's that simple.

So all you need to do is select a switch, and location, of your choosing so that it can apply ground to the "unlock request" lead. (and, using a second button, or a toggle switch, to the other lead if you also want a quick "lock" switch.)
I looked at the wiring for the E38/39, and the same unlock function can be performed by shorting the ground and control wires on the trunk lid "open" switch.

CAUTION - The switch will have to be mounted where it can meet the following criteria:

  • can be reached by someone who is possibly restrained.
  • is not so obvious that "the bad guy" will see it, and rip it out.
  • it can not be accidentally operated by items stored in the trunk, especially if it is on the lid and hits stuff when the lid is closed.

To get from the trunk through the fold down seats would have to be a manual process. I am not about to try this, but I know that the rear covers can be pried off. (some destruction would occur when seats are up). It would then be likely that you could manually release the mechanism from within the seatback.

There is also the possibility that someone locked in the trunk may have another remote key on them. They would be very upset if they did not remember that they had it. It could also be used to set off the alarm. If someone was really concerned about this condition another remote key could be purchased and hidden in the trunk.

As a precaution in high risk areas you could "double lock" the trunk with the remote master key and conceal this on your person. Then use the "valet" key in the ignition. If anything happens "the bad guy" will only have the valet key, and can not open the trunk. So you can't get locked in it.


You could always rig another small switch, to parallel the push button switch that supplies ground to the trunk lights.

While you are at it, wire up a small cooler for wine and cheese - just in case you want to wait till they are long gone.

Datís it - eh! Safe hibernating !


Jim Cash
London, Ontario, Canada
BMW CCA 102929
E39 í97 540iA

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