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Automatic deck lid pull-down

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Old 06-12-2016, 05:22 PM
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Topgun1954
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Default Automatic deck lid pull-down

Just curious if this topic has been covered here in the past. I have a 2014 Z51. As I'm sure most are aware, the deck lid is a bear to close with the windows up. I believe the 2016's now come with the auto close or "pull down" feature for the deck lid. Does anyone know if that feature can be retrofitted to a 2014 (in my case)?
Old 06-12-2016, 06:49 PM
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Flame Red
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There were many threads on this topic, but no success. Last year another forum member bought all the pull down parts for a 16 and he was going to attempt a retrofit. It requires removing the rear bumper to install the latch bracket from a '16, to accomidate the '16 latch.

He built his own controller to control the pull down motor and mocked it up and got it to work, but was not happy with the controller for some reason so he bought the GM controller (expensive). I have not heard anymore from him since then. It required rewiring the open button on the rear bumper. GM also changed the hatch open circuitry. On the '15 it was a simple wire that light up connected to the dash cluster and light up when the hatch is ajar. On the '16 the latch is connected to the BCM via the GM LAN Bus so it is a whole different animal. It would require an EE to rig something up.

Last edited by Flame Red; 06-12-2016 at 06:51 PM.
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Old 06-12-2016, 10:26 PM
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Topgun1954
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Thanks for your input. Seems that I may just have to either shut it hard or push it down like everyone else is doing.
Old 06-13-2016, 12:08 AM
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Originally Posted by Topgun1954
Thanks for your input. Seems that I may just have to either shut it hard or push it down like everyone else is doing.
The correct way is open the door or have window down and drop the hatch from 12 inches up shuts everytime.

Never close a Corvette rear hatch C6 or 7 with the doors closed and windows up.

You can see the hatch hinges bulge when you do.

The pull down is not needed.

Last edited by 3 Z06ZR1; 06-13-2016 at 12:09 AM.
Old 06-14-2016, 10:31 AM
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An alternative is to buy a c7 Window Valet, for about $130. Makes it easy to open/close the windows, and easy to close the hatch. I used one on my c6 that didn't have the pull-down feature, and it made it a non-issue.

Plus you can pre-ventilate the car in the summer when you're walking towards it.
Old 06-16-2016, 09:56 AM
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jcthorne
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Has anyone looked at utilizing the hatch pull down motor from a C6? Electrically they are much simpler and at first glance, very similar in physical makeup. Perhaps some parts from each would enable an aftermarket solution for the 14 and 15 cars.
Old 06-20-2016, 03:52 PM
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Old 06-21-2016, 09:21 AM
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jcthorne
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Originally Posted by zdr2k
Except it does not work. Car is too tightly sealed.
Old 06-21-2016, 11:56 AM
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Originally Posted by jcthorne
Has anyone looked at utilizing the hatch pull down motor from a C6? Electrically they are much simpler and at first glance, very similar in physical makeup. Perhaps some parts from each would enable an aftermarket solution for the 14 and 15 cars.
I have never seen anyone post about trying to retrofit the C6 latch. Too bad I don't have the service manuals for the old C6 anymore. It may be telling if the electrical connections are similar.

But it does not look similiar to the C7 setup, so I am going to guess that it would take a bunch of fabrication of the mounting bracket to get it to work. That means removing the rear bumper.





Worthy idea, in that bone yard parts for the C6 are cheaper and plentiful over that of a C7. Probably exceeds my fabrication skills.
Old 06-25-2016, 11:09 AM
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So you don't believe your own eyes?


Originally Posted by jcthorne
Except it does not work. Car is too tightly sealed.
Old 06-25-2016, 11:32 AM
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Originally Posted by wonka12_98
So you don't believe your own eyes?
The video is dead wrong on two points. One, no matter how hard you pull down on the handle, if the windows and doors are closed, the lid is NOT going all the way down and latched. That is the crux of the problem.

Second, when its closed part way and you need to push it down the rest of the way, pressing in the center rear of the lid as shown in the video is again dead wrong and will result in a cracked lid in time. Chevy is very specific on this one. You press down on the rear of the two struts next to the window.

Don't know why the 14 stingray in the video works fine by pulling down on the handle but my 15Z and most others that I know it simply does not work. This is why chevy went back to a pull down in 16.
Old 06-25-2016, 09:56 PM
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An easy fix would be for GM to offer a flash for the computer that would lower the windows a couple inches any time the rear hatch is open.

It the GM attorneys fear a new liability, having the windows raise when the hatch is closed, they could program the windows to only lower automatically. Then the driver could raise the windows with the switches located on the door.
Old 06-26-2016, 08:28 PM
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Originally Posted by jcthorne
Second, when its closed part way and you need to push it down the rest of the way, pressing in the center rear of the lid as shown in the video is again dead wrong and will result in a cracked lid in time. Chevy is very specific on this one. You press down on the rear of the two struts next to the window.
Not following you here? The main reason it doesn't close on the first pull down is because of the build up of air pressure within the cabin. All you are doing for the last 6mm is depressing the latch to effect full closure, which is in the center of the hatch, below the glass - there is no pressure build up to vent when doing so - so why would this break the hatch? From an engineering perspective, your statement makes no sense.
Old 06-27-2016, 09:11 AM
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Originally Posted by LIStingray
Not following you here? The main reason it doesn't close on the first pull down is because of the build up of air pressure within the cabin. All you are doing for the last 6mm is depressing the latch to effect full closure, which is in the center of the hatch, below the glass - there is no pressure build up to vent when doing so - so why would this break the hatch? From an engineering perspective, your statement makes no sense.
It makes perfect sense when you realize how thin and fragile the rear edge of the lid is. I did not make this up. Been published by gm several times.
Old 06-27-2016, 01:39 PM
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Originally Posted by copjsd
An easy fix would be for GM to offer a flash for the computer that would lower the windows a couple inches any time the rear hatch is open.

It the GM attorneys fear a new liability, having the windows raise when the hatch is closed, they could program the windows to only lower automatically. Then the driver could raise the windows with the switches located on the door.
I wonder of the makers of the "Window Valet" could do this?

But I am not sure if the BCM in the model 14 & 15 really knows if the rear hatch is open or not. Yes, there is a light on the dash, but it is direct wired to the dash. On the 16, the latch control module is connected to the GMLAN Bus and communicates to the BCM that the hatch is open and then BCM lights the dash warning.
Old 06-28-2016, 10:34 AM
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Default Active Hatch Vent Feature

Maybe the Active Hatch Vent Feature that is part of the C7 design is not working properly? It is described in this article:

http://www.superchevy.com/features/1...7-smart-metal/

The photo gallery within that article shows an exploded view of the parts and how they work. Shape memory alloy materials can return to their original shape even when stretched beyond conventional "yield strength" and it is this feature that makes them useful for an application like this or for specialized springs.
Old 06-28-2016, 11:38 AM
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Except the active hatch vent does not accomplish the desired result. IE it was a faulty design that was abandoned in 2016. The 2014 and 15s are forced to live with the defective design.

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