9C3 trunk release

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storm9c1
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Location: Pittsburgh, PA

9C3 trunk release

Post by storm9c1 »

Has anybody gotten stranded yet by locking their keys in the trunk? I did. Unlike the B-Bodies of the old days, the trunk button on the 9C3 console DOES NOT WORK if the key is not turned on! Be careful. I was loading my drum kit in the trunk while talking to a bandmate, keys in hand since I just opened the trunk. Somehow I was distracted and either threw or dropped the keys in the trunk, possibly to free up my hands while I was loading the drum kit. I still don't know how it happened. Either way, my friend took off, and I didn't realize where my keys were, and closed the trunk. Luckily the doors were unlocked. So I thought I was off the hook and I could simply press the trunk release button. Nope. No soup for you!

Since my friend was gone, I was essentially stranded with very few resources at my disposal. I keep various bits of wire and tools in my older cars. But my new Caprice is clean. Why should I need tools or parts in a new car? Hehe, well it took me about 15 minutes to track down the trunk relay under the kick panel, and using a staple from some paperwork in the glove compartment, I was able to short the correct pins on the relay to trigger the trunk release mechanism. Thank goodness the trunk pop relay had constant power. Otherwise my GF would have had to drive over an hour late at night to bring me the spare set of keys. This accident prompted me to think about wiring up a hidden trunk pop button under the dash in case this happens again. I'm just too spoiled by the old B-Bodies that would let you pop the trunk at any time.
Tom (AKA: Storm)
2011 Caprice 9C3: L77, 8K miles, first-owner, purchased July 2011.
1995 Caprice 9C1: LT1, 178K miles, summer car.
1995 Impala SS: LT1, 21K miles.
1995 Caprice Wagon: LT1, 62K miles.
1995 Caprice Wagon: LT1, 128K miles. Rust In Pieces
1994 Caprice 9C1: LT1, beater winter car.
1969 Chevy C30: 383ci stroker, 4L80E, rollback car hauler.
1972 Chrysler Newport: 400ci big block, survivor 27K miles, 2-door hardtop.
1969 Dodge Charger: 383ci big block.
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elc32955
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Re: 9C3 trunk release

Post by elc32955 »

That's interesting the relay would have constant power to it, glad it worked out for you. Until I re-read your post and saw "no tools" I was gonna suggest just disassembling the back seat since the Caprice does have the same back seat access slots as the G8 does, but in our cars they made the rear upper all one piece. Can't have the prisoners crawling into the rear and using the trunk release cord to escape. Probably the same reason they didn't put the coat hooks in, can't have people hanging themselves with their shoe laces... lol.... although on that one I think GM was just being "thrifty".

Sort of scary though. You also have the scenario of having a key lost or damaged while the car is locked up (sewer drain anyone?). I don't even know if one of these fat keys with the transmitter would fit into a magnetic key holder you could stick somewhere under the car, you'd probably have to bag it securely & tape it to something while the car was on a lift. And hope like hell when you need it you're not wearing good clothes. I haven't seen a key option without a transmitter yet, but that would just get you basic access without start due to the security features.

Checked the technical guide for upfitting and there's not even a peep about the decklid release. If you do decide to make the mod as you described, take some pics & write it up for everyone!
System Manager and your tour guide for the day. 2015 Caprice w/LFX, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, SS MyLink radio upgrade, 2016 Camaro V6 rims, GMPP Malibu chrome exhaust tips, otherwise bone stock for now.
Navy Lifer
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Re: 9C3 trunk release

Post by Navy Lifer »

Because I've got a G8 leather interior waiting to install, with heated seats, the PPV on-console trunk release will need to be re-located back to the storage compartment/glove box. The PPV's 2-switch plate (trunk release & traction control) on the console goes to a 3-switch panel, with each of the seat heater controls on right & left, and traction control on/off select in the center position.

Currently, the PPV glove box has a blanking plate in place of the trunk lid release button/switch, but the port for the switch is there. I've done some research and parts accumulation but have not done the actual change.

The only thing I'm not sure of is whether the G8-style trunk release is powered all the time or only with the key on. I've got access to a local G8 and will check on this. With the glove box being lockable, I will guess that the trunk release, in G8 form, is able to actuate without the ignition key being "on".
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storm9c1
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Re: 9C3 trunk release

Post by storm9c1 »

Yep, I had no tools, so couldn't disassemble the back seat. Though I tried anyways. It was the first thing I looked at.

As for my own switch, I saw the blanking plate in the glove compartment and considered putting a switch in there. I may still do so. But this would require me to drill a hole or otherwise modify the car. Considering mine is a Criswell car, I'm going to keep visible mods like this to a minimum. On the other hand, a hidden switch under the dash could use an existing mounting surface, I found a few areas that already had holes waiting for me to stick a switch in. Plus it's close to the relay, so running wires will be easier.

The next problem is that the trunk solenoid draws 4A (already measured it). Most small pushbutton switches (at least the ones in my parts bin) are only rated up to 3A. I may go ahead and use a 3A switch anyways, knowing it will only be used in emergencies. Or I'll have to special order a small 4A+ version. I am getting a new washer and dryer this weekend, maybe I'll try to yank the door switch off the old dryer! Hmmmm. That sucker should be rated for high current. LOL
Tom (AKA: Storm)
2011 Caprice 9C3: L77, 8K miles, first-owner, purchased July 2011.
1995 Caprice 9C1: LT1, 178K miles, summer car.
1995 Impala SS: LT1, 21K miles.
1995 Caprice Wagon: LT1, 62K miles.
1995 Caprice Wagon: LT1, 128K miles. Rust In Pieces
1994 Caprice 9C1: LT1, beater winter car.
1969 Chevy C30: 383ci stroker, 4L80E, rollback car hauler.
1972 Chrysler Newport: 400ci big block, survivor 27K miles, 2-door hardtop.
1969 Dodge Charger: 383ci big block.
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ZerOne
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Re: 9C3 trunk release

Post by ZerOne »

Oh wow !
Im sure Holden / GM didnt think of this with the PPV.

Yeah the G8, and Commodore models Trunk release button has a constant power feed, so as long as you have physical access to the cabin and the glove compartment, you can pop the trunk using this button.
There is also a failsafe cable located just behind the centre rear seat (On these models, you can pull the centre seat down to reveal a ski port hole), and the cable is located just behind there.

But I think with PPV, Holden / GM were worried about crims getting access to the trunk area, hence the rear seat that does not have the fold down centre, and the Accessories powered boot release.

As for retro fitting the G8 trunk release switch, there should be largish connector which allows you to connect a glovebox wiring loom.
There are a couple of looms (On RHD models) available, for different variants and options.
I am thinking the PPV might be the same as our local Ute models, where there is no glove box wiring loom present.
(Hence the missing boot release switch, and blanking plate).
There are options for things such as the boot release switch, glovebox lamp, and for Series I (Australian models) Can, Power, and other wires for the Sat Nav function. (Though I am unsure if this is all available on export Left Hand Drive Models).

Here is an example of a Series I glovebox wiring loom, with the Nav option (Includes boot release and glovebox lamp wiring)

Image

And here is the location of the Glovebox loom plug on a Right Hand Drive Model.
(It is normally tucked up behind the metal bracket bit, but I pulled it down for this picture.

Image
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ZerOne
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Re: 9C3 trunk release

Post by ZerOne »

Oh, and this blanking plate can be removed, and behind it you will find a hole already made for the Boot release switch.
(Which means no drilling or irreversible modifying the interior of you car).

Just source a boot release trim bit from a G8, and away you go !

Image
Navy Lifer
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Re: 9C3 trunk release

Post by Navy Lifer »

I'm liking that "light urban" interior!

I have a couple of harness and switch options - one harness is G8, the other is PPV, just so I could see what the interface is between the release button behind the compartment door BEFORE tearing things apart--the parts weren't expensive, so it's worth it for the knowledge base. There is a second button option, just don't recall where it came from as a source.

Here are the PN's:

92172574 harness (G8) Parts group 2.480 - I/P Compt Lp (Lamp?) wiring - includes connector for trunk release button

92056727 pb switch (G8)

92185783 harness (PPV)

92257856 pb switch ? - alternate, need to confirm application

The PPV does have a light in the compartment, and the 2 circuits (lamp & release switch) seem to run in a common harness from the lower rear edge of the compartment assembly.

Given the mention of the amperage draw of the trunk release actuator, and that use of the RKE release command means that the BCM is involved, is the in-compartment release button, when pushed, going to function as it does in G8, or is this a situation that calls for a change (software code) in the BCM flash program?
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storm9c1
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Re: 9C3 trunk release

Post by storm9c1 »

Navy Lifer wrote: Given the mention of the amperage draw of the trunk release actuator, and that use of the RKE release command means that the BCM is involved, is the in-compartment release button, when pushed, going to function as it does in G8, or is this a situation that calls for a change (software code) in the BCM flash program?
I am wondering the same thing. I think the BCM is involved somehow because the trunk release doesn't work without the key on. And the wireless remote has a trunk release button that would be controlled by the BCM -- which works regardless of the ignition. The emergency switch I had in mind will completely bypass the relay in this event. I don't think a stock G8 switch will save us if the BCM is indeed involved. But if anyone can confirm my supposition, let me know. Without the schematics in the FSM (yet), I really don't know how the logic for the trunk release is ultimately controlled.
Tom (AKA: Storm)
2011 Caprice 9C3: L77, 8K miles, first-owner, purchased July 2011.
1995 Caprice 9C1: LT1, 178K miles, summer car.
1995 Impala SS: LT1, 21K miles.
1995 Caprice Wagon: LT1, 62K miles.
1995 Caprice Wagon: LT1, 128K miles. Rust In Pieces
1994 Caprice 9C1: LT1, beater winter car.
1969 Chevy C30: 383ci stroker, 4L80E, rollback car hauler.
1972 Chrysler Newport: 400ci big block, survivor 27K miles, 2-door hardtop.
1969 Dodge Charger: 383ci big block.
Navy Lifer
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Re: 9C3 trunk release

Post by Navy Lifer »

Well, if the BCM is involved, I don't know if there will be any way, short of creating a separate circuit, to do what we're talking about--unless it's a simple TechTool on or off command that a dealer can manipulate to provide power with key off for trunk release. The circuit for the trunk release button on console would have to be identified and re-routed to the glove box button, then a power source identified--I will assume that the console release button works through a relay (or the BCM) and does not see the high amperage of the actuator, but it remains a key-on function only, unlike G8.

That G8 FSM on CD might come in handy....
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storm9c1
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Location: Pittsburgh, PA

Re: 9C3 trunk release

Post by storm9c1 »

Update on this. Using a multimeter and test light, I was able to confirm that the trunk release relay is always hot (fed 12V+). This makes sense since the key fob needs to be able to release the trunk at any time. I also determined that the BCM grounds the relay, thus activating it.

So I was able to add a low-current override switch to trigger the relay by sending it a ground signal.

Here is how:

1) Obtain a piece of thin wire, bell wire or 20-22 gauge stranded. If stranded, strip and solder the tip about 1/4".
2) Yank the trunk release relay (top right relay in the fuse center -- under the driver's side kick panel, hidden by fascia).
3) Using a flashlight or other light source, study the relay receptacle. Become familiar with how the relay plugs in. This can be tricky since the relay is behind part of the kick panel fascia.
4) Shove the piece of stripped wire into the female receptacle -- for the bottom rightmost pin of the relay. See diagram below.
5) Replace the relay (NOTE: the relay is mounted horizontally with the words (Omron) upside down). This should pinch the wire in that bottom right pin of the relay, allowing the relay to function normally and provide an override. This also makes it a completely reversible stealth mod.
6) Hide a momentary (normally open) pushbutton switch under the dash -- it can be a low current switch since all it needs to do is activate the relay. There are lots of locations under the dash where you can mount a switch, lots of brackets with free holes in them, etc. I chose a spot that was easy to reach from the driver's position. There is a metal bracket with two holes just above the driver's kick panel where the lower dash attaches (near the hood release). This is perfect location.
7) Run the relay wire to the hidden switch pushbutton switch -- connect to switch (solder or screw terminals).
8) Run other wire from switch to a ground point, any metal surface, add a screw or undo an existing screw.
9) Test the hidden trunk release. Should pop the trunk no matter what. Perfect if you don't have your keys or if you locked your keys in your trunk an hour away from home (like I did).

It may also be desirable to add the stock trunk release switch to the glove compartment. If you decide to get this switch, it can be wired the same way to bypass the BCM.

Take your time when doing this mod. Make sure you have the correct pin on the relay. X marks the terminal you need to attach the wire. Should be terminal marked 86 on the relay:

Code: Select all

o  o  o
o     x
Tom (AKA: Storm)
2011 Caprice 9C3: L77, 8K miles, first-owner, purchased July 2011.
1995 Caprice 9C1: LT1, 178K miles, summer car.
1995 Impala SS: LT1, 21K miles.
1995 Caprice Wagon: LT1, 62K miles.
1995 Caprice Wagon: LT1, 128K miles. Rust In Pieces
1994 Caprice 9C1: LT1, beater winter car.
1969 Chevy C30: 383ci stroker, 4L80E, rollback car hauler.
1972 Chrysler Newport: 400ci big block, survivor 27K miles, 2-door hardtop.
1969 Dodge Charger: 383ci big block.
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