# Trunk Open Button



## MikeyB3649 (Aug 19, 2011)

So I'm kinda irritated by the fact that we can't open our trunks unless the engine is off. In light of this, I've done some looking around the fuse panels and found that in the drivers fuse panel, there is relay called, "Trunk Open Relay." I've come up with simple schematic of how I think I could wire up a button, depending on what the relay needs to energize. Does anyone have any idea if this is a power seeking or a ground seeking relay? Also, I found out how to get the fuse panel to swing down but I don't know how to get the relay off the block. Any suggestions?


----------



## gman19 (Apr 5, 2011)

Looks from the schematic like it is a positive trigger relay.


----------



## MikeyB3649 (Aug 19, 2011)

gman19 said:


> Looks from the schematic like it is a positive trigger relay.


That's the possible schematic I drew up, assuming it's a voltage seeking relay. Lol. Glad it could pass as a GM drawing.


----------



## backyardcustoms (Jun 6, 2011)

The relay itself is non-serviceable printed circuit board relay and internal to the fuse block. You can trigger it from the BCM. Read operation note on bottom it is positive trigger. Hope this helps. PM if u need any other help or locations of BCM.






















*Luggage Compartment Description and Operation* 

*Rear Compartment Lid Release System Components* 



Body control module (BCM)
Exterior rear compartment lid release switch
Rear compartment lid latch
Rear compartment lid release relay
*Rear Compartment Lid Release Operation* 
*Rear Compartment Lid Release Switch* 

The BCM monitors a voltage signal to the exterior rear compartment lid release switch so that when the switch is pressed, the voltage within the signal circuit is pulled low and in response, the BCM will detect the voltage drop and check the status of the door lock system. If the driver door is locked, the BCM will ignore the exterior rear compartment lid release switch, if the driver door is unlocked, the BCM will recognize the request and will provide voltage to the rear compartment lid relay.
*Rear Compartment Lid Latch* 

When BCM receives a rear compartment lid release command from the exterior rear compartment lid release switch, the BCM applies brief pulse of voltage to the compartment lid release relay control circuit, which energizes the coil side of the relay. The switch side of the compartment lid release relay then momentarily closes, supplying a brief pulse of battery positive voltage to the rear compartment lid latch. The rear compartment lid latch is continuously grounded and when it receives the voltage pulse, it will become energized and the latch will activate releasing the trunk lid so that the trunk lid may be manually raised to an open position.
*Keyless Entry Transmitter* 

The BCM may also get a rear compartment lid release command from the remote keyless entry module. When the trunk button is pressed on the keyless entry transmitter, a rear compartment lid release request is sent to the remote keyless entry module, the remote keyless entry module will then send a serial data message to the BCM to command the release of the rear compartment lid.


----------



## backyardcustoms (Jun 6, 2011)

MikeyB3649 said:


> So I'm kinda irritated by the fact that we can't open our trunks unless the engine is off. In light of this, I've done some looking around the fuse panels and found that in the drivers fuse panel, there is relay called, "Trunk Open Relay." I've come up with simple schematic of how I think I could wire up a button, depending on what the relay needs to energize. Does anyone have any idea if this is a power seeking or a ground seeking relay? Also, I found out how to get the fuse panel to swing down but I don't know how to get the relay off the block. Any suggestions?


 

And ur diagram is correct for a positive trigger


----------



## FatKidsCruze (Sep 2, 2011)

On my 12 Eco I can open trunk with the car running. No mods


----------



## cruzeorman (Mar 31, 2011)

On my 2011 LS6m I can open my trunk with engine running do it every morning at work.


----------



## LucyCruze (Jul 1, 2011)

*cough* make sure the doors are unlocked and your trunk should open... *cough


----------



## NBrehm (Jun 27, 2011)

LucyCruze said:


> *cough* make sure the doors are unlocked and your trunk should open... *cough


With car running:
Step 1: press unlock button on dash
step 2: get out of car and walk to trunk
step 3: press button on trunk to open

OR
rewire the relay, set car on fire


----------



## gman19 (Apr 5, 2011)

NBrehm said:


> With car running:
> Step 1: press unlock button on dash
> step 2: get out of car and walk to trunk
> step 3: press button on trunk to open
> ...


:th_SmlyROFL::blowup::sigh:


----------



## Farmer Fran (Jul 27, 2011)

Mine works about 1/2 the time with the car ruinning. Yes I have tried unlocking with remote and dash unlock.

This car has more bugs than Joe's Apartment.


----------



## MikeyB3649 (Aug 19, 2011)

NBrehm said:


> With car running:
> Step 1: press unlock button on dash
> step 2: get out of car and walk to trunk
> step 3: press button on trunk to open
> ...


Well my car must have issues then because the only way I can open the trunk is with the key FOB, engine off. The black patch above the license plate does absolutely nothing, regardless of if the doors are unlocked or not. I'm taking it in to have the alignment looked at this weekend so I'll have them look at that too. 

In regards to the fire thing, trust me, that won't happen. I was an aircraft electrician on F-16's for nearly 7 years while I was in the Air Force. I was responsible for maintaining the power generation and distribution systems in a plane with over 32 miles of wiring in it. A compact sedan would be child's play for someone with my background. :wink:


----------



## gman19 (Apr 5, 2011)

MikeyB3649 said:


> Well my car must have issues then because the only way I can open the trunk is with the key FOB, engine off. The black patch above the license plate does absolutely nothing, regardless of if the doors are unlocked or not. I'm taking it in to have the alignment looked at this weekend so I'll have them look at that too.:wink:


 
I just noticed you have an Eco....I wonder if the Eco is "different" in the trunk/opening respect from other models...I don't know "why" GM would make it any different, but they could have.

I will have to try to open my trunk with the lid button over the license plate WITHOUT my key fob in my pocket. The 2012 LTZ's have the keyless/prox entry feature with the pushbutton start. That is, if my keyfob is within 3 feet of the car, I can pull on the door handle and it will open, trunk is same way. So, if my doors are unlocked, and my keyfob is NOT within 3 feet...let's see....I'm at work and my car is right there...

Hold on.....

The answer is yes....if my doors are unlocked, the trunk is accessible with NO keyfob in the vicinity...well I learned something from this...


----------



## MikeyB3649 (Aug 19, 2011)

Well the dealer checked on this for me today and found that the button on the trunk itself had a loose wire on the connector. They repaired it and now it works like a champ. Guess my schematic is no longer needed.


----------



## FieroItaliano85 (Aug 5, 2011)

The only trunk release button I have is on the remote....where the F is the button!?!?!


----------



## MikeyB3649 (Aug 19, 2011)

Look on the under side of the trunk deck, right above the license plate. It's that little black square.


----------



## dao0815 (Apr 14, 2011)

I couldn't figure out how to open the trunk without using the keyfob. I had to go the dealer and ask how to open. I felt like such an idiot. I'm glad to see that I wasn't the only one. Whew! I'm not an idiot.


----------



## FieroItaliano85 (Aug 5, 2011)

Well they are usually in the d.amn car!!!!


----------



## NBrehm (Jun 27, 2011)

Yeah took me a little bit to figure it out and I was originally PO'd there was no in the car button. After thinking about it the only reason I am going to open the trunk is to put in or get something out which requires standing back there anyway. after I thought about it that way it suddenly made perfect sense to not have one in the car.


----------



## Kaimumma (Apr 14, 2011)

Have any of you noticed that the trunk doesn't open while in drive? These new cars are so safe I tell ya. I always get so upset when m wife will bang on the trunk signaling me to open it up and all I can think of is....."GOSH DARNIT THERE IS NO GOSH DARN BUTTON IN HERE!" All to realize that I have it in "drive" and have to go back to "park." It doesn't even open in "neutral."


----------



## R1XSTA (Aug 30, 2011)

Apparently according to YouTube vid's. You've gotta hold the unlock button on the dashboard for 5 seconds and that will "open" the boot.


----------



## gfxdave99 (Feb 26, 2011)

2011 eco 6mt and i just have to hit unlock on the dash and my trunk button works engine running or not


----------



## rafaelmd (Jul 27, 2013)

Anyone knows how to retrofit a AMBIENT LIGHT SENSOR to a chevy cruze LT that doesnt have it? so it would turn the headlights in the dark!!!
I tried, used the LTZ button and the LTZ sensor... without success... plug and play seems not to be the case...

How to program the BCM to make this work??

thanks!


----------



## Dragonsys (May 27, 2013)

rafaelmd said:


> Anyone knows how to retrofit a AMBIENT LIGHT SENSOR to a chevy cruze LT that doesnt have it? so it would turn the headlights in the dark!!!
> I tried, used the LTZ button and the LTZ sensor... without success... plug and play seems not to be the case...
> 
> How to program the BCM to make this work??
> ...


I thought Automatic Headlights were standard on all Cruze models... you would have to take it to the dealer and have them flash the BCM


----------



## rafaelmd (Jul 27, 2013)

No success.... they could not (dont want to ) program the BCM to have this function... And after updating the BCM ECU, now my Cruise control doesnt work anymore..........


----------



## Chevy Customer Care (Oct 29, 2011)

Have you spoken with your dealership about the cruise control no longer working? Send me a message if you need my assistance. 

Jackie
Chevrolet Customer Care


----------



## Aussie (Sep 16, 2012)

Check that your stop light globes are not blown as this stopped the cruise control working on my Commodore once. Both globes have to be out although the centre one can still work as this doesn't seem to affect the circuit.


----------



## rafaelmd (Jul 27, 2013)

cruise control back to working ok, the problem was the brake sensor....
BUT nobody can reprogram the BCM to get the DRL ambient sensor to work...
If I bought a nwe bcm from the LTZ model, would it work?
thanks


----------

