My 06 trunk button is not working.

I have verified that the switch grounds out as it should when pressed. Does anyone know where the wire goes so I can trace it down and test it? Hopefully just a broken wire. Does it connect to a body control module or something?

thanks for your help

Chad

 

Do you mean the outside trunk button or the inside one? Can you open it electronically any other way - from the fob, or either inside or outside buttons?
If you mean the inside button near the steering wheel, be sure the "cancel" switch in the glove box is not in the wrong position.
It looks like the signal to the actuator does come from the BCM. If you can't get the actuator to work by any means then I would guess a possible broken wire (listed as G/W color) in the harness which passes into the trunk lid. Ground (Black) passes back out of the trunk lid and connects to the body on the driver's side C pillar. The schematic differs depending on whether you have i-key or not. Here are the pages.

 

Thank you very much, I will do some testing this week end. It is only the button in the tail light that has issue, the interior button and the keyfob all work fine so I assume it isn't the switch in the glovebox.

 

Since the actuator works with other methods your trunk lid harness is OK. The manual is a bit confusing, apparently of you don't have the "Intelligent Key" the "trunk open request switch" (near taillight) IS affected by the glove-box cancel switch. And it only works when the driver's door is unlocked.

With the I-key the fob just needs to be within range of the button for it to function. If it doesn't there are a few more components in play (antenna, fob battery, etc...).

(The manual above is '05/'06.)

 

Are you sure the diagram bl-tlid-03 is for an 06 coupe? If you look at the connector for the outside trunk lid opener switch b132 (which I assume is the switch in the tail light) On my car one of the pins goes directly to ground, and the other eventually goes to the BCM. I think my problem lies somewhere in that path. Unless I am a moron (quite possible) the diagram provided doesn't match up with my car. Please advise and thanks again for your help.

 

Do you have an I-key or not?
Sorry, my manual is for the sedan so it may be no help at all...
But here's another fun illustration of my trunk harness. Note the wires that peal off and lead to that switch (either with or without the I-key) share a moment with the license plate lamps. Are yours working? Just a thought.

 

sorry, a bit more ... if you don't have the I-key (and the coupe is like the sedan) then that 3rd diagram above explains that the goal to make the trunk actuator open is to connect pin 30 of the BCM to ground. Reading from ground point M66 up, it first goes through the passenger door "unlock sensor", then to the "outside trunk lid opener switch", then through the "trunk lid opener cancel switch" to make the circuit.

So without the I-key the front doors need to be unlocked and the glove box "cancel" switch must be in the correct position.

WITH the I-key the circuit is different...

Maybe somebody here has the manual for the coupe and you can get the correct pictures...

 

My car does not have I-key my license plate lights should be working since I had it inspected yesterday but I will check when I get home.

 

I found the correct diagram. Apparently there are several differences between the coupe and sedan. But from looking at the diagram, I either have a bad wire or the problem is in the passenger door lock mechanism.

 

OK, it's not that different ... but the ground goes through your outside switch first. (And you already confirmed that is switching ground as it is supposed to.) Then it travels all the way to the passenger door "unlock sensor" and finally through the glove box "cancel" switch to compete the circuit.

I don't mean to state the obvious but please first be sure the cancel switch is in the right position. Turning "on" a "cancel" switch doesn't make much sense but I believe "on" means you can use the trunk buttons and "off" means you cannot. That "cancel" switch also effects your in-cabin trunk release button so confirm that those two switches are working together as expected.

The next likely culprit as you say is that passenger door "unlock sensor" or the wiring leading from the taillight button into the passenger door and from the door to the glovebox switch. That pair of wires passes through the "hinge" harness in and out of the passenger door so that is a possible breaking point. The wire running from the taillight is marked B/R so black with a red stripe. The one from the "unlock sensor" to the glove box cancel switch is either white (W) or white with a green stripe (W/G), depending on where connector D31 is. And somewhere this links to a blue wire (L) and terminates at pin 2 of the cancel switch...

Keep tracking that ground and you should be able to isolate the problem.