BCM pinout

stickypoop

Well-Known Member
#1
Looking to pick up on the reverse lamp circuit at the BCM. I've found sources that indicate it may be a light green wire, but there are several of them back there. One of which is a com wire that didn't take kindly to having a test light on it...

anyone have a pinout for the connectors or a better idea of what wire to go after?

2004 Envoy
 
OP
OP
stickypoop

stickypoop

Well-Known Member
#3
Very useful, thanks! It would appear the connection I was searching for is actually a ribbon cable. The business end of that would be buried into the box... looks like I'll be tapping into a wire on the exterior after all. :duh:
 

MRRSM

Lifetime VIP Supporter
#4
Cool Beenz... I might as well drop the rest of the PCM PINOUT Images here. This way... Your Post will be the FTW On Topic Posting for the subject and will attract other interested Members as well...

(Lurkers are ALWAYS Welcome at GMT Nation, Too)... :>).

upload_2017-4-25_20-37-25.png


upload_2017-4-25_20-34-21.png
upload_2017-4-25_20-34-43.png

2004trailblazerpcm4-jpg.73337.jpeg
 

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#5
Looking for BCM info for my 04 XUV. Specifically which connector to separate and jump pins, looking to trigger gate latches, manually move roof.

Dealer was going to do a TechII test overriding sensors, no luck, refunded my $130.00 (nice!)

Learned tail gate window sensor showing window 1/2 way up but is stuck full down.

Roof in 80-90% closed position. Beyond tailgate window motor being shot no known reason the latches, roof should not work.

A way to fool BCM into full up would be cool to start with and see.

Since that part isn't made I'm likely never trying to replace it. I need a truck and would like the gate to drop for sure. Roof to slide open too.

Otherwise I'll end up removing tail glass and roof completely for now and just work on the gate....

Thank you in advanced.
 

MRRSM

Lifetime VIP Supporter
#7
When time permits... have look at the images included in Post #26 at this Link to consider investigating "The Umbilicus" that necks through the Hinge Area of the Tailgate by pulling the Grommet(s) free and searching for any Pulled, Stretched or Broken Wires. Perhaps the problem lies there ...and not with any of the other gear that seems to be creating the intermittent issues.

The Wiring within that Bundle not only includes Power Positive and Ground Wires... but also Class 2 Wiring as well... and if any of the Modules serviced through that 'conduit' have any breaks or damage... the adjacent Modules and Motors may suffer as a result:

https://gmtnation.com/forums/thread...repaired-instrument-cluster.18272/post-554794
 
#8
Yep probably. Inspection of wires done. Switch contacts at overhead console appear new. wires checked from there back are good. I have the obligatory rear window defog connectors hanging back there. No connector or wiring issues found after thorough inspection otherwise. Moving on from tailgate to ROOF motor. Hoping to find pin nuber / wire color to ground and see my ROOF close. Will check out your link thank you!

Scoured the info. I see it's related to a standard Envoy with Lift Gate LFG. Great info! However XUV specific info sought. Someday I wanted to get a China Tech II scannner, looks like that is a PITA to work with.
 
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MRRSM

Lifetime VIP Supporter
#9
If you are Standing at the 'The Gates of GM Module Hell'.... even if you slip, fall and get stuck for a while down inside that Purgatory... The ONLY inexpensive way out of there ...is by getting your hands on a "GMYKO" Tech2 Scanner so you can Ping and See which (or Test All at once) Modules are on the Databus Single Wire Network and functioning... and which are acting up. Visit this link if you become serious about getting the Complete Tech 2 Clone Kit for $330.00 and maybe $10-$15 more for the "HWK" (Hard Ware Key):

https://gmtnation.com/forums/threads/new-complete-kit-gymko-gm-tech-ii-scan-tool.17878/post-556060
 

MRRSM

Lifetime VIP Supporter
#10
Yes... I can see what you mean about how different in the "X"treme your vehicle Electro-Mechanical apparatus is ...as shown in this video:


Perhaps the solution can be found by pulling that overhead Push-Button Console and checking just the Button Contacts related to the Overhead Latch-Motor for Color and Continuity when being actuated. Never having seen this unique set-up before... it would be interesting to know if all of the wiring works strictly on (12) Volts with Body Grounds that sidesteps any interface with the PCM entirely.

If the apparatus can function with the Key/On in the Accessory Position without the Engine running, side-stepping the PCM-BCM ... then there might be simpler solution to be found for the Latching-Un-Latching issue. Perhaps this would explain why there are no Wiring Diagrams available that show the PCM-BCM stuff ... if there are none.
 
#12
Thank you! buwich... Appears the the power roof module just sends 12v to the BLUE for open and PURPLE for closed. Surprised we're not grounding a signal line as done with the tailgate window tap.

Thank you! MRRSM, I thinnk I'm ready to move on to the Tech II clone. Thank you for that link, checking it out now.

NOTE: I too wondered about the contacts on that membrane switch in the ceiling console. IT'S ONE MOTHERBOARD (not three separate switches). Already checked it out. The roof contacts show only the faintest hint of wear, the endgate glass contacts looked virtually unused. I took a little steel wool to the ONLY working button, the midgate limo window, that looked nasty. Works perfectly though. It's inability to enter re-learn (close or open roof in DIC) is the real issue.
 

MRRSM

Lifetime VIP Supporter
#13
Okay… This Information looks very promising and interesting:

THIS Link leads to a discussion of the GMC XUV Electro-Mechanical Windows and Lift-gate(?) Latch Locking and Release Operational Problems:

https://www.justanswer.com/gm/6leb7-manually-release-mid-gate-2004-gmc-envoy-xuv.html

..and THIS is a GMC XUV Wiring Diagram worth Downloading that may be precisely what you have been looking for... and can be much better interpreted by @budwich than yours truly:

http://ww2.justanswer.com/uploads/jettadan1/2012-05-01_022134_fullshot.pdf

...and if it comes down to cases and you need a Replacement Overhead Switch Console, there is one here on eBay:

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=gmc+xuv+overhead+switch&_sacat=0
 

budwich

Well-Known Member
#14
Thank you! buwich... Appears the the power roof module just sends 12v to the BLUE for open and PURPLE for closed. Surprised we're not grounding a signal line as done with the tailgate window tap.

Thank you! MRRSM, I thinnk I'm ready to move on to the Tech II clone. Thank you for that link, checking it out now.

NOTE: I too wondered about the contacts on that membrane switch in the ceiling console. IT'S ONE MOTHERBOARD (not three separate switches). Already checked it out. The roof contacts show only the faintest hint of wear, the endgate glass contacts looked virtually unused. I took a little steel wool to the ONLY working button, the midgate limo window, that looked nasty. Works perfectly though. It's inability to enter re-learn (close or open roof in DIC) is the real issue.
I think you misunderstood the pdf that I posted.... maybe.
Look closer at the diagram... you will see that the system indeed grounds or powers the motor accordingly. Its is the "standard flip"... basically the controller puts power on one lead and grounds the other to go in one direction and reverses the operation to go in the other.... So basically that's all you have to do to get the motor to move... assuming that the track system is indeed "good". Nothing really "mystical". Of course, you need to look closer at the system mechanicals to see why it is in its current state... there IS a ROOT cause for your problem.
 

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