Help. Exterior door lock/unlock button not working

Daniel123588

Hello,
Hopefully i have contributed enough so far to get some decent assistance.

2012 370z.
Did a door speaker install and came to realize that the passenger lock/unlock button on the exterior of the car is not working. It does not function at all.
Everything else works fine. Door can lock/unlock based on remote and sitting inside. Door opens on the inside and outside, etc. Literally just the button outside doesnt work. The driver side works fine and the trunk lock/unlock button and release works fine.

I have done the following for good measure:

-Took off door panel again, there is def no unconnected harnesses (passenger side only really has one harness).

-Did the window reset (although i didnt have the window problem but just for good measure).

-Disconnected ground terminal, drained remaining charge by pressing brakes.

-Took off the door handle and unplugged the harness going to the button.

I did not actually open up the area where the physical button is as it has lock tite and i would need to change the Phillips head into a flat head with a dremel to take out the bolts as it stripped the Phillips. I didn't do this as even if i opened up, it would just be some sort of chip.

It is too big of a coincidence that it failed after the speaker install. Anybody having this problem?

Any electrical savvy enthusiast that can tell me what to check on this 2 wire harness?

Worst comes to worst i would just buy a new switch but i really dont think thats the problem and would like to trouble shoot first. Anywhere i can check on the BCM?

Lastly, not an amateur here advice is appreciated. Thank you!

s2k_cal88

I don't know how the connectors will fit but did you try to swap the passenger with the driver side to see if the the mechanism/ switch in the handle is ok. Needless to say just for troubleshooting purposes . Just an idea

Daniel123588

Tanks eh brah. Why didn't I think of that....simple enough. Thanks s2k. S2k.... I sure don't miss that tiny car when I had it.
Watch this troubleshooting end of busting both door buttons lol. I'll keep anyone posted if they're interested.

Daniel123588

Ohhhhhkkkk, decided to look into this since i had some free time, doing my friends 350z iron man headlight work..ugh..havnt even gotten to mines yet.

So.
1. Swapped driver side (working) door handle to the other passenger side. did not work.
2. moved passenger side (not working) door handle to the driver side, it worked. So that narrowed down that the button module is not broken...yay i guess.
3. Next want to see if maybe when i ran the 12 gauge (was a headache) speaker wires through the door jam wire loom that maybe a wire got messed up. So i checked the continuity on the passenger side door handle harness and of the two wires, one is ground and one is green (positive). THe ground wire (black) had continuity so that was fine.
4. I traced the green wire and along the way when it hits the interior portion of the door jam harness, it becomes a gray wire. I tested all the wires in the interior of the car for continuity and the gray wire had continuity. Ok soooo
5. I then traces the same gray wire all the way to the BCM and all is well. So this narrowed down that the door lock green wire has no issues.

Heres where it gets interesting. So all this was kind of a headache to do with such little space. So after figuring out the wires are fine and the module is fine, i put everything back together (door panel and handle). For some strange reason it then started working totally fine! Driver side works and passenger side works!

Well thats about it. i have no clue what exactly fixed it. The way the 370z BCM module works seems to be substantially different from other older cars which im sure some of you are already aware like the window problem and air bag light problem, etc. Hey it could be the tiny voltage the multimeter sends through to check continuity, i dunno.

At the end of the day, it works, thank goodness.

Heres some helpful pics.

Remove these two rubber covers to access two 10mm bolts that hold the handle. Driver side has an additional Torx screw while passenger side is just the two bolts.


I used this to make sure the screws down fall into the door. Courtesy of some other member i saw did this. Good idea!


Gotta take off the cables.


Green and black wire from the door button harness.


This is the harness on the interior side of the door jam. one half of the harness isnt used which you can run new speaker wire or whatever puddle lamps if you wanted. Its the gray wire below the yellow wire.


Herre is the gray wire on the BCM with a wire testing the continuity. my eexpensive multimeter broke so now i have this crappy one on the corner that doesnt even emit sound for continuity.



Well just wanted to update my thread in hopes to help others who run upon this. Seems many people dont ever update their threads with solutions


Totally off topic. Heres the retrofit im working on for my friends 350z, soon to do some work on mine. Switchback!! Cheeee!

Knockoutpie

Having the same issue, disconnected the battery last night because I removed all rear panels including pillar airbag panels so... This isn't very helpful on saying how I fix my issue.