Passenger Door Won't Open - Not Locked?

My girlfriend has a 2015 Cadillac ATS. Her passenger side mirror was damaged - broken housing, and the light was dangling. I offered to replace it for her.

I ordered a used replacement mirror from eBay. I took off the door panel, swapped out the damaged mirror for the good mirror, reconnected everything, and put the door panel back on. It seemed like it went well, and it was very easy. There were three bolts to mount the mirror, and one electrical connector. The door panel only had the latch cable and a few more electrical connectors. There really wasn’t anything to mess up.


Once everything was back together, I turned the car on and tested the mirror’s functionality. Nothing worked. It didn’t move, the blinker on the mirror didn’t light up, and the light at the bottom (I think it’s called a puddle light?) didn’t illuminate either.

Okay, so I need to take off the panel and start troubleshooting. Step one - open the door, then remove the panel. The door won’t open. I unlock the doors and try again. Still won’t open. I unlock them over and over, and neither handle (inside or out) will open the door.

My first thought was a sinking "oh no, I never reconnected the latch cable to the door handle. I put the window down, and forced a gap between the door panel and the door - just enough for a light to shine in there. I confirmed that the cable is attached, and when I pull the handle, it moves the cable forward, as it should.

I’m not sure what to do next. I want to look at the latch mechanism, but I need to open the door to do that. I want to look behind the door panel at the connections, but I need to open the door to do that too. Maybe I need to replace an actuator? …need to open the door.

I really don’t think the door is locked - I hear the passenger door lock moving when I lock / unlock the car. Does anyone have any ideas?

Oh, and I messed around with the driver’s side door quite a bit to get a better understanding of what might be going on. I noticed the door latch has three positions… open, closed (pulling either handle while unlocked opens it), and a second closed position that doesn’t open when a handle is pulling it. I can’t remember for sure how I got it out of this third “super-closed” position - I think I had to push it open with a screwdriver, while pulling a handle.

Anyway, any help, insight, ideas, or suggestions are appreciated!

Cab you get the door card off if you take the passenger seat out? You could try going to a body shop and see if they can get the door open.

I would read the owner’s manual carefully to see if the system has a “safety” that causes this.
Will the remote unlock it? Is there power to the other functions on the door?

I’m not sure what the door card is. If it’s the panel, then no - when the door is closed, the panel is wedged between the door and the side of the dashboard. No room to wiggle it out, it’s stuck. I’m trying to avoid taking it to a body shop, but you may be right - I’m close to caving and doing just that. Thanks!

When I unlock with the remote, I do hear the passenger door unlock - but it still won’t open. The power window and power door locks on that door still function. The electrical mirror controls do not.

Good thinking on a possible safety - I’ll check the owner’s manual for something like that. Thank you!

Wiggle the gear shifter and make sure it is in Park. Might be worth cycling it in/out several times…