lockdown won't open the doors

The physical key should work. I would (gently) persevere with it. More'n like the 12 volt's the culprit.

 

The door lock probably needs a bit of lubrication to get the physical key to work. my preferred lube for locks is silicone spray.

 

This is precisely why the fob has a mechanical key in it.

 

My preference is powdered graphite. I've used silicone, as well.

 

Did you buy the car new, or happen to try the physical key at the time of purchase to make sure it worked then?

Inconvenient if it is cut for a different car.

 

I've had to use the physical key on my Prius, previous vehicle, and an old Toyota Yaris. Each time I thought the lock wasn't working and the door didn't open. Turned out, as people have said or implied above, that was just REALLY stiff. I wouldn't use enough force to break stuff, but definitely apply a bit of thin or penetrating lube. While technically not a lube, WD40 is a product you may well have to hand and is good for stuff like this as it squirts into the lock and penetrates pretty well.

Graphite is a good lube, but it's not going to penetrate well in this context.

If you get it working, apply a small amount of general purpose (e.g. 3 in 1) oil to the lock and/or key and lock/unlock it several times.

 

WD40 is good for initial use getting the thing open. It just doesn't stay around for longer term lubrication because it evaporates away, so something else is needed after that.

 

Exactly. I should have really explained why I added the last line in my post about oiling afterwards.

 

Hmm...I used to keep my cars a LOOONG time (12-15 years...pre-electronic overload with fragile 22 guage wiring...), and I always regretted ANY use of 3in1 or any oily substance in locks. IMHO, it's just too prone to getting gummy.

 

Maybe silicone spray? Keep it contained though, don't let it dribble down the exterior paint. I forget exactly why, but it's bad for something. Maybe if you ever need a repaint?