Try shooting a thin penetrant into the lock, and trying it. Do this daily for a week and if it doesn't work, replace the lock. not enough info. are you saying key doesn't work or manually locking by hand won't work, or both, key turns but door doesn't lock??? etc.
It can be a common noun and a verb. Noun: He put the key in the lock. Verb: He wanted to lock the door.
A faulty the door lock sensor will cause the door locks to lock and unlock repeatedly. The door lock sensor is located below the dashboard on the drivers side.
door lock actuator stuck,bad door latch if rear door has child saftey on a bad door entry handle.
Gotta pull the interior door handle while pushing the power door lock down. Common to lotsa hondas.
sounds like the lock soleniod is gone.
A lock on a door knob.
the batterys are dead in the remote or in the car.
There are a number of reasons why your door might not lock. You could have something stuck in the door for example.
replace the lock actuator (motor)
The answer is a key
If the remote locks the door properly that tells me that the wiring and the lock solenoids are operating OK. I'm also taking it for granted that the switch you spoke of is the door lock switch on the drivers door. Does the passenger door switch work properly? If so, then you probably have a bad switch on the drivers door. (IMPROVE) You can remove the door lock mechanism from the panel and gently pry open. Carbon build-up is common on the switches. Use a pencil eraser to remove the carbon and ensure the switch functions properly. Re-assemble.
I can only speak from my own experience, but, I had to fix a seized door lock (drvrs side, rear) last year on my 1997.