On my 2006 Hummer H3 the driver's door randomly locks. The rest of the doors stay unlocked. I'm guessing about 25% of the time the driver's door does this. I simply get out and come back and my door is locked. I then have to go around to the passenger's side and press the unlock. It doesn't seem to matter if I leave the keys in the ignition or take them with me.

One thing that might be playing a roll is the ignition switch. It think it is worn. It has been known to run my battery down if I leave the key in it. Sometimes the ignition doesn't turn completely off. It appears the key does not spring all the way back. I do plan on replacing it if I can figure out which part of the ignition switch I need to replace. Maybe someone can help me identify that part also. There is the ignition cylinder (part key goes in) and then the part the cylinder goes in. Not sure exactly what part will fix it.

But anyway, I'm not sure if that's even related to the door locking thing.

 

Do you still have the crappy OEM battery terminals? They can cause this issue. Could also be the BCM going bad, I believe the door locks are controlled by the BCM.

 

Yes, I still have the factory terminals. I didn't know they cause such issues. Would that still be the case if it is only the driver's door that locks?