Cold morning driver door lock freeze

You have water freezing in the latch assembly causing it to stick. Try some penetrating oil on the latch (opposite of the hinge side). If that doesn't work you may have to remove the inside door panel to get better access to the latch mechanism.

door lock may be sticking due to water ingress and maybe sticking due to frost. spray plenty water displacement fluid in /around locking mechanism. you may also need to remove door card and access internals of latch to spray also.

possible deicer when in to window control and burnt fuse

sometimes when it is this cold after car heats up and gets cold again the door mechanism ie latch can refreeze

Exit the vehicle and close but do not lock the doors.Now open the rear door,reach over the driver's seat and push the locking tab down.Close the passenger door and you should be good to go.

part of the problem with being in such a cold place is even tho its so cold there is still moisture in the air. if you door wont close or open, you need to check the latch out and make sure its not just bent. as for not being able to unlock you door. the latching system is connected to the lock and handle. if the latch wont move don't use wd-40 that will make it worse. you need to pull open the door panel and get it greased with a grease gun. wd-40 will not keep the parts moving in that kind of cold. if latch wont reset
when you get it open, it wont close. just grease it up. oh it would help if you get water guard for your windows. protect you parts from freezing. take care.

yes frnd there is one socket at the door side , it is at near hinjes of door that socket is lose, just remove that and place it back.

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Power Door Lock Operation (Front Doors)
The front doors do not have traditional door lock actuators. They have electronically controlled door latches that will operate depending on the status of the door lock system. This status is determined by the front door modules and the last known state of the lock system. If the last known state is LOCK, the latches will not release when the door handles are operated. If the last known state is UNLOCK, the latches will release when the door handles are operated. The front doors are also equipped with red door lock status indicators. The front door modules will supply power and ground to the indicators to illuminate them when the lock system is in a virtual state of lock. The indicators will not continuously illuminate when the vehicle is locked. They will illuminate for approximately 5 seconds after a lock switch activation or after a door handle has been operated and the front door modules are in a virtual state of lock. For further information on the front door latches, refer to Power Door Latch Description and Operation .
I would assume they check for DTC'S - diagnostic trouble codes ?
DTC B3062 Front Door Key Lock Switch Circuit
• DTC B3067 Front Door Key Unlock Switch Circuit
DTC B3849 Exterior Door Handle Switch Circuit
The left front exterior door handle and right front exterior door handle switch signal circuits provide inputs to the driver door module (DDM) and passenger door module (PDM) when an exterior door handle switch is activated. These inputs allow the door module to detect a door open request. The door modules provide voltage to the door handle switches. If the door module detects that a ground is applied for greater than 30 seconds continuously, a DTC is set and the door module will ignore the door handle switch input.


Free wiring diagrams here http://www.bbbind.com/free_tsb.html
Enter vehicle info. year , make , model and engine size . Under system click body & accesories .Then under subsystem click power locks . Click the search button then the blue links

Cadillac CTS Door Handle Repair Micro Switches Replacement 2nd Gen

In my case the latch mechanism was frozen. The best bet for that is to allow it to be heated; hair dryer or something then put WD40 or something on it until i get a new one