Cars equipped with a child safety lock system may sometimes experience a glitch, forcing car owners to walk around and open the doors from the outside for their passengers. This is a problem that can be fixed easily and inexpensively without having to go to the repair shop.
Remove the plastic cover around the child lock lever with a flathead screwdriver, exposing a larger hole to see inside the lock mechanism.
Spray the WD-40 in and around the lock lever, being sure to get the lubricant deep into the child lock mechanism.
Switch the child safety lock off and on several times to loosen it, then reset it. Do this 15 to 20 times. Repeat this process for all doors that are problematic.
Replace the plastic cover over the child lock mechanism and close the door. Drive and see if the problem persists.
If the problem continues, repeat this process but also place tape over the lever, forcing the lever down. Make sure the tape is strong enough to keep the lever in the down position.
If the problem continues, you may want to have the system checked. You may have a problem with the locking mechanism and may need a replacement part.