The random locking and unlocking issue has been solved! I replaced the passenger power window power door lock switch and that did the trick.

Here is an update on my post. I can lock/unlock driver door with key. I cannot lock/unlock all doors by moving key twice to left or twice to right. The lock/unlock all button on the power window switches (master/passenger) does not work. i can only unlock all doors except driver door with key fob. A...

Thanks Lee!
I'll give it a shot and report back after some observation.

Greetings fellow Volvo enthusiasts, I have owned this vehicle since Nov of 2013. Since the purchase, in this order I have replaced: -ABS module -Throttlebody cleaned -New clutch installed -New radiator -New air pump (was supposed to get rid of CEL but didn't) -New battery After replacing battery, th...