Got home from work early hours of morning ( below freezing temperatures) went to lock the car with the fob and all locks clicked then it sounded like one or more locks unlocked again red light on door flashed then went constant red. 

Drivers rear door was locked but it felt like the drivers door wasn't but as it was 3 am i didn't want to try and open the door incase the alarm went off waking everyone up. 

Is this a known fault? 

Not sure if it's a sign of up coming problems but as i thought the drivers door had not locked. I tried lubricant in the mechanism and took the lock cover off to access the key slot this was a little stiff to turn but did move and now the door locks as it should