I have a 2002 Ranger XLT. Lately, when I start the engine, ususally when really cold as it has been, the doors automatically lock. Not when I go into gear, not all the time, just on the 1st start of the day.

Is this possibly a warning the battery may be bad? It is 9 years old and never been changed. Just a guess.

 

Mine has been doing this too, not lately as it's been a little warmer, but it happened once and both sets of keys were in the cab =[ Not fun

 

mine did it because my battery was weak...put a new battery in and it doesnt do it anymore