I had a similar problem in my old Acura CL and it was the remote buttons not making good contact, i fixed it by putting a piece of foil inside the remote to close any spaces in it.

 

There are two different unlock modes, one where one press unlocks all doors, and another where a single press unlocks the drivers door, and a double press unlocks all doors. You can toggle between those two modes by holding both the lock and the unlock buttons on the key fob down at the same time until the car beeps. Perhaps you are switching modes inadvertently by keeping your smart key in a tight pants pocket with other items, and buttons are getting pressed accidentally as you move about?

 

 

Sounds like a typical yoda lock failure. Pay attention to the ambient temperatures as many fail when too cold or too hot.

PS don't buy door lock actuators from fleebay, you'll regret it!
Maybe check rockauto...

 

do you mean the actuator? HMM.. all 3 of them?

 

update: looks like its the power supply multiplex network computer module according to this thread on the other website
http://my.is/forums/f115/sometimes-d...03/index2.html

 

That thread is talking about the issue on a first generation IS.

 

Yes, actuators. They are weak and as seen on a Rav4, can crap out in pairs. Three seems steep tho. There are several threads on people doing repairs to replace them.

On mine I disabled auto lock/unlock as I drive solo most of the time so the doors are no longer auto locking/unlocking based on speed or gear selection.