Intermittent door locks trouble

[dkl]

Recently, I'm starting to experience an intermittent problem with all the passenger door locks. I would press the remote once to unlock the driver door, then press the remote a second time to unlock all the passenger doors. But, every now and then, none of the passenger doors would unlock on the second remote press or thereafter. When this occur, pressing the interior lock/unlock button does nothing to ANY doors (including the driver's door) and pressing the remote multiple times doesn't do it either. The only way to solve it is to use the remote to relock the car, then unlock it again with the remote. After that, everything is working as intended. All of the actuators on the passenger doors can't be going bad at the same time, can it?

Is there a specific module that only controls the locks? Or is it part of a combined module? Has anyone experienced something similar?