Did they both stop working at the same time??
if not i would say its the small motor in the lock which hs failed, i had one go on mine, brought a replacement second hand lock and exchnage the motor, problem fixed.
if they both went at the same time i would say its probally something else, what that would be thoughi afraid i have no idea!
The two front doors have an outstation each but the rear doors are controlled directly by the BeCM. In my rig, a BeCM failure caused the rear doors to stop locking and unlocking (you can unlock and lock them manually ) as well as some other issues such as the fuel door latch not opening anymore.