i have the same problem. i bought my car in March and neither of the power door locks worked. I have been told it is the actuators, but satan wants about $600 to fix it. Someone told me to buy an alarm from a store like Circuit City or somewhere similar and they could probably fix it. Since they can add power door locks to cars that do not come equipped with them for like $30 per door, they should be able to do the same with mine. Does this sound like it would work?? Somebody with more experience on this subject let me know....
To answer your question though...it is most like the actuator inside the door.