Toyota Repair: 1998 4Runner, keyless entry system, control switch

Question
My 4Runner is wonderful with low mileage and no problems.  This problem is small but drives me nuts every day when I head for the truck.  The drivers side door remote entry doesn't work at all. All the other locks pop up no problem but I have to manually (I mean really!!! =) key the door open. Is there anything I can do to fix this or do I need to call the dreaded dealer service? Thank you - Leland

Answer
It may be the door lock actuator, does the door lock and unlock when using the switch on the master control switch in the left armrest or is it only with the remote?
When you unlock it with the key do the other locks also open?
Are you able to lock all the doors with the remote?
Is it a factory keyless entry system or aftermarket installed?