2001 Silverado keyless remote stopped working

Hello, and thanks in advance for any help. I have a 2001 Silverado, only 1 keyless remote, and for some reason it stopped working. Doesn't get any response at all. No doorlock cycling, no horn, just stopped working a few days ago. I tested the battery with a meter, shows 3.12 volts. I tried holding the lock and unlock for 7 seconds, at least 10 different times, right next to the truck, no response at all. The auto doorlocks do work, no problem, when I press the L or the U on the arm rest in the truck. I've checked and rechecked the fuse compartments, didn't find any blown fuses. Bad relay maybe? Receiver? Any help would be greatly appreciated. Thanks

Try this first.....
Transmitter Programming

Important
All transmitters which are to be recognized by the remote control door lock receiver (RCDLR) must be programmed in a single programming sequence. If the system is placed in program mode it will erase all previously programmed transmitters upon the receipt of the programming signal from the first transmitter. Up to four transmitters can be programmed. Do not operate or program the transmitters in the vicinity of other vehicles that are in the keyless entry program mode. This prevents the programming of the transmitters to the incorrect vehicle.


You may program up to 4 transmitters, using either of the two following procedures:

Transmitter Programming Procedure (Method 1 - No Tools Required)
Close all the vehicle doors.
Insert the ignition key into the ignition lock cylinder.
Press and hold the door unlock switch.
While holding the door lock switch in the unlock position, cycle the ignition ON, OFF, ON, OFF.
Release the door unlock switch. The doors will lock and unlock to confirm the program mode.
Press and hold the LOCK button and the UNLOCK button simultaneously on one transmitter. After a delay of approximately 15 seconds, the doors will lock and unlock to confirm the programming of that transmitter.
Repeat the previous step to program up to four transmitters.
Turn the ignition switch to the RUN position in order to exit the keyless entry transmitter mode.
Operate the transmitter functions in order to verify correct system operation.

If that does not work carry remote transmitter to dealer and have the parts dept check the output of the transmitter. If it is good, then probably gonna be a bad reciever.