Most remotes require that after you get the battery installed, you have to hold lock and unlock at the same time for up to 30 seconds (varies from vehicle to vehicle) while standing next to the car.
Here is GM's procedure for reprogramming but I think it is for new remotes:
Transmitter Programming
No Tools Required
In the event that a transmitter is lost, program the old and the new transmitters into the memory of the remote control door lock receiver. Up to 4 transmitters may be programmed.
Important
Once the keyless entry receiver enters the programming/diagnostic mode, the programming of the first
transmitter erases all previous transmitter programming information. You must then program all of the
transmitters.
Program only 1 vehicle remote control door lock receiver at a time. If you program multiple receivers simultaneously, the same transmitter could possibly be programmed to more than 1 remote control door lock receiver.
Perform the following steps:
1. Sit in the vehicle driver's seat.
2. Remove the ignition key from the ignition lock cylinder.
3. Close all of the vehicle's doors.
4. Remove the MALL PGM fuse from the fuse panel. Refer to Electronic Diagnosis in Body and Chassis.
5. Turn the ignition lock cylinder to the ACC position.
6. Turn the ignition lock cylinder OFF, then back to ACC within 1 second.
7. Open and then close any vehicle door. You will hear a chime when the remote control door lock receiver enters the programming/diagnostic mode. If you do not hear a chime, start again at step 1. If the remote control door lock receiver does not enter the programming/diagnostic mode after a second attempt, refer to Electrical Diagnosis.
Important
After 7 seconds you may hear a chime confirming successful synchronization. After approximately 14 seconds, you will hear a chime confirming successful programming.
8. Press and hold the transmitter LOCK and UNLOCK buttons simultaneously for 14 seconds.
9. Repeat step 8 in order to program each additional transmitter.
10. Remove the ignition key from the ignition lock cylinder.
11. Install the MALL PGM fuse back into the fuse panel. Refer to Electrical Diagnosis in Body and Chassis.
Validate that all the transmitters that were programmed operate properly. Refer to Keyless Entry System Operation .
? Copyright General Motors Corporation. All Rights Reserved.
Document ID # 397060
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