If the Transmitter was working prior to Battery replacement, you may need to Resynchronize the Transmitter:Try:Stand within 1.5 m (5 ft) from the vehicle. Simultaneously press and hold the LOCK and UNLOCK buttons on the transmitter for 7 seconds
If that does not work & the Transmitter has been tested for a Transmitting Signal:
Here is Programming procedures:
All required remote transmitters must be available when carrying out this procedure.
1. Open driver's door. 2. Turn the ignition switch to the "auxiliary" position, then turn the ignition switch to the "ON" position and back to the "auxiliary" position four times. Note :A chime from the Generic Electronic Module (GEM) will indicate programming status has been enabled. 3. Turn the ignition switch to "OFF" position. 4. Remove the key from the ignition switch. 5. To program the transmitter, press any key within 10 seconds. Note :If the remote transmitter has been accepted, the GEM will make a chime. 6. If any other remote transmitters are to be programmed, press any button once on each transmitter within 10 seconds. Note : A maximum of four remote transmitters can be programmed to the vehicle at any one time. 7. Close driver door.