if the car battery was discharged then yes the key fob can lose its synchronisation with the car and you should try this process
You must complete each step within 5 seconds of the previous step to keep the
system from exiting the programming mode.
1. Turn ignition switch to ON (II)
2. Press the LOCK or UNOCK button on one of the remotes. (An unprogrammed
remote can be used for this step.)
3. Turn ignition switch to LOCK (0)
4. Repeat steps 1, 2 and 3 two more times using the same keyless remote used
in step 2
5. Turn the ignition switch to ON (II)
6. Press the LOCK or UNLOCK button the same remote. Make sure the power door
locks cycle to confirm you are in programming mode.
7. Press the LOCK or UNLOCK button on each remote you want to program. Make
sure door locks cycle after you push each remote button to confirm system has
accepted the remote.
8. Turn the igniton switch to LOCK (0) to exit programming mode.