Just to confirm what you thought:
Resynchronization may be necessary due to the security method used by the remote control door lock receiver system. The transmitter does not send the same signal twice to the receiver. The receiver will not respond to a signal that has been sent previously. This prevents recording and playing back the signal from the transmitter.
Resynchronization does not send the mathematical formula to the receiver. Resynchronization verifies the previously programmed mathematical formula in the transmitter. Resynchronization works only if the transmitter is already programmed.
Resynchronization may be necessary under the following conditions:
The transmitter is weak.
The transmitter battery was changed.
The vehicle battery is very weak.
The vehicle battery was changed.
The vehicle battery was disconnected.
The transmitter is pressed more than 255 times outside the range of the receiver.
In order to resynchronize the transmitter with the receiver, complete the following steps:
Depress the lock and unlock buttons on the transmitter simultaneously for 7 seconds.
The receiver will acknowledge resynchronization in the following manner:
If all of the doors are locked, the receiver will unlock and lock all of the doors except the drivers door.
If all of the doors are unlocked, the receiver will lock all of the doors.