GM Service Manual Online
For 1990-2009 cars only

When transmitters are out of synchronization, all of the buttons except the panic button will be inoperative.

The following conditions are possible causes of a transmitter being out of synchronization:

    • 256 button presses out of range of the vehicle
    • Replacing the transmitter battery
    • Performing the synchronizing procedure out of range of the vehicle
  1. Press and hold the lock and unlock buttons simultaneously on the transmitter being synchronized for 7 seconds,within 1 meter from the vehicle. All doors lock and then unlock in order to provide feedback that the synchronization is complete.
  2. Verify transmitter operation.