GM Service Manual Online
For 1990-2009 cars only

Important: Loss of transmitter synchronization will occur when the following conditions are present:

   • The batteries on the keyless entry transmitter have been replaced.
   • A keyless entry transmitter has been activated many times when out of range of the vehicle's remote control door lock receiver.

In order to resynchronize a transmitter, press and hold the transmitter LOCK and UNLOCK buttons simultaneously for at least 7 seconds. The horn will sound when the resynchronization is successful.