GM Service Manual Online
For 1990-2009 cars only

Due to the security method used by the remote keyless entry (RKE) system, the transmitter may have to be synchronized. The RKE transmitter does not send the same signal twice to the receiver because the receiver will not respond to the same signal twice. This prevents the signal from being recorded and retransmitted.

Synchronization will be necessary if one or more of the following conditions apply:

    • The transmitter battery is very weak.
    • The transmitter is replaced.
    • The vehicle battery is very weak.
    • The vehicle battery is replaced.
    • The vehicle battery is disconnected.

Synchronize the transmitter with the receiver as follows:

    • While standing close to the vehicle, simultaneously press and hold the LOCK and UNLOCK buttons on the transmitter for 7 seconds.
    • The door locks should cycle in order to confirm synchronization.