GM Service Manual Online
For 1990-2009 cars only

The Universal Garage Door Opener (UGDO) is in the overhead console. The UGDO has battery voltage at all times. In order to program the unit, use the hand-held transmitters from one of the following customer devices:

    • The garage door opener
    • The gate opener
    • The security system

The UGDO system incorporates rolling code technology. This level of security performs the following functions:

    • Prevents anyone from recording the message being sent from the transmitter to the receiver
    • Prevents playing the message back in order to gain access to the customer's personal property

Rolling Code refers to the way that information is sent out by the UGDO and accepted by the receivers. The transmitted signal is scrambled in a different order upon every transmission. The transmitter and the receiver keep track of the appropriate order of the transmitted information. When the signal being sent by the transmitter is not in the order that the receiver is expecting, the following conditions may occur:

    • The transmission becomes invalid.
    • The system becomes inoperative.

The UGDO is compatible with most, but not all, types and brands of transmitters.