GM Service Manual Online
For 1990-2009 cars only

Press and hold H until the correct hour appears on the display. AM will appear for morning hours. Press and hold M until the correct minute appears on the display. The time can be set with the ignition on or off.

To synchronize the time with an FM station broadcasting Radio Data System (RDS) information, press and hold H and M at the same time until TIME UPDATED appears on the display. If the time is not available from the station, NO UPDATE will appear on the display.

RDS time is broadcast once a minute. After tuning to an RDS broadcast station, it may take a few minutes for the time to update.