GM Service Manual Online
For 1990-2009 cars only

The passenger climate control consists of 4 warm and 4 cold LED indicators. The neutral setting will keep the passenger control inoperative. The passenger control assembly communicates with the instrument panel module to vary the passenger air mix actuator setting. Depressing the blue or red buttons causes the system to begin operating in the DUAL ZONE mode. The passenger may raise or lower the passenger side discharge air temperature by pressing the button in the appropriate direction. Passenger offset will be remembered across ignition cycles.

Greater sun load on one side of the vehicle may cause the discharge air temperatures to be different even when the system is not operating in DUAL ZONE mode.