GMC Sierra Classic 2007 Owner's Manual page 234

Passenger's Side Temperature Knob
The passenger's side knob can be used to change
the temperature of the air coming through the
system on the passenger's side of the vehicle. The
temperature can be adjusted even if the system
is turned off. This is possible since outside air will
always flow through the system as the vehicle
is moving forward unless it is set to recirculation
mode. See "Recirculation" later in this section.
Turn the knob counterclockwise or clockwise
to lower or increase the cabin temperature. The
display will show the temperature setting
decreasing or increasing and an arrow pointing to
the passenger will be displayed under and to
the right of the temperature setting.
The passenger's temperature setting can be set to
match the driver's temperature setting by
pressing and holding the AUTO button for
four seconds. Both the driver and passenger
arrows will be displayed.
234
Automatic Operation
AUTO (Automatic): When automatic operation is
active the system will control the inside
temperature, the air delivery, and the fan speed.
Use the steps below to place the entire system in
automatic mode:
1. Press the AUTO button.
When AUTO is selected, the display will
change to show the current driver's set
temperature, delivery mode and fan speed.
Press the AUTO button again within
five seconds to display the passenger's set
temperature.
If the driver and passenger's temperature
settings are not the same, the opposite side
temperature setting will be displayed for
an additional five seconds. To make the
passenger's temperature the same as
the driver's press and hold the AUTO button
for about four seconds.