GMC 2003 Sierra - Manual (Page 181)

Automatic Operation
Al/TO fAutornatJcl; When aulomatic operation is
acljve Ihe s^tgm will control the inside temperature, Нш
air deiivofY, and the fan speed.
Die the steps below to place the entire system in
automatic moiJe;
t. Press the AUTO button.
When AUTO F& selected, (he display will change to
show the currem dnvar's sel lemperalLire,
delivery mode and fan speed. Press the AUTO
button again within ftve seconds to display
the passenger's set temperature.
II the driver and passenger's temperature settings
are not the same, the opposite side temperalure
setting will he displayed for an additional five
secorvds. To make the passenger's temperature the
same as the driver’s press artd hold the AUTO
button Гог approximately tour seconds,
When auto Is selected, the air corvdiLoning
operalion and air inlet wiN be automatically
controlfed. The air conditioning com pressor will run
when the outside lemperalune is ever approximately
40'^F (4*CJ. The air iniet will normally be set to
outside air. If it's hot outside, Ihe airirilet may
automaticaity switch to recirculate inside air to help
quickly cool down your vehicle. The IlghI on the
button will illuminate in recirculation.
2. Set the driver's and passenger's tomperature.
To find your comfort sotting, start wiih a 74^F (23'^C)
temperature setting and allow about
20 minutes for
Ihe system to regulate. Torn the driver’s or
paasenger^s Side temperalure knob to adjust the
lemiperalure setting as necessary. If you choose the
temperatura setting of 60"F Iha system will
ramain al the maximum cooling setting. If you
choose the lemperalure setting of 90'^F (3-2"C) (he
system vtfili remain at the mq;Choosing either maximum seiting wiJi not cause The
vehicle to heat or cool any taster
Be careful not to cover the sensor located on the
top
qf Ihe instrumertt panel near the windshield.
This sensor regulates air temperature based on sun
load, and also (urns on your headlamps.
To avofd blowing cold air in cold weather. Ihe
system will delay lurnJng on the fan until warm air
is available. The longlh of delay depends on
the engine coolant temperature. Pressing the fan
switch Will override this delay and change the fan to
3 selacied speed,
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