night vision GMC ENVOY DENALI 2009 Owners Manual

There is a delay in the transition between the daytime
and nighttime operation of the Daytime Running
Lamps (DRL) and the automatic headlamp systems,
so that driving under bridges or bright overhead street
lights does not affect the system. The DRL and
automatic headlamp system are only affected when the
light sensor sees a change in lighting lasting longer
than the delay.
If the vehicle is started in a dark garage, the automatic
headlamp system comes on after the transmission
is shifted out of P (Park). Once the vehicle leaves the
garage, it takes about one minute for the automatic
headlamp system to change to DRL if it is light outside.
During that delay, the instrument panel cluster might
not be as bright as usual. Make sure the instrument
panel brightness control is in the full bright position.
If the vehicle is running and the automatic headlamp
system is already on, it can be turned off by turning and
releasing the headlamp control at the off position.
The automatic headlamp system stays off until you turn
and release the headlamp control at the off position
again. SeeHeadlamps on page 3-13.Fog Lamps
The fog lamp button is located on the instrument panel
to the right of the exterior lamps knob. Use the fog
lamps for better vision in foggy or misty conditions.
The ignition must be in ON/RUN for the fog lamps
to work.
#:Press to turn the fog lamps on or off. An indicator
light turns on near the button while the fog lamps
are on. Fog lamps turn off whenever the high-beam
headlamps are on.
Some localities have laws that require the headlamps
to be on along with the fog lamps.
3-15

Driving at Night
Night driving is more dangerous than day driving because
some drivers are likely to be impaired — by alcohol or
drugs, with night vision problems, or by fatigue.
Night driving tips include:
Drive defensively.
Do not drink and drive.
Reduce headlamp glare by adjusting the inside
rearview mirror.
Slow down and keep more space between you and
other vehicles because headlamps can only light up
so much road ahead.
Watch for animals.
When tired, pull off the road.
Do not wear sunglasses.
Avoid staring directly into approaching headlamps.
Keep the windshield and all glass on your vehicle
clean — inside and out.
Keep your eyes moving, especially during turns or
curves.
No one can see as well at night as in the daytime.
But, as we get older, these differences increase.
A 50-year-old driver might need at least twice as much
light to see the same thing at night as a 20-year-old.
Driving in Rain and on Wet Roads
Rain and wet roads can reduce vehicle traction
and affect your ability to stop and accelerate. Always
drive slower in these types of driving conditions
and avoid driving through large puddles and
deep-standing or owing water.
{CAUTION:
Wet brakes can cause crashes. They might not
work as well in a quick stop and could cause pulling
to one side. You could lose control of the vehicle.
After driving through a large puddle of water or a
car/vehicle wash, lightly apply the brake pedal until
the brakes work normally.
Flowing or rushing water creates strong forces.
Driving through owing water could cause your
vehicle to be carried away. If this happens, you and
other vehicle occupants could drown. Do not ignore
police warnings and be very cautious about trying to
drive through owing water.
4-25