2020 GMC SIERRA fog light

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
174 Lighting
The exterior lamps and dome lamp
remain on for a set amount of time,
then automatically turn off.
The exterior lamps turn off
immediately by turning the exterior
lamp control off.
This feature can be changed. See
Vehicle Personalization0157.
Battery Load
Management
The vehicle has Electric Power
Management (EPM), which
estimates the battery's temperature
and state of charge. It then adjusts
the voltage for best performance
and extended life of the battery.
When the battery's state of charge
is low, the voltage is raised slightly
to quickly bring the charge back up.
When the state of charge is high,
the voltage is lowered slightly to
prevent overcharging. The voltmeter
gauge or the voltage display on the
Driver Information Center (DIC),
if equipped, may show the voltage moving up or down. This is normal.
If there is a problem, an alert will be
displayed.
The battery can be discharged at
idle if the electrical loads are very
high. This is true for all vehicles.
This is because the generator
(alternator) may not be spinning fast
enough at idle to produce all the
power that is needed for very high
electrical loads.
A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog
lamps, rear window defogger,
climate control fan at high speed,
heated seats, engine cooling fans,
trailer loads, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does this
by balancing the generator's output
and the vehicle's electrical needs.
It can increase engine idle speed to
generate more power, whenever
needed. It can temporarily reduce
the power demands of some
accessories.Normally, these actions occur in
steps or levels, without being
noticeable. In rare cases at the
highest levels of corrective action,
this action may be noticeable to the
driver. If so, a DIC message might
be displayed and it is recommended
that the driver reduce the electrical
loads as much as possible.
Battery Power Protection
This feature shuts off the dome and
reading lamps, if they are left on for
more than 10 minutes after the
ignition is turned off. The cargo
lamp shuts off after 20 minutes. This
prevents the battery from
running down.
Exterior Lighting Battery
Saver
The exterior lamps turn off about
10 minutes after the ignition is
turned off, if the parking lamps or
headlamps have been manually left
on. This protects against draining
the battery. To restart the 10-minute

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
178 Climate Controls
Air Delivery Mode Controls :
Press
z,Y, or[to change the
direction of the airflow. Any
combination of the three controls
can be selected. An indicator light
comes on in the selected mode
button.
To change the current mode, select
one or more of the following. An
indicator light will illuminate:
z: Air is directed to the
windshield, outboard a/c outlets,
and side window outlets.
Y: Air is directed to the a/c outlets.
[:Air is directed to the floor
outlets, with some air directed to the
windshield, outboard a/c outlets,
and side window outlets.
0MAX : Air is directed to the
windshield and the fan runs at a
higher speed if not already above a
medium fan speed. This mode
overrides the previous mode
selected and clears fog or frost from
the windshield more quickly. When the control is pressed again, the
system returns to the previous mode
setting and fan speed.
For best results, clear all snow and
ice from the windshield before
defrosting.
@:
Press to turn on recirculation.
An indicator light comes on. Air is
recirculated to quickly cool the
inside of the vehicle. It can also be
used to help reduce outside air and
odors that enter the vehicle.
Avoid using recirculation for long
periods of time in cold or damp
conditions. Using recirculation in
cold or damp conditions can result
in window fogging.
A/C : Press to turn the air
conditioning on or off. An indicator
light comes on to show that the air
conditioning is enabled. If the fan is
turned off, the air conditioner will not
run. The A/C light will stay on even
if the outside temperatures are
below freezing.
Rear Window Defogger
1REAR : If equipped, press to
turn the rear window defogger on or
off. An indicator light on the button
comes on to show that the rear
window defogger is on.
The rear window defogger only
works when the engine is running.
The defogger turns off if the ignition
is turned off or to ACC/
ACCESSORY.
If equipped with heated outside
mirrors, press
fto turn them on or
off. See Heated Mirrors 044.
Caution
Using a razor blade or sharp
object to clear the inside rear
window can damage the rear
window defogger. Repairs would
not be covered by the vehicle
warranty. Do not clear the inside
rear window with sharp objects.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Climate Controls 181
or passenger side temperature
display shows the temperature
setting increasing or decreasing.
SYNC :Press to link the passenger
temperature setting to the driver
setting. The SYNC indicator light will
turn on. When the passenger setting
is adjusted, the SYNC indicator light
will turn off.
Air Delivery Mode Control : Press
z,Y, or[to change the
direction of the airflow. Any
combination of the three controls
can be selected. An indicator light
comes on in the selected mode
button.
Changing the mode cancels the
automatic operation and the system
goes into manual mode. Press
AUTO to return to automatic
operation.
To change the current mode, select
one or more of the following:
z: Air is directed to the
windshield, outboard a/c outlets,
and side window outlets.
Y: Air is directed to the a/c outlets.
[:Air is directed to the floor
outlets, with some air directed to the
windshield, outboard a/c outlets,
and side window outlets.
0MAX : Air is directed to the
windshield and the fan runs at a
higher speed if not already above a
medium fan speed. This mode
overrides the previous mode
selected and clears fog or frost from
the windshield more quickly. When
the control is pressed again, the
system returns to the previous mode
setting and fan speed.
For best results, clear all snow and
ice from the windshield before
defrosting.
@: Press to turn on recirculation.
An indicator light comes on. Air is
recirculated to quickly cool the
inside of the vehicle. It can also be
used to help reduce outside air and
odors that enter the vehicle. Avoid using recirculation for long
periods of time in cold or damp
conditions. Using recirculation in
cold or damp conditions can result
in window fogging.
A/C :
Press to turn the air
conditioning on or off. An indicator
light comes on to show that the air
conditioning is enabled. If the fan is
turned off, the air conditioner will not
run. The A/C light will stay on even
if the outside temperatures are
below freezing.
Rear Window Defogger
1REAR : If equipped, press to
turn the rear window defogger on or
off. An indicator light on the button
comes on to show that the rear
window defogger is on.
The rear window defogger only
works when the engine is running.
The defogger turns off if the ignition
is turned off or to ACC/
ACCESSORY.
If equipped with heated outside
mirrors, press
fto turn them on or
off. See Heated Mirrors 044.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
254 Driving and Operating
Other Vehicle Lane Changes
ACC will not detect a vehicle ahead
until it is completely in the lane. The
brakes may need to be manually
applied.
Objects Not Directly in Front of
Your Vehicle
The detection of objects in front of
the vehicle may not be possible if:
.The vehicle or object ahead is
not within your lane.
. The vehicle ahead is shifted, not
centered, or is shifted to one
side of the lane. Driving in Narrow Lanes
Vehicles in adjacent traffic lanes or
roadside objects may be incorrectly
detected when located along the
roadway.
Do Not Use ACC on Hills and
When Towing a Trailer
Do not use ACC when driving on
steep hills or when towing a trailer.
ACC will not detect a vehicle in the
lane while driving on steep hills.
If the brakes are applied, ACC
disengages.
Disengaging ACC
There are three ways to
disengage ACC:
.
Step lightly on the brake pedal. .
Press
*.
. Press
J.
Erasing Speed Memory
The ACC set speed is erased from
memory if
Jis pressed or if the
ignition is turned off.
Weather Conditions Affecting ACC
If the interior temperature is
extremely high, the instrument
cluster may indicate that ACC is
temporarily unavailable. This can be
caused by extreme hot weather
conditions with direct sunlight on the
front camera. ACC will return to
normal operation once the cabin
temperature is lower.
Conditions that are associated with
low visibility, such as fog, rain,
snow, or road spray, may limit ACC
performance. Water droplets from
rain or snow that remain on the
windshield may also limit ACC’s
ability to detect objects.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 255
Lighting Conditions Affecting ACC
The ACC front camera can be
affected by poor lighting conditions,
and ACC may have limited
performance when:
.There are changes in brightness,
such as entering and exiting
tunnels, bridges, and
overpasses.
. Low sun angles cause the
camera to not detect objects,
or it is more difficult to detect
objects in the same traffic lane.
. Lighting is poor in the evening or
early morning
. There are multiple changes in
brightness or shadows along the
vehicle roadway.
. In a tunnel without the
headlamps on, or in a tunnel
when there is a vehicle in front
that does not have its
taillamps on. .
Subjected to strong light from
opposing lane traffic in the front
of the vehicle, such as
high-beam headlamps from
oncoming traffic.
Accessory Installations and
Vehicle Modifications
Do not install or place any object
around the front camera windshield
area that would obstruct the front
camera view.
Do not install objects on top of the
vehicle that overhang and obstruct
the front camera, such as a canoe,
kayak, or other items that can be
transported on the vehicle roof.
Do not modify the hood, headlamps,
or fog lamps, as this may limit the
camera’s ability to detect an object.
Cleaning the Sensing System
The camera sensor on the
windshield behind the rearview
mirror can become blocked by
snow, ice, dirt, mud, or debris. This
area needs to be cleaned for ACC
to operate properly. The vehicle headlamps may need to
be cleaned due to dirt, snow, or ice.
Objects that are not illuminated
correctly may be difficult to detect.
If ACC will not operate, regular
cruise control may be available. See
“Switching Between ACC and
Regular Cruise Control”
previously
in this section. Always consider
driving conditions before using
either cruise control system.
For cleaning instructions, see
“Washing the Vehicle” under
Exterior Care 0429.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
436 Vehicle Care
Caution
To prevent scratching, never use
abrasive cleaners on automotive
glass. Abrasive cleaners or
aggressive cleaning may damage
the rear window defogger.
Cleaning the windshield with water
during the first three to six months
of ownership will reduce tendency
to fog.
Speaker Covers
Vacuum around a speaker cover
gently, so that the speaker will not
be damaged. Clean spots with water
and mild soap.
Coated Moldings
Coated moldings should be cleaned.
. When lightly soiled, wipe with a
sponge or soft, lint-free cloth
dampened with water.
. When heavily soiled, use warm
soapy water.
Fabric/Carpet/Suede
Start by vacuuming the surface
using a soft brush attachment. If a
rotating vacuum brush attachment is
being used, only use it on the floor
carpet. Before cleaning, gently
remove as much of the soil as
possible:
.Gently blot liquids with a paper
towel. Continue blotting until no
more soil can be removed.
. For solid soils, remove as much
as possible prior to vacuuming.
To clean: 1. Saturate a clean, lint-free colorfast cloth with water.
Microfiber cloth is
recommended to prevent lint
transfer to the fabric or carpet.
2. Remove excess moisture by gently wringing until water does
not drip from the cleaning cloth.
3. Start on the outside edge of the soil and gently rub toward the
center. Fold the cleaning cloth to a clean area frequently to
prevent forcing the soil in to the
fabric.
4. Continue gently rubbing the soiled area until there is no
longer any color transfer from
the soil to the cleaning cloth.
5. If the soil is not completely removed, use a mild soap
solution followed only by plain
water.
If the soil is not completely
removed, it may be necessary to
use a commercial upholstery
cleaner or spot lifter. Test a small
hidden area for colorfastness before
using a commercial upholstery
cleaner or spot lifter. If ring
formation occurs, clean the entire
fabric or carpet.
After cleaning use a paper towel to
blot excess moisture.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
492 Index
Extender, Seat Belt . . . . . . . . . . . . . . 71
Exterior Cargo Lamps . . . . . . . . . . 171
Exterior Lamp Controls . . . . . . . . . 165
Exterior Lamps Off Reminder . . . 167
Exterior Lighting BatterySaver . . . . . . . . . . . . . . . . . . . . . . . . . 174
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . . . 353
Filter, Engine Air Cleaner . . . . . . . . . . . 344
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 168
Flashers, Hazard Warning . . . . . . 169
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . 405 Changing . . . . . . . . . . . . . . . . . . . . . 407
FlexFuel
E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Floor Console Storage . . . . . . . . . . 115
Floor Mats . . . . . . . . . . . . . . . . . . . . . . 438
Fluid Automatic Transmission . . . . . . 343
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 357
Four-Wheel DriveTransfer Case . . . . . . . . . . . . . . . 227
Power Steering . . . . . . . . . . . . . . . 354
Washer . . . . . . . . . . . . . . . . . . . . . . . 354
Fog Lamps . . . . . . . . . . . . . . . . . . . . . 170 Folding Mirrors . . . . . . . . . . . . . . . . . . 43
Forward Collision Alert
(FCA) System . . . . . . . . . . . . . . . . . 268
Four-Wheel Drive . . . . . . . . . . 227, 361
Four-Wheel-Drive Light . . . . . . . . . 142
Frequency Statement Radio . . . . . . . . . . . . . . . . . . . . . . . . . 472
Front Axle . . . . . . . . . . . . . . . . . . . . . . 361
Front Fog Lamp Light . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Front Pedestrian Braking
(FPB) System . . . . . . . . . . . . . . . . . 272
Front Seats Adjustment . . . . . . . . . . . . . . . . . . . . . 55
Heated and Ventilated . . . . . . . . . . 61
Fuel
Additives . . . . . . . . . . . . . . . . . . . . . 282
Economy, Driving for Better . . . 186
Filling a Portable FuelContainer . . . . . . . . . . . . . . . . . . . 286
Filling the Tank . . . . . . . . . . 283, 285
Foreign Countries . . . . . . . . . . . . 281
Gauge . . . . . . . . . . . . . . . . . . . . . . . . 132
Low Fuel Warning Light . . . . . . . 146
Management, Active . . . . . . . . . . 219
Prohibited Fuels . . . . . . . . . . . . . . 281
Recommended . . . . . . . . . . 280, 281
Top Tier . . . . . . . . . . . . . . . . . . . . . . 280 Full-Size Spare Tire . . . . . . . . . . . . 418
Fuses
Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . 371
Fuses and Circuit Breakers . . . 370
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . 374, 376G
Garage Door Opener . . . . . . . . . . . 161
Programming . . . . . . . . . . . . . . . . . 161
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . 365
Gauges
Engine CoolantTemperature . . . . . . . . . . . . . . . . 134
Engine Oil Pressure . . . . . . . . . . 133
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Odometer . . . . . . . . . . . . . . . . . . . . . 132
Speedometer . . . . . . . . . . . . . . . . . 131
Tachometer . . . . . . . . . . . . . . . . . . . 132
Trip Odometer . . . . . . . . . . . . . . . . 132
Voltmeter . . . . . . . . . . . . . . . . . . . . . 135
Warning Lights and Indicators . . . . . . . . . . . . . . . . . . . 126
General Information Service and Maintenance . . . . . 440
Towing . . . . . . . . . . . . . . . . . . . . . . . . 287
Vehicle Care . . . . . . . . . . . . . . . . . . 328

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
494 Index
Lamps (cont'd)On Reminder . . . . . . . . . . . . . . . . . 147
Reading . . . . . . . . . . . . . . . . . . . . . . 173
Lane Change Alert (LCA) . . . . . . . 274
Lane Departure
Warning (LDW) . . . . . . . . . . . . . . . . 276
Lane Departure Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Lane Keep Assist (LKA) . . . . . . . . 278
Lane Keep Assist Light . . . . . . . . . 143
Lap-Shoulder Belt . . . . . . . . . . . . . . . 68
LATCH System
Replacing Parts after aCrash . . . . . . . . . . . . . . . . . . . . . . . 105
LATCH, Lower Anchors and Tethers for Children . . . . . . . . . . . . 92
LED Lighting . . . . . . . . . . . . . . . . . . . . 367
Lighting Entry . . . . . . . . . . . . . . . . . . . . . . . . . 173
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
Illumination Control . . . . . . . . . . . 172
LED . . . . . . . . . . . . . . . . . . . . . . . . . . 367
Task . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Lights Airbag Readiness . . . . . . . . . . . . . 136
Antilock Brake System(ABS) Warning . . . . . . . . . . . . . . 141
Brake System Warning . . . . . . . 140 Lights (cont'd)
Charging System . . . . . . . . . . . . . 138
Check Engine (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 138
Cruise Control . . . . . . . . . . . . . . . . 147
Door Ajar . . . . . . . . . . . . . . . . . . . . . 148
Driver Mode Control . . . . . . . . . . 145
Electric Parking Brake . . . . . . . . 141
Electronic Stability Control (ESC), Off . . . . . . . . . . . . . . . . . . . 144
Engine Coolant Temperature Warning . . . . . . . 145
Engine Oil Pressure . . . . . . . . . . 146
Flash-to-Pass . . . . . . . . . . . . . . . . . 168
Four-Wheel-Drive . . . . . . . . . . . . . 142
Front Fog Lamp . . . . . . . . . . . . . . 147
High-Beam On . . . . . . . . . . . . . . . . 147
High/Low Beam Changer . . . . . 167
Hill Descent Control . . . . . . . . . . 142
Lane Departure Warning . . . . . . 142
Lane Keep Assist . . . . . . . . . . . . . 143
Low Fuel Warning . . . . . . . . . . . . 146
Seat Belt Reminders . . . . . . . . . . 136
Security . . . . . . . . . . . . . . . . . . . . . . 147
Service Electric Parking Brake . . . . . . . . . . . . . . . . . . . . . . . 141
Tire Pressure . . . . . . . . . . . . . . . . . 145
Tow/Haul Mode . . . . . . . . . . . . . . . 142 Lights (cont'd)
Traction Off . . . . . . . . . . . . . . . . . . . 143
Limited-Slip Differential . . . . . . . . . 242
Lock Steering Column . . . . . . . . . . . . . . . . 38
Locking Rear Axle . . . . . . . . . . . . . . 243
Locks Automatic Door . . . . . . . . . . . . . . . . . 26
Delayed Locking . . . . . . . . . . . . . . . . 26
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Lockout Protection . . . . . . . . . . . . . . 27
Power Door . . . . . . . . . . . . . . . . . . . . . 26
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Loss of Control . . . . . . . . . . . . . . . . . 190
Low Fuel Warning Light . . . . . . . . . 146
Low-Profile Tires . . . . . . . . . . . . . . . . 380
Lower Anchors and Tethers for Children (LATCH
System) . . . . . . . . . . . . . . . . . . . . . . . . 92
Lumbar Adjustment . . . . . . . . . . . . . . 57 Front Seats . . . . . . . . . . . . . . . . . . . . . 57
M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . . . 457
Maintenance and Care Additional . . . . . . . . . . . . . . . . . . . . . 450
Maintenance Schedule . . . . . . . . . 442