Front brakes GMC SIERRA 2020 User Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 273
Warning (Continued)
.If the headlamps or
windshield are not cleaned
or in proper condition.
Be ready to take action and apply
the brakes. For more information,
see Defensive Driving 0187.
Keep the windshield, headlamps,
and FPB sensor clean and in
good repair.
FPB can be set to Off, Alert, or Alert
and Brake through vehicle
personalization. See “Collision/
Detection Systems” underVehicle
Personalization 0157.
Detecting the Pedestrian
Ahead
FPB alerts and automatic braking
will not occur unless the FPB
system detects a pedestrian. When
a nearby pedestrian is detected in
front of the vehicle, the pedestrian
ahead indicator will display amber.
Front Pedestrian Alert
With Head-Up Display
Without Head-Up Display
When the vehicle approaches a
pedestrian ahead too rapidly, the
red FPB alert display will flash on
the windshield. Eight rapid
high-pitched beeps will sound from
the front, or both sides of the Safety
Alert Seat will pulse five times. When this Pedestrian Alert occurs,
the brake system may prepare for
driver braking to occur more rapidly
which can cause a brief, mild
deceleration. Continue to apply the
brake pedal as needed. Cruise
control may be disengaged when
the Front Pedestrian Alert occurs.
Automatic Braking
If FPB detects it is about to crash
into a pedestrian ahead, and the
brakes have not been applied, FPB
may automatically brake moderately
or brake hard. This can help to
avoid some very low speed
pedestrian crashes or reduce
pedestrian injury. FPB can
automatically brake to detected
pedestrians between 8 km/h (5 mph)
and 80 km/h (50 mph). Automatic
braking levels may be reduced
under certain conditions, such as
higher speeds.
If this happens, Automatic Braking
may engage the Electric Parking
Brake (EPB) to hold the vehicle at a
stop. Release the EPB. A firm press

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
288 Driving and Operating
.Vehicles can tow in D (Drive).
Tow/Haul Mode is recommended
for heavier trailers. See Tow/
Haul Mode 0226. If the
transmission downshifts too
often, a lower gear may be
selected using Manual Mode.
See Manual Mode 0224.
If equipped, the following driver
assistance features should be
turned off when towing a trailer:
. Adaptive Cruise Control (ACC)
. Super Cruise Control
. Lane Keep Assist (LKA)
. Park Assist
. Automatic Parking Assist (APA)
. Reverse Automatic
Braking (RAB)
If equipped, the following driver
assistance features should be
turned to alert or off when towing a
trailer:
. Automatic Emergency
Braking (AEB)
. Intelligent Brake Assist (IBA) .
Front Pedestrian Braking (FPB)
If equipped with Lane Change Alert
(LCA), the LCA detection zones that
extend back from the side of the
vehicle do not move further back
when a trailer is towed. Use caution
while changing lanes when towing a
trailer.
If equipped with Rear Cross Traffic
Alert (RCTA), use caution while
backing up when towing a trailer, as
the RCTA detection zones that
extend out from the back of the
vehicle do not move further back
when a trailer is towed.
{Warning
To prevent serious injury or death
from carbon monoxide (CO),
when towing a trailer: . Do not drive with the
liftgate, trunk/hatch,
or rear-most window open.
(Continued)
Warning (Continued)
.Fully open the air outlets on
or under the instrument
panel.
. Adjust the climate control
system to a setting that
brings in only outside air.
See “Climate Control
Systems” in the Index.
For more information about
carbon monoxide, see Engine
Exhaust 0220.
Towing a trailer requires experience.
The combination of the vehicle and
trailer is longer and not as
responsive as the vehicle itself. Get
used to the handling and braking of
the combination by driving on a
level road surface before driving on
public roads.
The trailer structure, the tires, and
the brakes must all be rated to carry
the intended cargo. Inadequate
trailer equipment can cause the
combination to operate in an

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 291
Warning (Continued)
provide a means of escape
in the unlikely event the
vehicle slides into the water.
. If the boat launch surface is
slippery, have the driver
remain in the vehicle with
the brake pedal applied
while the boat is being
launched. The boat launch
can be especially slippery at
low tide when part of the
ramp was previously
submerged at high tide. Do
not back onto the ramp to
launch the boat if you are
not sure the vehicle can
maintain traction.
. Do not move the vehicle if
someone is in the path of
the trailer. Some parts of the
trailer might be underwater
and not visible to people
who are assisting in
launching the boat. Disconnect the wiring to the trailer
before backing the trailer into the
water to prevent damage to the
electrical circuits on the trailer.
Reconnect the wiring to the trailer
after removing the trailer from the
water. If the trailer has electric
brakes that can function when the
trailer is submerged, it might help to
leave the electrical trailer connector
attached to maintain trailer brake
functionality while on the boat ramp.
To back the trailer into the water:
1. If equipped, place the vehicle in four-wheel-drive high.
2. Slowly back down the boat ramp until the boat is floating,
but no further than necessary.
3. Press and hold the brake pedal, but do not shift into
P (Park) yet.
4. Have someone place chocks under the front wheels of the
vehicle.
5. Gradually release the brake pedal to allow the chocks to
absorb the load of the trailer. 6. Reapply the brake pedal. Then
apply the parking brake and
shift into P (Park).
7. Release the brake pedal.
Pulling the Trailer from the Water
To pull the trailer out of the water: 1. Press and hold the brake pedal.
2. Start the engine and shift into gear.
3. Release the parking brake.
4. Let up on the brake pedal.
5. Drive slowly until the tires are clear of the chocks.
6. Stop and have someone pick up and store the chocks.
7. Slowly pull the trailer from the water.
8. Once the vehicle and trailer have been driven from the
sloped part of the boat ramp,
the vehicle can be shifted from
four-wheel-drive high. Shift into

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 325
(W x (A + W.B.)) /W.B.= Weight the
accessory is adding to the
front axle.
Where:W = Weight of added accessory
A = Distance that the accessory
is in front of the front axle
W.B. = Vehicle Wheelbase
For example, adding a 318 kg
(700 lb) snow plow actually adds
more than 318 kg (700 lb) to the
front axle. Using the formula, if the
snow plow is 122 cm (4 ft) in front of
the front axle and the wheelbase is
305 cm (10 ft), then: W = 318 kg (700 lb)
A = 122 cm (4 ft) W.B. = 305 cm (10 ft)
(W x (A + W.B.)/W.B. =
(318 x (122 + 305))/305 = 445 kg
(980 lb)
This means if the front axle reserve
capacity is more than 445 kg
(980 lb), the snow plow could be
added without exceeding the
front GAWR.
Heavier equipment can be added on
the front of the vehicle if less cargo
or fewer passengers are carried,
or by positioning cargo toward the
rear. This reduces the load on the
front. However, the front GAWR,
rear GAWR, and Gross Vehicle
Weight Rating (GVWR) must never
be exceeded.
{Warning
On some vehicles that have
certain front mounted equipment,
such as a snow plow, it may be
possible to load the front axle to
the front Gross Axle Weight
Rating (GAWR) but not have (Continued)
Warning (Continued)
enough weight on the rear axle to
have proper braking performance.
If the brakes cannot work
properly, the vehice could crash.
Always follow the snow plow
manufacturer or installer's
recommendation for rear ballast
to ensure a proper front and rear
weight distribution ratio.
Maintaining a proper front and
rear weight distribution ratio is
necessary to provide proper
braking performance.
Total vehicle reserve capacity is the
difference between the GVWR and
the weight of the truck with full fuel
and passengers. It is the amount of
weight that can be added to the
vehicle before reaching the GVWR.
Reserve capacity numbers are
intended as a guide when selecting
the amount of equipment or cargo
the truck can carry. If unsure of the
vehicle's front, rear, or total weight,

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Vehicle Care 327
Vehicle Care
General Information
General Information . . . . . . . . . . 328
California Proposition65 Warning . . . . . . . . . . . . . . . . . 329
California Perchlorate Materials Requirements . . . . . 329
Accessories and Modifications . . . . . . . . . . . . . . . . 329
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 330
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 330
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 332
Engine Oil . . . . . . . . . . . . . . . . . . . . 339
Engine Oil Life System . . . . . . . 341
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 343
Engine Air Filter Life System . . . . . . . . . . . . . . . . . . . . . . 343
Engine Air Cleaner/Filter . . . . . . 344
Cooling System . . . . . . . . . . . . . . 346
Engine Overheating . . . . . . . . . . 351
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . 352
Engine Fan . . . . . . . . . . . . . . . . . . . 353 Power Steering Fluid . . . . . . . . . 354
Washer Fluid . . . . . . . . . . . . . . . . . 354
Brakes . . . . . . . . . . . . . . . . . . . . . . . 355
Brake Pad Life System . . . . . . . 356
Brake Fluid . . . . . . . . . . . . . . . . . . . 357
Battery - North America . . . . . . 358
Four-Wheel Drive . . . . . . . . . . . . . 361
Front Axle . . . . . . . . . . . . . . . . . . . . 361
Rear Axle . . . . . . . . . . . . . . . . . . . . 362
Noise Control System . . . . . . . . 362
Starter Switch Check . . . . . . . . . 363
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 363
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 363
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 364
Wiper Blade Replacement . . . . 364
Windshield Replacement . . . . . 365
Gas Strut(s) . . . . . . . . . . . . . . . . . . 365
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 366
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 367
Halogen Bulbs . . . . . . . . . . . . . . . . 367
LED Lighting . . . . . . . . . . . . . . . . . 367 Headlamps, Front Turn Signal,
Sidemarker, and Parking
Lamps . . . . . . . . . . . . . . . . . . . . . . 367
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 368
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 369
License Plate Lamp . . . . . . . . . . 369
Electrical System
Electrical System Overload . . . 370
Fuses and Circuit Breakers . . . 370
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 371
Instrument Panel Fuse
Block (Left) . . . . . . . . . . . . . . . . . 374
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 376
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 379
All-Season Tires . . . . . . . . . . . . . . 379
Winter Tires . . . . . . . . . . . . . . . . . . 380
Low-Profile Tires . . . . . . . . . . . . . 380
All-Terrain Tires . . . . . . . . . . . . . . . 381
Tire Sidewall Labeling . . . . . . . . 381
Tire Designations . . . . . . . . . . . . . 383
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 385

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
356 Vehicle Care
Caution
Continuing to drive with worn-out
brake pads could result in costly
brake repair.
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications in Capacities and
Specifications 0459.
Brake linings should always be
replaced as complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal
does not return to normal height,
or if there is a rapid increase in
pedal travel. This could be a sign
that brake service may be required.
Replacing Brake System Parts
Always replace brake system parts
with new, approved replacement
parts. If this is not done, the brakes
may not work properly. The braking
performance expected can change
in many other ways if the wrong
replacement brake parts are
installed or parts are improperly
installed.
Brake Pad Life System
When to Change Brake Pads
This vehicle has a system that
estimates the remaining life of the
front and rear brake pads. Brake
pad life is displayed in the Driver
Information Center (DIC), along with
a percentage for each axle. The
system must be reset every time the
brake pads are changed.
When the system has determined
that the brake pads need to be
replaced, a message will display,
which may include mileage
remaining. Brake pads should always be
replaced as complete axle sets.
How to Reset the Brake Pad
Life System
The system will automatically detect
when significantly worn brake pads
are replaced. When the ignition is
turned on after new pads and wear
sensors are installed, a message
will display. Follow the prompts to
reset the system.
The brake pad life system can also
be manually reset:
1. Display Brake Pad Life on the DIC. See Driver Information
Center (DIC) (Base Level)
0 148 or
Driver Information Center (DIC)
(Midlevel and Uplevel) 0149.
2. Press the thumbwheel or the trip odometer reset stem if the
vehicle does not have DIC
buttons. Select front or rear
pads as appropriate.
3. Select YES on the confirmation message, or press the trip
odometer reset stem on a base

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Vehicle Care 357
level DIC. Repeat for pads on
the other axle if they were also
replaced.
How to Disable the Brake Pad
Life System
The brake pad life system can be
turned off. This may be necessary if
aftermarket brake pads without wear
sensors are installed. When the
system is turned off, the front and
rear brake pad life percentages will
not display. However, the built-in
wear indicators that make a
high-pitched warning sound when
the brake pads are worn can still
determine when the pads should be
replaced. SeeBrakes0355.
To turn off the brake pad life system: 1. Display Brake Pad Life on the DIC. See Driver Information
Center (DIC) (Base Level)
0 148 or
Driver Information Center (DIC)
(Midlevel and Uplevel) 0149.
2. Select DISABLE. To turn the brake pad life system
back on, follow the above steps but
select ENABLE in Step 2.
Brake Fluid
The brake master cylinder reservoir
is filled with GM approved DOT 4
(1500) or DOT 3 (2500/3500) brake
fluid as indicated on the reservoir
cap. See
Engine Compartment
Overview 0332 for the location of
the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a
level surface, the brake fluid level
should be between the minimum
and maximum marks on the brake
fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down: .
Normal brake lining wear. When
new linings are installed, the
fluid level goes back up.
. A fluid leak in the brake
hydraulic system. Have the
brake hydraulic system fixed.
With a leak, the brakes will not
work well.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it.
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove fluid, as
necessary, only when work is done
on the brake hydraulic system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged. (Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
Index 489
Assistance Program,Roadside . . . . . . . . . . . . . . . . . . . . . . 467
Assistance Systems for Driving . . . . . . . . . . . . . . . . . . . . . . . . 268
Assistance Systems for Parking and Backing . . . . . . . . . . 257
Auto Stop
Stop/Start System . . . . . . . . . . . . 213
Automatic Dimming Mirrors . . . . . . . . . . . . . . . . 44
Door Locks . . . . . . . . . . . . . . . . . . . . . 26
Emergency Braking (AEB) . . . . 270
Headlamp System . . . . . . . . . . . . 168
Transmission . . . . . . . . . . . . . . . . . 221
Transmission Fluid . . . . . . . . . . . 343
Automatic Transmission
Manual Mode . . . . . . . . . . . . . . . . . 224
Shift Lock Control FunctionCheck . . . . . . . . . . . . . . . . . . . . . . . 363
Axle, Front . . . . . . . . . . . . . . . . . . . . . . 361
Axle, Rear . . . . . . . . . . . . . . . . . . . . . . 362
B
Battery Exterior Lighting BatterySaver . . . . . . . . . . . . . . . . . . . . . . . 174
Load Management . . . . . . . . . . . . 174 Battery (cont'd)
Power Protection . . . . . . . . . . . . . 174
Battery - North America . . . . 358, 419
Blade Replacement, Wiper . . . . . 364
Blind Spot Mirrors . . . . . . . . . . . . . . . 44
Brake Electric Boost . . . . . . . . . . . . . . . . . 232
Parking, Electric . . . . . . . . . . . . . . 233
System Warning Light . . . . . . . . 140
Brake Pad Life System . . . . . . . . . 356
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . 355 Antilock . . . . . . . . . . . . . . . . . . . . . . . 232
Assist . . . . . . . . . . . . . . . . . . . . . . . . . 234
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 357
Pad Life System . . . . . . . . . . . . . . 356
Braking . . . . . . . . . . . . . . . . . . . . . . . . . 188 AutomaticEmergency (AEB) . . . . . . . . . . . 270
Braking System Front Pedestrian (FPB) . . . . . . . 272
Break-In, New Vehicle . . . . . . . . . . 208
Bulb Replacement Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 369
Halogen Bulbs . . . . . . . . . . . . . . . . 367
Headlamp Aiming . . . . . . . . . . . . . 366
Headlamps . . . . . . . . . . . . . . . . . . . 367 Bulb Replacement (cont'd)
Headlamps, Front Turn
Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . . . 367
License Plate Lamps . . . . . . . . . 369
Taillamps, Turn Signal, Stoplamps, and Back-up
Lamps . . . . . . . . . . . . . . . . . . . . . . 368
Buying New Tires . . . . . . . . . . . . . . . 399
C
Calibration . . . . . . . . . . . . . . . . . . . . . . 121
California Perchlorate Materials
Requirements . . . . . . . . . . . . . . . 329
California Proposition
65 Warning . . . . . . . . . .329, 358, 419, Back Cover
Canadian Vehicle Owners . . . . . . . . 2
Capacities and Specifications . . . . . . . . . . . . . . . . . 459
Carbon Monoxide Engine Exhaust . . . . . . . . . . . . . . . 220
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . 28
Winter Driving . . . . . . . . . . . . . . . . 197
Cargo Tie-Downs . . . . . . . . . . . . . . . . . . . . .116

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