towing GMC SIERRA DENALI 2020 Owner's Guide
[x] Cancel search | Manufacturer: GMC, Model Year: 2020, Model line: SIERRA DENALI, Model: GMC SIERRA DENALI 2020Pages: 501, PDF Size: 7.61 MB
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290 Driving and Operating
The vehicle can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts too
often under heavy loads and/or hilly
conditions.
When towing at higher altitudes,
engine coolant will boil at a lower
temperature than at lower altitudes.
If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle could show signs similar to
engine overheating. To avoid this,
let the engine run, preferably on
level ground, with the transmission
in P (Park) for a few minutes before
turning the engine off. If the
overheat warning comes on, see
Engine Overheating0351.
Viewing Systems
If equipped, the viewing systems on
the vehicle can improve visibility
while hitching, backing, and driving
with a trailer. See Driver Assistance
Systems 0255.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and
trailer on a level surface when
possible.
When parking your vehicle and your
trailer on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into the curb if
facing downhill or into traffic if
facing uphill.
2. Have someone place chocks under the trailer wheels.
3. Gradually release the brake pedal to allow the chocks to
absorb the load of the trailer.
4. Reapply the brake pedal. Then apply the parking brake and
shift into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
.Start the engine.
. Shift into a gear.
. Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Launching and Retrieving
a Boat
Backing the Trailer into the Water
{Warning
.Have all passengers get out
of the vehicle before
backing onto the sloped part
of the ramp. Lower the
driver and passenger side
windows before backing
onto the ramp. This will
(Continued)
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292 Driving and Operating
the drive mode that is
appropriate for the road
conditions.
Caution
If the vehicle tires begin to spin
and the vehicle begins to slide
toward the water, remove your
foot from the accelerator pedal
and apply the brake pedal. Seek
help to have the vehicle towed up
the ramp.
Maintenance when Trailer
Towing
The vehicle needs service more
often when used to tow trailers. See
Maintenance Schedule0441. It is
especially important to check the
engine oil, axle lubricant, belts,
cooling system, and brake system
before and during each trip.
Check periodically to see that all
nuts and bolts on the trailer hitch
are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See Engine Overheating
0 351.
Trailer Towing
If equipped with a diesel engine,
see the Duramax diesel
supplement.
Caution
Towing a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To tow a trailer
correctly, follow the directions in
this section and see your dealer
for important information about
towing a trailer with the vehicle.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy. Successful, safe trailering takes
correct equipment, and it has to be
used properly.
The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of
your passengers. Read this section
carefully before pulling a trailer.
Trailer Weight
{Warning
Never exceed the towing capacity
for your vehicle.
Safe trailering requires monitoring
the weight, speed, altitude, road
grades, outside temperature, and
how frequently the vehicle is used to
tow a trailer.
Trailer Weight Ratings
When towing a trailer, the combined
weight of the vehicle, vehicle
contents, trailer, and trailer contents
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must be below all of the maximum
weight ratings for the vehicle,
including:
.GCWR: Gross Combined Weight
Rating
. GVWR: Gross Vehicle Weight
Rating
. Maximum Trailer Weight Rating
. GAWR-RR: Gross Axle Weight
Rating-Rear
. Maximum Trailer Tongue Weight
Rating
See “Weight-Distributing Hitch and
Adjustment” underTowing
Equipment 0296 to determine if
equalizer bars are required to obtain
the maximum trailer weight rating.
See “Trailer Brakes” underTowing
Equipment 0296 to determine if
brakes are required based on your
trailer's weight.
The only way to be sure the weight
is not exceeding any of these
ratings is to weigh the tow vehicle
and trailer combination, fully loaded
for the trip, getting individual
weights for each of these items. A trailering information label on the
B-pillar shows tow rating information
for the vehicle.
{Warning
You and others could be seriously
injured or killed if the trailer is too
heavy or the trailer brakes are
inadequate for the load. The
vehicle may be damaged, and the
repairs would not be covered by
the vehicle warranty.
Only tow a trailer if all the steps in
this section have been followed.
Ask your dealer for advice and
information about towing a trailer.
Gross Combined Weight
Rating (GCWR)
GCWR is the total allowable weight
of the completely loaded vehicle
and trailer including any fuel,
passengers, cargo, equipment, and
accessories. Do not exceed the
GCWR for your vehicle. The GCWR
for the vehicle is on the Trailering
Information Label.
To check that the weight of the
vehicle and trailer are within the
GCWR for the vehicle, follow these
steps:
1. Start with the "curb weight" from the Trailering Information
Label.
2. Add the weight of the trailer loaded with cargo and ready
for the trip.
3. Add the weight of all passengers.
4. Add the weight of all cargo in the vehicle.
5. Add the weight of hitch hardware such as a draw bar,
ball, load equalizer bars,
or sway bars.
6. Add the weight of any accessories or aftermarket
equipment added to the
vehicle.
The resulting weight cannot exceed
the GCWR value on the Trailering
Information Label.
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half of the maximum allowable
tongue weight for the vehicle or
227 kg (500 lb), whichever is less.
Rear Gross Axle Weight Rating
(GAWR-RR)
The GAWR-RR is the total weight
that can be supported by the rear
axle of the vehicle. Do not exceed
the GAWR-RR for the vehicle, with
the tow vehicle and trailer fully
loaded for the trip including the
weight of the trailer tongue. If using
a weight-distributing hitch, do not
exceed the GAWR-RR before
applying the weight distribution
spring bars.
The GAWR-RR for the vehicle is on
the Trailering Information Label.
Ask your dealer for trailering
information or assistance.
Towing Equipment
Hitches
Conventional Hitch
A conventional hitch is bolted to the
frame or cross member of the tow
vehicle, and is generally rated Class
2, 3, or 4.Gooseneck Hitch
A gooseneck hitch is designed to be
coupled to a special hitch leveraging
a hitch ball, and is mounted over the
rear axle in the truck bed.
Fifth-Wheel Hitch
A fifth-wheel hitch is mounted over
the rear axle in the truck bed, and
leverages a hinged plate
—the
same type of hitch leveraged by
semi trucks. Generally, fifth-wheel
hitches accommodate large trailers
with as many as one, two, or three
axles.
Always use the correct hitch
equipment for your vehicle.
Crosswinds, large trucks going by,
and rough roads can affect the
trailer and the hitch.
Proper hitch equipment for your
vehicle helps maintain control of the
vehicle-trailer combination. Many
trailers can be towed using a
weight-carrying hitch which has a
coupler latched to the hitch ball, or a
tow eye latched to a pintle hook.
Other trailers may require a
weight-distributing hitch that uses
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spring bars to distribute the trailer
tongue weight between your vehicle
and trailer axles. Fifth-wheel and
gooseneck hitches may also be
used. See“Maximum Trailer Tongue
Weight ”under Trailer Towing 0292
for weight limits with various hitch
types.
Avoid sharp turns when using a
step-bumper hitch to prevent
damage. Make wider turns to
prevent contact between your trailer
and your bumper.
Consider using mechanical sway
controls with any trailer. Ask a
trailering professional about sway
controls or refer to the trailer
manufacturer's recommendations
and instructions.
Weight-Distributing Hitch and
Adjustment
A weight-distributing hitch may be
useful with some trailers. Use the
following guidelines to determine if a
weight-distributing hitch should
be used.
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Vehicle SeriesTrailer WeightWeight-Distributing Hitch
Usage Hitch Distribution
1500 Up to 3 175 kg (7,000 lb) Not Required 50%
1500 Over 3 175 kg (7,000 lb) Required50%
2500/3500 Up to 9 080 kg (20,000 lb) Not Required 25%
1. Front of Vehicle
2. H1/H2 Body to Ground
Distance
Towing with Model 1500 Trucks
1. Position the truck so that the trailer is ready to connect.
Keep the trailer detached.
2. Measure the height of the top of the front wheel opening at
the fender to the ground (H1).
3. Attach the vehicle to the trailer. Do not attach weight
distribution bars at this time.
4. Measure the height of the top of the front wheel opening on
the fender to the ground (H2). 5. Install and adjust the tension in
the weight-distributing bars per
the manufacturers’
recommendations so that the
height of the front fender is
approximately H2−[(H2−H1)/2]
(halfway between the two
measured ride heights).
6. Visually inspect the trailer and weight-distributing hitch to
ensure that the manufacturers’
recommendations have
been met.
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MeasurementHeight Example 1500 (mm)
H1 1 000
H2 1 050
H2−H1 50
(H2−H1)/2 25
H2−[(H2−H1)/2] 1 025
Towing with Model 2500/3500
Trucks 1. Position the truck so that the trailer is ready to connect.
Keep the trailer detached.
2. Measure the height of the top of the front wheel opening at
the fender to the ground (H1).
3. Attach the vehicle to the trailer. Do not attach weight
distribution bars at this time.
4. Measure the height of the top of the front wheel opening on
the fender to the ground (H2). 5. Install and adjust the tension in
the weight-distributing bars per
the manufacturers’
recommendations so that the
height of the front fender is
approximately H2−[(H2−H1)/4]
(1/4 the difference between the
two measured ride heights,
below the secondary ride
height {H2}).
6. Visually inspect the trailer and weight-distributing hitch to
ensure that the manufacturers’
recommendations have
been met.
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MeasurementHeight Example 2500/3500 (mm)
H1 1 040
H2 1 080
H2−H1 40
(H2−H1)/4 10
H2−[(H2−H1)/4] 1 070
Tires
.
Do not tow a trailer while using a
compact spare tire on the
vehicle.
. Tires must be properly inflated to
support loads while towing a
trailer. See Tires0379 for
instructions on proper tire
inflation.
Fifth-Wheel and Gooseneck
Trailering
Fifth-wheel and gooseneck trailers
can be used with many pickup
models. These trailers place a
larger percentage of the weight
(kingpin weight) on the tow vehicle
than conventional trailers. Make sure this weight does not cause the
vehicle to exceed GAWR or GVWR.
Fifth-wheel or gooseneck kingpin
weight should be 15–25% of the
trailer weight up to the maximum
amount specified in the trailering
chart for the vehicle. See
“Trailer
Weight" under Trailer Towing0292.
The hitch should be in the pickup
bed so that its centerline is over or
slightly in front of the rear axle. Take
care that it is not so far forward that
it will contact the back of the cab in
sharp turns. This is especially
important for short box pickups.
Trailer pin box extensions and
sliding fifth-wheel hitch assemblies
may be used. There should be at
least 15 cm (6 in) of clearance between the top of the pickup box
and the bottom of the trailer shelf
that extends over the box.
Make sure the hitch is attached to
the tow vehicle frame rails. Do not
use the pickup box for support.
Safety Chains
Always attach safety chains
between the vehicle and the trailer.
Instructions about safety chains
may be provided by the hitch
manufacturer or by the trailer
manufacturer.
If the trailer being towed weighs up
to 2 271 kg (5,000 lb) with a
factory-installed step bumper, safety
chains may be attached to the
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lamp circuits on the trailer. DIC
messages and Trailering App alerts
may be displayed if lighting circuit
issues are detected on the trailer.
Pressing START LIGHT TEST in the
Trailering App automatically
activates the trailer lamps. The
Trailering App is not a substitute for
manually inspecting your trailer
lamps. SeeTrailering App 0310.
Turn Signals When Towing a
Trailer
When properly connected, the trailer
turn signals will illuminate to indicate
the vehicle is turning, changing
lanes, or stopping. When towing a
trailer, the arrows on the instrument
cluster will illuminate even if the
trailer is not properly connected or
the bulbs are burned out.
Tow/Haul Mode
For instructions on how to enter
Tow/Haul Mode, see Driver Mode
Control 0238.
Tow/Haul assists when pulling a
heavy trailer or a large or heavy
load. See Tow/Haul Mode 0227. Tow/Haul Mode is designed to be
most effective when the vehicle and
trailer combined weight is at least
75% of the vehicle's Gross
Combined Weight Rating (GCWR).
See
“Trailer Weight ”under Trailer
Towing 0292.
Tow/Haul Mode is most useful when
towing a heavy trailer or carrying a
large or heavy load:
. Through rolling terrain.
. In stop-and-go traffic.
. In busy parking lots.
Operating the vehicle in Tow/Haul
Mode when lightly loaded or not
towing will not cause damage;
however, it is not recommended and
may result in unpleasant engine and
transmission driving characteristics,
heavy or light steering efforts, and
reduced fuel economy.Integrated Trailer Brake
Control System
The vehicle may have an Integrated
Trailer Brake Control (ITBC) system
for use with electric trailer brakes or
most electric over hydraulic trailer brake systems. These instructions
apply to both types of electric trailer
brakes.
This symbol is on the Trailer Brake
Control Panel on vehicles with an
ITBC system. The power output to
the trailer brakes is proportional to
the amount of vehicle braking. This
available power output to the trailer
brakes can be adjusted to a wide
range of trailering situations.
The ITBC system is integrated with
the vehicle’
s brake, antilock brake,
and StabiliTrak/Electronic Stability
Control (ESC) systems. In trailering
conditions that cause the vehicle’s
antilock brake or StabiliTrak/ESC
systems to activate, power sent to
the trailer's brakes will be
automatically adjusted to minimize
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.Activate the Manual Trailer
Brake Apply Lever
TRAILER GAIN: Press a Trailer
Gain button to recall the current
Trailer Gain setting. Each press and
release of the gain buttons will then
change the Trailer Gain setting.
Press the Trailer Gain (+) or (-) to
adjust. Press and hold to
continuously adjust the Trailer Gain.
To turn the output to the trailer off,
adjust the Trailer Gain setting to 0.0.
This setting can be adjusted from
0.0 to 10.0 with a trailer connected
or disconnected.
TRAILER OUTPUT: This displays
anytime a trailer with electric brakes
is connected. Output to the trailer
brakes is based on the amount of
vehicle braking present and relative
to the Trailer Gain setting. Output is
displayed from 0 to 100% for each
gain setting.
The Trailer Output will indicate “- - -
- - -” on the Trailer Brake Display
Page whenever the following occur:
. No trailer is connected. .
A trailer without electric brakes
is connected. No DIC message
displays.
. A trailer with electric brakes has
become disconnected.
A CHECK TRAILER WIRING
message displays on the DIC.
. There is a fault present in the
wiring to the trailer brakes.
A CHECK TRAILER WIRING
message displays on the DIC.
. The ITBC system is not working
due to a fault. A SERVICE
TRAILER BRAKE SYSTEM
message displays in the DIC.
Manual Trailer Brake Apply
Lever
Slide this lever right to apply the
trailer ’s electric brakes independent
of the vehicle’s brakes. Use this
lever to adjust the Trailer Gain to
achieve proper power output to the
trailer brakes. Under certain
circumstances, this lever can also
be used to apply additional trailer
braking. The trailer and vehicle
brake lamps will come on when either the vehicle brakes or trailer
brakes are applied and properly
connected.
Trailer Gain Adjustment
Procedure
Trailer Gain should be set for a
specific trailering condition and it
must be readjusted anytime vehicle
loading, trailer loading, or road
surface conditions change.
{Warning
Trailer brakes that are
over-gained or under-gained may
not stop the vehicle and the trailer
as intended and can result in a
crash. Always follow the
instructions to set the Trailer Gain
for the proper trailer stopping
performance.
To adjust Trailer Gain for each
towing condition: 1. Drive the vehicle with the trailer attached on a level road
surface representative of the