fuel GMC SIERRA 2024 Service Manual

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
Driving and Operating 281
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 must be below all of the
maximum weight ratings for the vehicle,
including:
.Gross Combined Weight Rating (GCWR)
.Gross Vehicle Weight Rating (GVWR)
.Maximum Trailer Weight Rating
.Gross Axle Weight Rating-Rear (GAWR-RR)
.Maximum Trailer Tongue Weight Rating
See “Weight-Distributing Hitch and
Adjustment” underTowing Equipment 0284
to determine if equalizer bars are required
to obtain the maximum trailer weight
rating. See
“Trailer Brakes” underTowing
Equipment 0284 to determine if brakes are
required based on the trailer 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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
Driving and Operating 291
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, seeDriver 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” underTrailer
Towing 0280.
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 trailer wheel lock-up.
This does not imply that the trailer has
StabiliTrak/ESC.
If the vehicle’s brake, antilock brake,
or StabiliTrak/ESC systems are not
functioning properly, the ITBC system may
not function fully or at all. Make sure all of
these systems are fully operational to allow
the ITBC system to function properly.
The ITBC system is powered through the
vehicle's electrical system. Turning the
ignition off will also turn off the ITBC
system. The ITBC system is fully functional
only when the ignition is in on.{Warning
Connecting a trailer that has an air brake
system may result in reduced or
complete loss of trailer braking, including
increased stopping distance or trailer
instability which could result in serious
(Continued)

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
300 Driving and Operating
If trailer dimensions are out of range, this
feature will be unavailable.
Status View
If a trailer is connected, the Status view
shows status information for the active
trailer profile.
If no trailer is connected, the Status view
shows the last trailer profile with a status of
Not Connected.
The Status view shows:
.Lights
.Tires
.Maintenance
.Cameras
.Checklists
.Weight
.Towing AssistScroll right or left to see more options.
Each section shows high level status
information for the feature. Selecting a
section will open up a new screen with
additional information and/or options.
Selecting a camera view will open up a new
screen to preview the camera image. The
status view displays mileage and fuel
economy information.
Lights
This view displays the names of the trailer
connector pins, a graphic of the trailer
connector, and a graphic of the back of the
trailer.
Any connector pin that failed will be amber
color, and the location of the corresponding
connection will be highlighted on the
graphic of the back of the trailer.
If a trailer connection is detected without
any faults, the view will display No Issues
Found.
When a trailer is connected, the Trailering
App detects the trailer connection using the
Stop/Turn Signal lighting circuits and alerts
the driver by requesting a trailer profile
setup through the Trailering App on the
infotainment screen. If a default trailer
profile is selected, the Trailering App will not
display a Trailer Detection Alert to the user
when a trailer is connected.
When a trailer is connected and the vehicle
is off, the Trailering App will periodically
pulse the lighting circuits of the trailer to
verify it is still connected. The trailer lights
may periodically flash as a result of this
trailer connection detection. These flashes
may be more visible in dark ambient light
environments. The flashing or flickering
lights are a normal condition and the
Trailering App has built-in protections to
prevent the battery from draining. When
Theft Alert is enabled, the frequency and
pattern of this flashing will change.
If a connected trailer becomes disconnected,
a message about the trailer disconnect will
appear on the Driver Information Center
(DIC) immediately (if vehicle is on) or the

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
Driving and Operating 303
Touch the box next to each item if that step
has been completed.
Touch
4to access a detailed view of each
step. Within each detailed view, touch Next
and Previous to navigate between steps.
Touch Clear All to clear the completed
statuses from all items in the current
checklist.
Custom Checklist Items
For each of the Trailer Profile checklists,
there is an option to create custom items to
view in the checklist. The custom item will
appear at the bottom of the checklist.
Guest Trailer and No Trailer Connected
If a Guest Trailer Profile is active, or if no
trailer is connected, the checklist will show
all of the checklists associated with Custom
Trailer Profiles in addition to default
checklist.
Weight
Touch to turn on or off the Gross Combined
Weight (GCW).
When on, an alert may be presented when
the combined weight of the vehicle and
trailer may exceed the vehicle’s Gross Combined Weight Rating (GCWR). For more
information on the GCW Alert, see
Trailer
Towing 0280.
Towing Assist
A trailer should be connected to complete
this portion of profile setup.
Touch to set up towing assist features for
the Trailer Profile. See "Towing Assist" for
details on the setup.
Guest Trailer Status View
If the Guest Trailer Profile is active, the
Status view shows:
.Lights
.Cameras
.Checklist
.Weight
Scroll right or left to see more options.
The Trailer Status view displays mileage and
fuel economy information. Mileage and fuel
economy will reset after the trailer
disconnects.
Accessory/No Trailer Status View
If the Accessory/No Trailer profile is active,
trailer status information is not available.
Trailers View
Touch the trailer profile icon/name in the
Status View to view, activate, create, edit,
or delete Trailer Profiles.
If a trailer is connected, touch the Trailer
Profile name to activate a Trailer Profile.
There can be up to five Custom Trailer
Profiles on the vehicle.
The Custom Trailer Profiles and Guest Trailer
are in order of the most frequently used.
The Accessory/No Trailer profile is shown
below the Custom Trailer Profiles and Guest
Trailer Profile.
Guest Trailer
If the Guest Trailer Profile is the active
Trailer Profile, trailer detection, lights/
connections status, theft, and the Tow/Haul
reminder alerts can be sent. The system will
not track total mileage or fuel economy, but
the system will track trip mileage and fuel
economy if the Guest Trailer Profile is active.
The TTPMS or maintenance reminders
cannot be set up for a Guest Trailer Profile.
The Guest Trailer Profile cannot be edited.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
304 Driving and Operating
Accessory/No Trailer
If the Accessory/No Trailer Profile is active,
alerts will not be sent and the system will
not track mileage or fuel economy. The
TTPMS or maintenance reminders cannot be
set up for the Accessory/No Trailer Profile.
The Accessory/No Trailer profile cannot be
edited.
No Trailer Connected
When there is no trailer connected, Trailer
Profiles cannot be activated but most
options can be edited.
Trailer Brake Gain Memory
The system can store the brake gain setting
of a Trailer Profile or a Guest Trailer Profile.
When a Trailer Profile or Guest Trailer Profile
is selected, and a brake gain setting is set
for that Trailer Profile, the system will recall
the stored brake gain value.
If a Trailer Profile is already active and the
brake gain setting has been set for that
Trailer Profile, the system will recall the
brake gain value whenever the vehicle is
turned on.If there was an error in setting the brake
gain for a Trailer Profile, there will be a
notification. This pop-up will not appear if
the Guest Trailer Profile is active or if there
is no trailer connected.
Trailer brake gain should be set for a specific
trailering condition and must be adjusted
anytime vehicle loading, trailer loading,
or road surface conditions change.
Editing a Trailer Profile
Touch the trailer profile icon/name in the
Status View to access the Trailer
Profile view:
.Trailer Name
.Total Mileage
.Average Fuel Economy
.Set as Default Trailer
.GCW Alert
.Tow/Haul Mode Reminder Alert
.Theft Alert
.Maintenance Alert
.Delete/Remove Trailer
Trailer Name
Touch to edit the Trailer Profile’s name. Use
at least one character and no spaces.
Total Mileage
Touch to edit the Trailer Profile’s mileage.
Touch Reset to reset trailer mileage to zero,
or enter a new value and touch Save.
Effect on Maintenance Reminders
If the mileage is reset or changed, and
mileage has already accumulated, any
maintenance reminders that have been set
up will be adjusted accordingly.
Average Fuel Economy
Touch to reset the average fuel economy for
the trailer profile. Touch Reset to reset fuel
economy.
Delete/Remove Trailer
Touch to remove the Trailer Profile and all
of its settings.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
Driving and Operating 307
The plow the vehicle can carry depends on
many things, such as:
.The options the vehicle came with, and
the weight of those options.
.The weight and number of passengers to
be carried.
.The weight of items added to the vehicle,
like a tool box or truck cap.
.The total weight of any additional cargo
to be carried.
To safely carry a snow plow on the vehicle:
.With a snow plow attached, the engine
coolant temperature gauge may show a
higher temperature than while driving
without one. The snow plow could block
the airflow to the radiator. This could be
more noticeable as vehicle speed
increases. At speeds above 72 km/h
(45 mph), this may cause the engine
coolant to overheat. Move or angle the
snow plow blade to allow increased
airflow to the radiator.
.To increase the airflow, move the snow
plow blade position.
.If driving more than 24 km/h (15 mph),
angle the plow blade position.
.Make sure the weight on the front and
rear axles does not exceed the axle rating
for each.
.Follow the snowplow manufacturer’s
recommendations for any rear ballast that
may be required. Rear ballast may be
required to ensure a proper front and rear
weight distribution ratio even though the
actual weight at the front axle may be
less than the front axle rating.
.The snowplow manufacturer or installer
can assist in determining the amount of
rear ballast required to ensure that the
vehicle with the attached snowplow does
not exceed the GVW rating, the front and
rear axle ratings, or the front and rear
weight distribution ratio (refer to the GM
Upfitter Manual).
Front axle reserve capacity is the difference
between the Front Gross Axle Weight
Rating (GAWR) and the front axle weight of
the vehicle with full fuel, passengers, and
any other cargo. This is the amount of
weight that can be added to the front axle
before reaching the Front GAWR. To calculate the amount of weight any front
accessory, such as a snow plow, is adding to
the front axle, use this formula:
(W x (A + W.B.)) /W.B.= Weight the accessory
is adding to the front axle.
Where:
IW = Weight of added accessory
IA = Distance that the accessory is in
front of the front axle
IW.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

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Vehicle Care 323
normal idle speed for at least five minutes
while the vehicle is parked. If the warning is
still there, turn off the engine and get
everyone out of the vehicle until it
cools down.
If there is no sign of steam, idle the engine
for five minutes while parked. If the warning
is still displayed, turn off the engine until it
cools down.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and
the ENGINE POWER IS REDUCED message
displays, an overheat protection mode which
alternates firing groups of cylinders helps to
prevent engine damage. In this mode, a loss
in power and engine performance will be
noticed. This operating mode allows the
vehicle to be driven to a safe place in an
emergency. Driving extended distances
and/or towing a trailer in the overheat
protection mode should be avoided.
If the engine or transmission detects an
impending hot fluid condition, then the
transmission may force upshifts to limit
temperatures. Downshifts may also be
prevented in this instance. Normal operationmay continue unless the display indicates
there is a hot condition and engine should
be idled.
Caution
After driving in the overheated engine
protection operating mode, the engine oil
will be severely degraded. Any repairs
performed before the engine is cool may
cause engine damage. Allow the engine
to cool before attempting any repair.
Repair the cause of coolant loss, change
the oil, and reset the oil life system. See
Engine Oil
0314.
Engine Fan
If the vehicle has the Duramax diesel
engine, see the Duramax diesel supplement.
The vehicle has a clutched engine cooling
fan. When the clutch is engaged, the fan
spins faster to provide more air to cool the
engine. In most everyday driving conditions,
the fan is spinning slower and the clutch is
not fully engaged. This improves fuel
economy and reduces fan noise. Under
heavy vehicle loading, trailer towing, and/or
high outside temperatures, the fan speed
increases as the clutch more fully engages, so an increase in fan noise may be heard.
This is normal and should not be mistaken
as the transmission slipping or making extra
shifts. It is merely the cooling system
functioning properly. The fan will slow down
when additional cooling is not required and
the clutch partially disengages.
This fan noise may be heard when starting
the engine. It will go away as the fan clutch
partially disengages.
Power Steering Fluid
The power steering fluid reservoir is in the
engine compartment on the driver side of
the vehicle. See
Engine Compartment
Overview 0313 for reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power
steering fluid unless there is a leak
suspected in the system or an unusual noise

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Vehicle Care 339
FusesUsage
6 –
7 ELM 4 –Electronic
Lighting Module 4
8 –
9 –
10 ELM 6 –Electronic
Lighting Module 6
11 BCM 3 –Body Control
Module 3
12 Rear Window Defogger
13 Washer Front
14 –
15 –
16 –
17 IECL 1
19 DC/AC Inverter
20 IECR 2 (LD)/EBCM2 (HD) 21 –
22 IECL 2
24 Fuel Heater (DSL) Fuses
Usage
25 EBCM 1 –Electronic
Brake Control Module 1
26 –
27 Horn
28 Parking Lamp Mirror/ Grill (LD)/Parking Lamp
Left (HD)
29 Parking Lamp Right (HD)
30 ELM 3 –Electronic
Lighting Module 3
31 ELM 1 –Electronic
Lighting Module 1
32 –
33 Not R/C
34 Radars (LD) 37 MISC IP Headliner Ignition
38 Seat Fan Ignition
39 Trailer Ignition Module
40 Misc Ignition 41 Trailer Parking Lamp Fuses
Usage
42 Tail Lamp Left (HD)
44 DEFC/ICCM Ignition (LD/ HD)/FTZM Ignition (HD)
45 Secondary Axle Motor
46 Engine Control Module Ignition
47 –
48 –
49 Transmission Auxiliary Oil Pump (LD)
50 A/C Clutch 51 Transfer Case Control Module
52 Front Wiper
53 Center High-Mounted Stop Lamp
54 Tail Lamp Right (HD) 55 Trailer Back-up Lamp
56 SADS (LD)/Fuel Tank Zone Module 2 (HD)
57 TTPM/SBZA
58 Starter Motor (LD)

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
340 Vehicle Care
FusesUsage
60 Powertrain Sensor 2 (DSL)
61 Active Hydraulic Steering (HD)
62 DEFC Batt 1/CVS
63 Trailer Brake
65 –
66 Cooling Fan Motor Left (LD)
67 –
68 DEFC Batt 2
69 Starter Pinion (LD Gas)/ Starter Motor (HD)
71 Cooling Fan Lower (LD)
72 Cooling Fan Right (LD)
73 Trailer Stop/Turn Lamp Left
74 Trailer Interface Module 2
75 Integrated Chassis Control Module
76 Electric RNG BDS Fuses
Usage
78 Engine Control Module
79 Cabin Cool Pump 17W (LD)/Auxiliary
Battery (HD)
80 Powertrain Sensor 1 (DSL)
81 Trailer Stop/Turn Lamp Right
82 Trailer Interface Module 1
83 FTZM 1
84 Trailer Battery 85 –
86 Engine Control Module 87 Injector B Even
88 O2 B Sensor
89 O2 A Sensor
90 Injector A Odd 91 Engine Control Module Throttle Control (HD) Fuses
Usage
92 Cool Fan Clutch (HD DSL)/Aeroshutter
(LD/HD)
Relays Usage
5 Rear Window Defogger
18 DC/AC Inverter
23 Fuel Heater (DSL)
35 Parking Lamp
36 Run/Crank
43 Secondary Axle Motor
59 A/C Clutch
64 Starter Motor (LD)/Cool Fan Clutch (HD DSL)
70 Starter Pinion (LD Gas)/ Starter Motor (HD)
77 Powertrain

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
350 Vehicle Care
Tire Pressure
Tires need the correct amount of air
pressure to operate effectively.
{Warning
Neither tire underinflation nor
overinflation is good. Underinflated
tires, or tires that do not have
enough air, can result in:
.Tire overloading and overheating,
which could lead to a blowout
.Premature or irregular wear
.Poor handling
.Reduced fuel economy for
internal combustion engine
vehicles
.Reduced range for electric vehicles
Overinflated tires, or tires that have
too much air, can result in:
.Unusual wear
.Poor handling
.Rough ride
(Continued)
Warning (Continued)
.Needless damage from road
hazards
The Tire and Loading Information label
on the vehicle indicates the original
equipment tires and the correct cold
tire inflation pressures. The
recommended pressure is the minimum
air pressure needed to support the
vehicle's maximum load carrying
capacity.
For additional information regarding
how much weight the vehicle can carry,
and an example of the Tire and Loading
Information label, see Vehicle Load
Limits 0210. How the vehicle is loaded
affects vehicle handling and ride
comfort. Never load the vehicle with
more weight than it was designed to
carry.
When to Check
Check the pressure of the tires once a
month or more. Do not forget the spare, if the vehicle
has one. See
Full-Size Spare Tire 0375
for additional information.
How to Check
Use a good quality pocket-type gauge
to check tire pressure. Proper tire
inflation cannot be determined by
looking at the tire. Check the tire
inflation pressure when the tires are
cold, meaning the vehicle has not been
driven for at least three hours or no
more than 1.6 km (1 mi).
Remove the valve cap from the tire
valve stem. Press the tire gauge firmly
onto the valve to get a pressure
measurement. If the cold tire inflation
pressure matches the recommended
pressure on the Tire and Loading
Information label, no further adjustment
is necessary. If the inflation pressure is
low, add air until the recommended
pressure is reached. If the inflation
pressure is high, press on the metal
stem in the center of the tire valve to
release air.