2023 GMC SIERRA check engine

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
212 Driving and Operating
Hydroplaning
Hydroplaning is dangerous. Water can build
up under the vehicle's tires so they actually
ride on the water. This can happen if the
road is wet enough and you are going fast
enough. When the vehicle is hydroplaning, it
has little or no contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to slow
down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet weather
driving tips include:
.Allow extra following distance.
.Pass with caution.
.Keep windshield wiping equipment in
good shape.
.Keep the windshield washer fluid reservoir
filled.
.Have good tires with proper tread depth.
SeeTires 0337.
.Turn off cruise control.
Hill and Mountain Roads
Driving on steep hills or through mountains
is different than driving on flat or rolling
terrain. Tips include:
.Keep the vehicle serviced and in good
shape.
.Check all fluid levels and brakes, tires, and
cooling system.
.Shift to a lower gear when going down
steep or long hills.
{Warning
Using the brakes to slow the vehicle on a
long downhill slope can cause brake
overheating, can reduce brake
performance, and could result in a loss of
braking. Shift the transmission to a lower
gear to let the engine assist the brakes
on a steep downhill slope.
{Warning
Coasting downhill in N (Neutral) or with
the ignition off is dangerous. This can
cause overheating of the brakes and loss
of steering assist. Always have the engine
running and the vehicle in gear.
.Drive at speeds that keep the vehicle in
its own lane. Do not swing wide or cross
the center line.
.Be alert on top of hills; something could
be in your lane (e.g., stalled car, crash).
.Pay attention to special road signs (e.g.,
falling rocks area, winding roads, long
grades, passing or no-passing zones) and
take appropriate action.
Winter Driving
Driving on Snow or Ice
Caution
To avoid damage to the wheels and
brake components, always clear snow and
ice from inside the wheels and
underneath the vehicle before driving.
Snow or ice between the tires and the road
creates less traction or grip, so drive
carefully. Wet ice can occur at about 0 °C
(32 °F) when freezing rain begins to fall.
Avoid driving on wet ice or in freezing rain
until roads can be treated.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
226 Driving and Operating
the engine and transmission gently until
the oil warms up and lubricates all
moving parts.
Engine Heater
If equipped, the engine heater can provide
easier starting and better fuel economy
during engine warm-up in cold weather
conditions at or below−18 °C (0 °F). Vehicles
with an engine heater should be plugged in
at least four hours before starting. An
internal thermostat in the plug-end of the
cord may exist, which will prevent engine
heater operation at temperatures above
−18 °C (0 °F).
{Warning
Do not plug in the engine block heater
while the vehicle is parked in a garage or
under a carport. Property damage or
personal injury may result. Always park
the vehicle in a clear open area away
from buildings or structures.
To Use the Engine Heater
1. Turn off the engine.
2. Check the heater cord for damage. If it is damaged, do not use it. See your dealer
for a replacement. Inspect the cord for
damage yearly.
3. Plug the heater cord into the connector in the front fascia.
4. Plug the cord into a grounded 110-volt AC outlet that is protected by a ground
fault detection function.
{Warning
Improper use of the heater cord or an
extension cord can damage the cord and
may result in overheating and fire.
.Plug the cord into a three-prong
electrical utility receptacle that is
protected by a ground fault detection
function. An ungrounded outlet could
cause an electric shock.
.Use a weatherproof, heavy-duty,
15 amp-rated extension cord if needed.
Failure to use the recommended
extension cord in good operating
condition, or using a damaged heater
or extension cord, could make it
overheat and cause a fire, property
damage, electric shock, and injury.
.Do not operate the vehicle with the
heater cord permanently attached to
the vehicle. Possible heater cord and
thermostat damage could occur.
.While in use, do not let the heater
cord touch vehicle parts or sharp
edges. Never close the hood on the
heater cord.
(Continued)

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 241
HSA is available when the vehicle is facing
uphill in a forward gear, or when facing
downhill in R (Reverse). The vehicle must
come to a complete stop on a grade for HSA
to activate.
Ride Control Systems
Traction Control/Electronic
Stability Control
System Operation
The vehicle has a Traction Control System
(TCS) and StabiliTrak/Electronic Stability
Control (ESC) system. These systems help
limit wheel spin and assist the driver in
maintaining control, especially on slippery
road conditions.
TCS activates if it senses any of the drive
wheels are spinning or beginning to lose
traction. When this happens, TCS applies the
brakes to the spinning wheels and reduces
engine power to limit wheel spin.
StabiliTrak/ESC activates when the vehicle
senses a difference between the intended
path and the direction the vehicle is actually
traveling. StabiliTrak/ESC selectively applies
braking pressure to any one of the vehicle
wheel brakes to assist the driver in keepingthe vehicle on the intended path. Trailer
Sway Control (TSC) is also on automatically
when the vehicle is started. See
Trailer Sway
Control (TSC) 0285.
If cruise control is being used and traction
control or StabiliTrak/ESC begins to limit
wheel spin, cruise control will disengage.
Cruise control may be turned back on when
road conditions allow.
Both systems come on automatically when
the vehicle is started and begins to move.
The systems may be heard or felt while
they are operating or while performing
diagnostic checks. This is normal and does
not mean there is a problem with the
vehicle.
It is recommended to leave both systems on
for normal driving conditions, but it may be
necessary to turn TCS off if the vehicle gets
stuck in sand, mud, ice, or snow. See If the
Vehicle Is Stuck 0214 and “Turning the
Systems Off and On” later in this section.
When the transfer case (if equipped) is in
Four-Wheel Drive Low, the stability system
is automatically disabled,
gcomes on, and
the appropriate message will appear on the Driver Information Center (DIC). Both
traction control and StabiliTrak/ESC are
automatically disabled in this condition.
The indicator light for both systems is in the
instrument cluster. This light will:
.Flash when TCS is limiting wheel spin.
.Flash when StabiliTrak/ESC is activated.
.Turn on and stay on when either system
is not working.
If either system fails to turn on or to
activate, a message displays in the Driver
Information Center (DIC), and
dcomes on
and stays on to indicate that the system is
inactive and is not assisting the driver in
maintaining control. The vehicle is safe to
drive, but driving should be adjusted
accordingly.
If
dcomes on and stays on:
1. Stop the vehicle.
2. Turn the engine off and wait 15 seconds.
3. Start the engine.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 267
{Warning
Fuel vapors and fuel fires burn violently
and can cause injury or death.
Follow these guidelines to help avoid
injuries to you and others:
.Read and follow all the instructions on
the fuel pump island.
.Turn off the engine when refueling.
.Keep sparks, flames, and smoking
materials away from fuel.
.Do not leave the fuel pump
unattended.
.Avoid using electronic devices while
refueling.
.Do not re-enter the vehicle while
pumping fuel.
.Keep children away from the fuel
pump and never let children
pump fuel.
.Before touching the fill nozzle, touch a
metallic object to discharge static
electricity from your body.(Continued)
Warning (Continued)
.Fuel can spray out if the fuel cap is
opened too quickly. This spray can
happen if the tank is nearly full, and is
more likely in hot weather. Open the
fuel cap slowly and wait for any hiss
noise to stop, then unscrew the cap all
the way.
Turn the fuel cap counterclockwise to
remove. Fully insert and latch the fill nozzle,
begin fueling. For models with dual fuel
tanks, the fuel gauge shows an average of
both tanks. When refueling, refuel the
primary front tank first, then add fuel to the
auxiliary rear tank.
{Warning
Overfilling the fuel tank by more than
three clicks of a standard fill nozzle may
cause:
.Vehicle performance issues, including
engine stalling and damage to the fuel
system.
.Fuel spills.
.Under certain conditions, fuel fires. Be careful not to spill fuel. Wait five seconds
after you have finished pumping before
removing the fill nozzle. Clean fuel from
painted surfaces as soon as possible. See
Exterior Care
0374. Reinstall the cap by
turning it clockwise until it clicks.
{Warning
If a fire starts while you are refueling, do
not remove the fill nozzle. Shut off the
flow of fuel by shutting off the pump or
by notifying the station attendant. Leave
the area immediately.
Caution
If a new fuel cap is needed, get the right
type of cap from your dealer. The wrong
type of fuel cap may not fit properly,
may turn on the malfunction indicator
lamp, and could damage the fuel system
and emissions system. See Malfunction
Indicator Lamp (Check Engine Light)
0 120.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
270 Driving and Operating
moving and then manually apply the trailer
brake controller to check that the trailer
brakes work. During the trip, occasionally
check that the cargo and trailer are secure
and that the lamps and any trailer brakes
are working.
Towing with a Stability Control System
When towing, the stability control system
might be heard. The system reacts to
vehicle movement caused by the trailer,
which mainly occurs during cornering. This is
normal when towing heavier trailers.
Following Distance
Stay at least twice as far behind the vehicle
ahead as you would when driving without a
trailer. This can help to avoid heavy braking
and sudden turns.
Passing
More passing distance is needed when
towing a trailer. The combination of the
vehicle and trailer will not accelerate as
quickly and is much longer than the vehicle
alone. It is necessary to go much farther
beyond the passed vehicle before returning
to the lane. Pass on level roadways. Avoid
passing on hills if possible.
Backing Up
Hold the bottom of the steering wheel with
one hand. To move the trailer to the left,
move that hand to the left. To move the
trailer to the right, move that hand to the
right. Always back up slowly and, if possible,
have someone guide you.
Making TurnsCaution
Turn more slowly and make wider arcs
when towing a trailer to prevent damage
to your vehicle. Making very sharp turns
could cause the trailer to contact the
vehicle.
Make wider turns than normal when towing,
so the trailer will not go over soft shoulders,
over curbs, or strike road signs, trees,
or other objects. Always signal turns well in
advance. Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is not
shifted down, the brakes may overheat and
result in reduced braking efficiency. 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
Overheating 0313.
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 0246.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer on a
level surface when possible.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
272 Driving and Operating
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 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
Schedule 0385. 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 0313.
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, and
durability. 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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 285
.There is an electrical fault in the wiring to
the trailer brakes. This message will
continue as long as there is an electrical
fault in the trailer wiring. This message
will also turn off if it is acknowledged.
To determine whether the electrical fault is
on the vehicle side or trailer side of the
trailer wiring harness connection: 1. Disconnect the trailer wiring harness from the vehicle.
2. Turn the vehicle off.
3. Wait 10 seconds, then turn the vehicle back to RUN.
4. If the CHECK TRAILER WIRING message reappears, the electrical fault is on the
vehicle side.
If the CHECK TRAILER WIRING message only
reappears when connecting the trailer wiring
harness to the vehicle, the electrical fault is
on the trailer side.
TRAILER BRAKES DISABLED SERVICE
REQUIRED: This message will display when
there is a problem with the ITBC system.
If this message continues over multiple
restarts, have the vehicle serviced. If either the CHECK TRAILER WIRING, TRAILER
BRAKES DISABLED SERVICE REQUIRED,
SERVICE TRAILER BRAKES, HOLD LAST KNOWN
GAIN, or REDUCED TRAILER BRAKING
message displays while driving, the ITBC
system may not be fully functional or may
not function at all. When traffic conditions
allow, carefully pull the vehicle over to the
side of the road and turn the vehicle off.
Check the wiring connection to the trailer
and turn the vehicle back on. If either of
these messages continue, either the vehicle
or trailer needs service.
A GM dealer may be able to diagnose and
repair problems with the trailer. However,
any diagnosis and repair of the trailer is not
covered under the vehicle warranty. Contact
your trailer dealer for assistance with trailer
repairs and trailer warranty information.
Trailer Sway Control (TSC)
Vehicles with StabiliTrak/Electronic Stability
Control (ESC) have a Trailer Sway Control
(TSC) feature. Trailer sway is unintended
side-to-side motion of a trailer while towing.
If the vehicle is towing a trailer and the TSC
detects that sway is increasing, the vehicle
brakes are selectively applied at each wheel,
to help reduce excessive trailer sway.If equipped with the Integrated Trailer Brake
Control (ITBC) system, and the trailer has an
electric brake system, StabiliTrak/ESC may
also apply the trailer brakes.
If TSC is enabled, the Traction Control
System (TCS)/StabiliTrak/ESC warning light
will flash on the instrument cluster. Reduce
vehicle speed by gradually removing your
foot from the accelerator. If trailer sway
continues, StabiliTrak/ESC can reduce engine
torque to help slow the vehicle. TSC will not
function if StabiliTrak/ESC is turned off. See
Traction Control/Electronic Stability Control
0
241.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 297
Theft Alert
A theft alert can be set if a trailer is
connected and the alert is enabled. When
the trailer is disconnected and the vehicle is
off, an alarm will sound.
Touch Theft Alert in Settings to view the
Theft Alert settings page. These alerts are
based on the Trailer Profile, so the settings
for each Trailer Profile must be turned on or
off. Touch a profile to view more
information or adjust the setting for that
profile.
This setting will be off by default for each
Trailer Profile, including the Guest Trailer
Profile.
A smartphone will receive a notification that
the trailer related to the selected Trailer
Profile is disconnected from the vehicle,
if the setting is on for the active Trailer
Profile, the vehicle has an OnStar or
connected service plan and the smartphone
number has been added to the account for
this notification.
If the setting is turned off for a given Trailer
Profile, the smartphone will not receive this
security notification even if the Trailer
Profile is active.
Tow/Haul Mode Reminder
This is a reminder to turn on the Tow/Haul
Mode when towing a trailer. SeeTow/Haul
Mode 0234.
Touch Tow/Haul Mode Reminder in Settings
to view the Tow/Haul Mode Reminder
settings page. These alerts are based on the
Trailer Profile, so the settings for each
Trailer Profile must be turned on or off.
Touch a profile to view more information or
to adjust the setting for that profile.
This setting will default to OFF for each
Trailer Profile, including the Guest Trailer
Profile.
If Tow/Haul Mode is off and this setting is
on for a Trailer Profile, each time the vehicle
is turned on a reminder will appear to turn
on Tow/Haul Mode when the Trailer Profile
is active.
If Tow/Haul Mode is on and this setting is
on for a Trailer Profile, the reminder will not
appear when the Trailer Profile is active.
Trailer Length Indicator
Touch Trailer Length Indicator to view the
Trailer Length Indicator settings page. If this
setting is ON a guideline is displayed in the side mirror camera view to indicate the rear
of the attached trailer. If this setting is OFF
the guideline will not be displayed.
This setting will default to OFF if the trailer
length indicator feature is not set up. See
"Towing Assistance" for details on the setup.
Conversions and Add-Ons
Add-On Electrical Equipment
{Warning
The Data Link Connector (DLC) is used for
vehicle service and Emission Inspection/
Maintenance testing. See
Malfunction
Indicator Lamp (Check Engine Light) 0120
. A device connected to the DLC —such
as an aftermarket fleet or driver-behavior
tracking device —may interfere with
vehicle systems. This could affect vehicle
operation and cause a crash. Such devices
may also access information stored in the
vehicle’s systems.