
GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
224 Driving and Operating
Service Mode
This power mode is available for service and
diagnostics, and to verify the proper
operation of the malfunction indicator lamp
as may be required for emission inspection
purposes. With the vehicle off, and the
brake pedal not applied, pressing and
holding the ENGINE START/STOP button for
more than five seconds will place the vehicle
in Service Mode. The instruments and audio
systems will operate as they do when the
vehicle is on, but the vehicle will not be able
to be driven. The engine will not start in
Service Mode. Press the ENGINE START/STOP
button again to turn the vehicle off.
Starting the Engine
If the vehicle has a diesel engine, see the
Duramax diesel supplement.
Caution
If you add electrical parts or accessories,
you could change the way the engine
operates. Any resulting damage would
not be covered by the vehicle warranty.
SeeAdd-On Electrical Equipment 0338. Move the shift lever to P (Park) or
N (Neutral). To restart the engine when the
vehicle is already moving, use
N (Neutral) only.
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you could
damage the transmission. Shift to P (Park)
only when the vehicle is stopped.
Starting Procedure
1. The remote key must be in the vehicle.
Press ENGINE START/STOP with the brake
pedal applied. When the engine begins
cranking, let go of the button.
The driver may observe a minor, and
temporary, brake pedal kickback when
starting the vehicle. This is normal.
The idle speed will go down as the
engine gets warm. Do not race the
engine immediately after starting it.
Operate the engine and transmission
gently to allow the oil to warm up and
lubricate all moving parts. When the low fuel warning light is on
and the FUEL LEVEL LOW message is
displayed in the Driver Information
Center (DIC), press ENGINE START/STOP
to continue engine cranking.
Caution
Cranking the engine for long periods of
time, by returning the ignition to the
START position immediately after
cranking has ended, can overheat and
damage the cranking motor, and drain
the battery. Wait at least 15 seconds
between each try, to let the cranking
motor cool down.
2. If the engine does not start after five to 10 seconds, especially in very cold
weather (below −18 °C or 0 °F), it could
be flooded with too much gasoline. Try
pushing the accelerator pedal all the way
to the floor and holding it there while
pressing ENGINE START/STOP for up to a
maximum of 15 seconds. Wait at least
15 seconds between each try, to allow
the cranking motor to cool down. When
the engine starts, let go of the button
and accelerator. If the vehicle starts
briefly but then stops again, do the
same thing. This clears the extra gasoline

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Driving and Operating 229
Warning (Continued)
P (Park). SeeShifting Into Park
(Mechanical Shifter) 0227 or
Shifting Into Park (Electronic Shifter)
0 228. If you are towing a trailer, see
Driving Characteristics and Towing Tips
0 309.
Shifting out of Park (Mechanical
Shifter)
This vehicle is equipped with an electronic
shift lock release system. The system is
designed to prevent movement of the shift
lever out of P (Park), unless the brake pedal
is applied and the ignition is on or in
Service Mode.
The shift lock release is always functional
except in the case of an uncharged or low
voltage –less than 9 volt –battery.
If the vehicle has an uncharged or low
voltage battery, try charging or jump
starting the battery. See Jump Starting -
North America 0407.
To shift out of P (Park): 1. Apply the brake pedal. 2. Release the parking brake if it is applied.
See Electric Parking Brake 0245.
3. Pull the shift lever toward you, then move it to the desired position, and
release.
If the vehicle still cannot be shifted out of
P (Park): 1. Ease the pressure on, or release the shift lever.
2. While holding the brake pedal, push the shift lever all the way into P (Park).
3. Pull the shift lever toward you, then move it to the desired position, and
release.
If there is still a problem shifting, have the
vehicle serviced soon.
Shifting out of Park (Electronic
Shifter)
This vehicle is equipped with an electronic
transmission. The shift lock release button is
designed to prevent inadvertent shifting out
of P (Park).
To shift out of P (Park): 1. Ensure the engine is running.
2. Apply the brake pedal. 3. Press and hold the shift lock release
button on the shift lever.
4. Move the shift lever to the desired position. For N (Neutral) hold the lever in
the N (Neutral) position until the N
indicator illuminates red.
5. The P indicator will turn white and the gear indicator on the shift lever will turn
red when the vehicle is no longer in
P (Park).
6. After releasing the shift lever, it will return to the center position.
If the vehicle cannot shift from P (Park), a
Driver Information Center (DIC) message
may be displayed. Ensure the engine is
running, the brake pedal is applied, and the
shift lock release button is pressed when
you are attempting to shift out of P (Park).
If all of these conditions are met but the
vehicle will not shift out of P (Park), see
your dealer for service.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
234 Driving and Operating
The shift lever always starts from a center
position, represented by an up/down arrow
on the shift pattern. After releasing the shift
lever, it will return to the center position.
The transmission does not operate when the
vehicle is off.
If the vehicle is in accessory mode, the
transmission can be shifted into P (Park).
If the vehicle is turned off while at a
relatively high vehicle speed, the
transmission will automatically shift to
N (Neutral). Once the vehicle is stopped,
P (Park) is automatically selected.
P :This position locks the rear wheels. Use
P (Park) when starting the engine to prevent
the vehicle from moving easily.
{Warning
It is dangerous to get out of the vehicle
if the shift lever is not fully in P (Park)
with the parking brake firmly set. The
vehicle can roll.
Do not leave the vehicle when the engine
is running. If you have left the engine
running, the vehicle can move suddenly.
You or others could be injured. To be
sure the vehicle will not move, even
when you are on fairly level ground,
always set the parking brake and move
the shift lever to P (Park). See Shifting
Into Park (Mechanical Shifter) 0227 or
Shifting Into Park (Electronic Shifter)
0 228 and Driving Characteristics and
Towing Tips 0309.
{Warning
If equipped with four-wheel drive, the
vehicle will be free to roll if the transfer
case is in N (Neutral), even when the shift
lever is in P (Park). You or someone else
could be seriously injured. Be sure the
transfer case is in a drive gear —2
m, 4m,
(Continued)
Warning (Continued)
or 4n— or set the parking brake before
placing the transfer case in N (Neutral).
See Four-Wheel Drive 0240.
This vehicle is equipped with an
electronically controlled transmission. The
shift lock release button is designed to
prevent inadvertent shifting out of P (Park)
unless the ignition is on, the brake pedal is
applied, and the shift lock release button is
pressed.
When the vehicle is stopped, press ENGINE
START/STOP to turn off the vehicle. The
transmission will shift to P (Park)

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Driving and Operating 235
automatically unless the vehicle is in
N (Neutral), See“Car Wash Mode” later in
this section.
The vehicle will not shift into P (Park) if it is
moving too fast. Stop the vehicle and shift
into P (Park).
To shift in and out of P (Park), see Shifting
Into Park (Mechanical Shifter) 0227 or
Shifting Into Park (Electronic Shifter) 0228
and Shifting out of Park (Mechanical Shifter)
0 229 or]Shifting out of Park (Electronic
Shifter) 0229.
Service Shift Lever Message
If the message SERVICE SHIFTER SEE
OWNER’S MANUAL appears in the Driver
Information Center (DIC), the shift lever
needs service. Have the vehicle serviced as
soon as possible. If the vehicle is
automatically shifting into P (Park), check to
see if the P (Park) button on top of the shift
lever is stuck. To operate the vehicle, hold
the shift lever in the desired gear,
R (Reverse) or D (Drive), until vehicle speed
exceeds 15 km/h (10 mph), then release the
shift lever.
R : Use this gear to back up. If the vehicle is shifted from either
R (Reverse) to D (Drive) or L (Low), or L (Low)
or D (Drive) to R (Reverse) while the speed is
too high, the vehicle may shift to
N (Neutral). Reduce the vehicle speed and
try the shift again.
To shift into R (Reverse):
1. Bring the vehicle to a complete stop.
2. Press and hold the shift lock release button on the side of the shift lever.
3. From the center position, move the shift lever forward to R (Reverse). R will be
illuminated in red.
4. After releasing the shift lever, it will return to the center position.
To shift out of R (Reverse): 1. Bring the vehicle to a complete stop.
2. Shift to the desired gear.
3. After releasing the shift lever, it will return to the center position.
At low vehicle speeds, R (Reverse) can be
used to rock the vehicle back and forth to
get out of snow, ice, or sand without
damaging the transmission. See If the
Vehicle Is Stuck 0214. N :
In this position, the engine does not
connect with the wheels. To restart the
engine when the vehicle is already moving,
use N (Neutral) only.
{Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is firmly on
the brake pedal, the vehicle could move
very rapidly. You could lose control and
hit people or objects. Do not shift into a
drive gear while the engine is running at
high speed.
Caution
Shifting out of P (Park) or N (Neutral) with
the engine running at high speed may
damage the transmission. The repairs
would not be covered by the vehicle
warranty. Be sure the engine is not
running at high speed when shifting the
vehicle.
The vehicle is not designed to stay in
N (Neutral) for more than five minutes.
It may automatically shift into P (Park).

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
236 Driving and Operating
N (Neutral) is not intended for towing. If the
vehicle needs to be towed, seeTowing the
Vehicle 0409.
To shift into N (Neutral): 1. Move the shift lever forward to N (Neutral).
.If the vehicle is in P (Park), apply the
brake pedal and press the shift lock
release button while moving the shift
lever forward.
.The N indicator will illuminate in red.
2. After releasing the shift lever, it will return to the center position.
To shift out of N (Neutral): 1. Bring the vehicle to a complete stop.
2. Shift to the desired gear. If shifting from N (Neutral) to R (Reverse), press the shift
lock release button.
3. After releasing the shift lever, it will return to the center position.
Car Wash Mode
This vehicle includes a Car Wash Mode that
allows the vehicle to remain in N (Neutral)
for use in automatic car washes. Car Wash Mode (Engine Off
–Driver in
Vehicle)
To place the vehicle in N (Neutral) with the
engine off and the vehicle occupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Shift to N (Neutral).
4. Turn off the engine and release the brake pedal.
5. The indicator should continue to show N. If it does not, repeat Steps 2–4.
6. The vehicle is now ready for the car wash.
Car Wash Mode (Engine Off –Driver Out of
Vehicle)
To place the vehicle in N (Neutral) with the
engine off and the vehicle unoccupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Open the door.
4. Shift to N (Neutral).
5. Turn off the engine and release the brake pedal.
6. The indicator should continue to show N. If it does not, repeat Steps 2–5. 7. Exit the vehicle and close the door. The
vehicle is now ready for the car wash.
8. The vehicle may automatically shift to P (Park) upon re-entry.
Car Wash Mode (Engine On –Driver in
Vehicle)
To place the vehicle in N (Neutral) with the
engine on and the vehicle occupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Shift to N (Neutral).
4. Release the brake pedal. The vehicle is now ready for the car wash.
Car Wash Mode (Engine On –Driver Out of
Vehicle)
To place the vehicle in N (Neutral) with the
engine on and the vehicle unoccupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Open the door.
4. Shift to N (Neutral), then release the brake pedal.
5. The indicator should continue to show N. If it does not, repeat Steps 2–4.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
Driving and Operating 237
6. Exit the vehicle and close the door. Thevehicle is now ready for the car wash.
7. The vehicle may automatically shift to P (Park) upon re-entry.
Caution
A transmission hot message may display
if the automatic transmission fluid is too
hot. Driving under this condition can
damage the vehicle. Stop and idle the
engine to cool the automatic
transmission fluid. This message clears
when the transmission fluid has cooled
sufficiently.
D : This position is for normal driving.
If more power is needed for passing, press
the accelerator pedal down.
To shift into D (Drive):
1. Bring the vehicle to a complete stop.
2. From the center position, move the shift lever back.
.If the vehicle is in P (Park) press the
shift lock release button while pulling
the shift lever back.
.D will illuminate in red.
.After releasing the shift lever, it will
return to the center position.
To shift out of D (Drive): 1. Bring the vehicle to a complete stop.
2. Shift to the desired gear.
3. After releasing the shift lever, it will return to the center position.
Downshifting the transmission on a slippery
road could result in skidding. See “Skidding”
under Loss of Control 0208.
Caution
Spinning the tires or holding the vehicle
in one place on a hill using only the
accelerator pedal may damage the
transmission. The repair will not be
covered by the vehicle warranty. If the
vehicle is stuck, do not spin the tires.
When stopping on a hill, use the brakes
to hold the vehicle in place.
Manual Mode (Mechanical
Shifter)
Range Selection Mode
Range Selection Mode helps control the
vehicle transmission and vehicle speed while
driving downhill or towing a trailer.
It permits the manual selection of a desired
gear range.
To use this feature:
1. Move the shift lever to L (Manual Mode).
2. Press the plus/minus buttons on the shift lever to select the desired gear
range for current driving conditions.
When the shift lever is moved from
D (Drive) to L (Manual Mode), a number
displays next to the L, indicating the current
transmission range.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
238 Driving and Operating
This number is the highest gear that the
transmission will allow while operating in
L (Manual Mode). All gears below that
number are available. As driving conditions
change, the transmission can automatically
shift to lower gears. For example, when L5 is
selected, 1 (First) through 5 (Fifth) gears are
automatically shifted by the transmission,
but 6 (Sixth) cannot be used until the plus/
minus button on the shift lever is used to
change to the range.
In vehicles with gasoline engines, when the
shift lever is moved from D (Drive) to
L (Manual Mode), a downshift may occur.
The gear that the transmission is operating
in when the shift lever is moved from D
(Drive) to L (Manual Mode) determines if a
downshift occurs. See the following charts.8-Speed Automatic Transmission
Gear before shifting
from D (Drive) to
L (Manual Mode) 8th 7th 6th 5th 4th 3rd 2nd 1st
Range after shifting
from D (Drive) to
L (Manual Mode) –
Tow/Haul not engaged L6 L6 L5 L4 L3 L3 L2 L1
Range after shifting
from D (Drive) to
L (Manual Mode) –
Tow/Haul engaged L6 L5 L4 L3 L3 L3 L2 L1

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
240 Driving and Operating
When shifting to L (Low), the transmission
will shift to a preset lower gear range. For
this preset range, the highest gear available
will be displayed next to the L in the DIC.
SeeDriver Information Center (DIC) (Base
Level) 0128 orDriver Information Center
(DIC) (Uplevel) 0130. All gears below that
number are available to use. For example,
when 4 (Fourth) is shown next to the L,
1 (First) through 4 (Fourth) gears are shifted
automatically. To shift to 5 (Fifth) gear, tap
the right steering wheel control or shift into
D (Drive).
L (Low) will prevent shifting to a lower gear
range if the engine speed is too high. If the
vehicle speed is not reduced within the time
allowed, the lower gear range shift will not
be completed. Slow the vehicle, then tap the
left steering wheel control to the desired
lower gear range.
Cruise control can be used while in ERS.
Tow/Haul Mode
The Tow/Haul Mode adjusts the
transmission shift pattern to reduce shift
cycling. This provides increased performance,
vehicle control, and enhanced transmission
and engine cooling when driving down steep
hills or mountain grades, when towing, or when hauling heavy loads. See
Driver
Mode Control 0249 to activate Tow/
Haul Mode.
For vehicles without Driver Mode Control,
press the Tow/Haul button on the center
stack.
If equipped, the Stop/Start system will
become unavailable when Tow/Haul Mode is
active.
If equipped with Active Hydraulic Assist, the
vehicle will provide a stiffer steering
response when Tow/Haul mode is engaged
to provide enhanced steering functionality.
Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is only
enabled while the Tow/Haul Mode is
selected and the vehicle is not in the Range
Selection Mode. See Manual Mode
(Mechanical Shifter) 0237 or
Manual Mode (Electronic Shifter) 0239.
Tow/Haul Mode Grade Braking assists in
maintaining desired vehicle speeds when
driving on downhill grades by using the
engine and transmission to slow the vehicle.
See Towing Equipment 0317.
Drive Systems
Four-Wheel Drive
If equipped, four-wheel drive engages the
front axle for extra traction.
Read the appropriate section for transfer
case operation before using.
Caution
Do not drive on clean, dry pavement in
4
mand 4n(if equipped) for an extended
period of time. These conditions may
cause premature wear on the vehicle’s
powertrain.