check transmission fluid GMC SIERRA 2018 Owner's Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 145
Transmission
Temperature Gauge
Metric Standard Theme
English Standard Theme
This gauge appears when the
vehicle is in Tow/Haul Mode and
shows the transmission fluid
temperature. If the gauge is reading
in the red area and/or a message
appears in the Driver Information
Center (DIC), the vehicle must be
stopped and the cause checked.
One possible cause is a low fluid
level in the transmission.
Caution
Do not drive the vehicle while the
transmission fluid is overheating,
or the transmission can be
damaged. This could lead to
costly repairs that would not be
covered by the warranty.
Voltmeter Gauge
Standard Theme
When the ignition is on, this gauge
indicates the battery voltage.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
158 Instruments and Controls
Cruise Control Light
For vehicles with cruise control, the
cruise control light is white when the
cruise control is on and ready, and
turns green when the cruise control
is set and active.
The light turns off when the cruise
control is turned off. SeeCruise
Control 0285.
Door Ajar Light
This light comes on when a door is
open or not securely latched. Before
driving, check that all doors are
properly closed.
Information Displays
Driver Information Center
(DIC) (Base Level Cluster)
The DIC displays are shown in the
center of the instrument cluster. The
displays show the status of many
vehicle systems. The trip odometer
reset stem in the instrument cluster
is used to access the DIC menu
items.
DIC Menu Items
Turn the trip odometer reset stem to
scroll through the following menu
items:
.
Digital Speedometer
. Trip
. Fuel Range
. Average Fuel Economy
. Tire Pressure
. Remaining Oil Life
. Transmission Fluid Temperature
. Trailer Brake
. Hourmeter

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 245
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, cooling system, and
transmission.
. 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, accident).
. 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
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.
For Slippery Road Driving:
.Accelerate gently. Accelerating
too quickly causes the wheels to
spin and makes the surface
under the tires slick.
. Turn on Traction Control. See
Traction Control/Electronic
Stability Control 0282.
. The Antilock Brake System
(ABS) improves vehicle stability
during hard stops, but the
brakes should be applied sooner
than when on dry pavement.
See Antilock Brake System
(ABS) 0280.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 307
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule0448.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See Engine Overheating
0 363.
Trailer Towing
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
Do not tow a trailer during break-in.
See New Vehicle Break-In 0255.
{Warning
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too heavy
or the trailer brakes are
inadequate for the load, the
vehicle may not stop as expected.
The driver and passengers could
be seriously injured. The vehicle
may also be damaged; the
resulting repairs would not be
covered by the vehicle warranty.
Pull a trailer only if all the steps in
this section have been followed.
Ask your dealer for advice and
information about towing a trailer
with the vehicle.
Caution
Pulling a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To pull a trailer
correctly, follow the advice in this
section and see your dealer for
important information about
towing a trailer with the vehicle.
See Vehicle Load Limits 0248 for
more information about the vehicle's
maximum load capacity.
To identify the trailering capacity of
the vehicle, read the information in
“Weight of the Trailer” later in this
section.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 341
Vehicle Care
General Information
General Information . . . . . . . . . . 342
California Proposition65 Warning . . . . . . . . . . . . . . . . . 343
California Perchlorate Materials Requirements . . . . . 343
Accessories and Modifications . . . . . . . . . . . . . . . . 343
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 344
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 344
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 345
Engine Oil . . . . . . . . . . . . . . . . . . . . 350
Engine Oil Life System . . . . . . . 353
Automatic Transmission Fluid (6-Speed Transmission) . . . . . 354
Automatic Transmission Fluid (8-Speed Transmission) . . . . . 357
Engine Air Cleaner/Filter . . . . . . 358
Cooling System . . . . . . . . . . . . . . 359
Engine Overheating . . . . . . . . . . 363
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . 364
Engine Fan . . . . . . . . . . . . . . . . . . . 365 Power Steering Fluid (1500
Series) . . . . . . . . . . . . . . . . . . . . . . 365
Power Steering Fluid (2500/ 3500 Series) . . . . . . . . . . . . . . . . 365
Washer Fluid . . . . . . . . . . . . . . . . . 366
Brakes . . . . . . . . . . . . . . . . . . . . . . . 367
Brake Fluid . . . . . . . . . . . . . . . . . . . 368
Battery - North America . . . . . . 369
Four-Wheel Drive . . . . . . . . . . . . . 370
Front Axle . . . . . . . . . . . . . . . . . . . . 370
Rear Axle . . . . . . . . . . . . . . . . . . . . 371
Noise Control System . . . . . . . . 373
Starter Switch Check . . . . . . . . . 374
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 374
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 374
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 375
Wiper Blade Replacement . . . . 375
Windshield Replacement . . . . . 376
Gas Strut(s) . . . . . . . . . . . . . . . . . . 376
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 377
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 378
Halogen Bulbs . . . . . . . . . . . . . . . . 378 High Intensity Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . 378
LED Lighting . . . . . . . . . . . . . . . . . 378
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 378
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 380
Electrical System
High Voltage Devices andWiring . . . . . . . . . . . . . . . . . . . . . . . 380
Electrical System Overload . . . 380
Fuses and Circuit Breakers . . . 381
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 381
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 385
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . . . 386
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 389
All-Season Tires . . . . . . . . . . . . . . 389
Winter Tires . . . . . . . . . . . . . . . . . . 390
Low-Profile Tires . . . . . . . . . . . . . 390
All-Terrain Tires . . . . . . . . . . . . . . . 391
Tire Sidewall Labeling . . . . . . . . 391
Tire Designations . . . . . . . . . . . . . 393

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
346 Vehicle Care
1. Positive (+) Terminal. SeeJump Starting - North America
0426.
2. Battery - North America 0369.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System 0359.
4. Engine Air Cleaner/Filter 0358.
5. Automatic Transmission Dipstick (If Equipped). See
“How to Check Automatic
Transmission Fluid” under
Automatic Transmission Fluid
(6-Speed Transmission) 0354
or Automatic Transmission
Fluid (8-Speed Transmission)
0 357. 6. Remote Negative (–) Location.
See Jump Starting - North
America 0426.
7. Engine Cooling Fans (Out of View). See Cooling System
0 359.
8. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil 0350.
9. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil 0350. 10. Brake Fluid Reservoir. See
Brake Fluid 0368.
11. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid
0 366.
12. Engine Compartment Fuse
Block 0381.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
348 Vehicle Care
1. Positive (+) Terminal. SeeJump Starting - North America
0426.
2. Battery - North America 0369.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System 0359.
4. Engine Air Cleaner/Filter 0358.
5. Automatic Transmission Dipstick (If Equipped). See
“How to Check Automatic
Transmission Fluid” under
Automatic Transmission Fluid
(6-Speed Transmission) 0354
or Automatic Transmission
Fluid (8-Speed Transmission)
0 357. 6. Remote Negative (–) Location
(Out of View). See Jump
Starting - North America 0426.
7. Engine Cooling Fans (Out of View). See Cooling System
0 359.
8. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil 0350.
9. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil 0350. 10. Windshield Washer Fluid
Reservoir. See “Adding Washer
Fluid” under Washer Fluid
0 366.
11. Brake Fluid Reservoir. See Brake Fluid 0368.
12. Engine Compartment Fuse
Block 0381.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
350 Vehicle Care
1. Positive (+) Terminal. SeeJump Starting - North America
0426.
2. Battery - North America 0369.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System 0359.
4. Engine Air Cleaner/Filter 0358.
5. Automatic Transmission Dipstick (If Equipped). See
“How to Check Automatic
Transmission Fluid” under
Automatic Transmission Fluid
(6-Speed Transmission) 0354
or Automatic Transmission
Fluid (8-Speed Transmission)
0 357.
6. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil 0350.
7. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil 0350.
8. Engine Cooling Fan (Out of View). See Cooling System
0 359. 9. Remote Negative (–) Location.
See Jump Starting - North
America 0426.
10. Power Steering Fluid Reservoir. See Power Steering
Fluid (1500 Series) 0365 or
Power Steering Fluid (2500/
3500 Series) 0365.
11. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid
0 366.
12. Brake Fluid Reservoir. See Brake Fluid 0368.
13. Auxiliary Battery (If Equipped). SeeBattery - North America
0 369.
14. Engine Compartment Fuse
Block 0381.
If the vehicle has a diesel engine
and/or an Allison Transmission, see
the Duramax diesel supplement.
For an eAssist vehicle, see the
Silverado/Sierra supplement.Engine Oil
For diesel engine vehicles, see
“Engine Oil” in the Duramax diesel
supplement.
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
. Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
. Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
. Change the engine oil at the
appropriate time. See Engine Oil
Life System 0353.
. Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
354 Vehicle Care
How to Reset the Engine Oil
Life System
Reset the system whenever the
engine oil is changed so that the
system can calculate the next
engine oil change. Always reset the
engine oil life to 100% after every oil
change. It will not reset itself. To
reset the engine oil life system:1. Display the OIL LIFE REMAINING on the DIC. If the
vehicle does not have DIC
buttons, the vehicle must be in
P (Park) to access this display.
See Driver Information Center
(DIC) (Uplevel and Denali
Cluster) 0160 orDriver
Information Center (DIC) (Base
Level Cluster) 0158.
2. Press and hold
V, or the trip
odometer reset stem if the
vehicle does not have DIC
buttons, for several seconds.
The oil life will change
to 100%. The oil life system can also be reset
as follows:
1. Display the OIL LIFE REMAINING on the DIC.
See Driver Information Center
(DIC) (Uplevel and Denali
Cluster) 0160 orDriver
Information Center (DIC) (Base
Level Cluster) 0158.
2. Fully press the accelerator pedal slowly three times within
five seconds.
3. Display the OIL LIFE REMAINING on the DIC. If the
display shows 100%, the
system is reset.
If the vehicle has a CHANGE
ENGINE OIL SOON message and it
comes back on when the vehicle is
started and/or the OIL LIFE
REMAINING is near 0%, the engine
oil life system has not been reset.
Repeat the procedure.
Automatic Transmission
Fluid (6-Speed
Transmission)
When to Check and Change
Automatic Transmission Fluid
It is usually not necessary to check
the transmission fluid level. The only
reason for fluid loss is a
transmission leak or overheated
transmission. If a small leak is
suspected, then use the following
checking procedures to check the
fluid level. However, if there is a
large leak, then it may be necessary
to have the vehicle towed to a
dealer service department and have
it repaired before driving the vehicle
further.
Caution
Use of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
not be covered by the vehicle
warranty. Always use the (Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 355
Caution (Continued)
automatic transmission fluid listed
inRecommended Fluids and
Lubricants 0456.
Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule
0 448. Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants 0456.
How to Check Automatic
Transmission Fluid
Caution
Too much or too little fluid can
damage the transmission. Too
much can mean that some of the
fluid could come out and fall on
hot engine parts or exhaust
system parts, starting a fire. Too
little fluid could cause the (Continued)
Caution (Continued)
transmission to overheat. Be sure
to get an accurate reading if
checking the transmission fluid.
Before checking the fluid level,
prepare the vehicle: 1. Start the engine and park the vehicle on a level surface.
Keep the engine running.
2. Apply the parking brake and place the shift lever in P (Park).
3. With your foot on the brake pedal, move the shift lever
through each gear range,
pausing for about
three seconds in each range.
Then, move the shift lever back
to P (Park).
4. Allow the engine to idle (500– 800 rpm) for at least
one minute. Slowly release the
brake pedal. 5. Keep the engine running and
check the transmission fluid
temperature on the Driver
Information Center (DIC).
See Driver Information Center
(DIC) (Uplevel and Denali
Cluster) 0160 orDriver
Information Center (DIC) (Base
Level Cluster) 0158.
6. Using the transmission fluid temperature reading, determine
and perform the appropriate
check procedure. If the
transmission fluid temperature
reading is not within the
required temperature ranges,
allow the vehicle to cool,
or operate the vehicle until the
appropriate transmission fluid
temperature is reached.
Cold Check Procedure
Use this procedure only as a
reference to determine if the
transmission has enough fluid to be
operated safely until a hot check
procedure can be made. The hot
check procedure is the most
accurate method to check the fluid
level. Perform the hot check