2018 GMC SIERRA DENALI check engine light

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
8 In Brief Auxiliary Button (If Equipped).
See Add-On Electrical
Equipment 0 336 .
j Power Assist Steps 0 43 (If
Equipped).
18. Dual Automatic Climate Control
System 0 228 (If Equipped).
19. Steering Wheel Controls 0 129
(If Equipped).
Driver Information Center (DIC)
Controls. See Driver
Information Center (DIC)
(Uplevel and Denali Cluster)
0 160 or Driver Information
Center (DIC) (Base Level
Cluster) 0 158 .
20. Hood Release. See Hood
0 344 .
21. Horn 0 130 . 22. Steering Wheel Adjustment
0 129 (Out of View).
23. Cruise Control 0 285 .
Heated Steering Wheel 0 130
(If Equipped).
Forward Collision Alert (FCA)
System 0 292 (If Equipped).
24. Data Link Connector (DLC)
(Out of View). See Malfunction
Indicator Lamp (Check Engine
Light) 0 150 .
25. Parking Brake 0 281 .
26. Electronic Transfer Case Knob
(If Equipped). See Four-Wheel
Drive 0 272 .
Card Holder (If Equipped). See
Instrument Panel Storage
0 124 .Initial Drive
Information This section provides a brief
overview about some of the
important features that may or may
not be on your specific vehicle.
For more detailed information, refer
to each of the features which can be
found later in this owner ’ s manual.
Remote Keyless Entry
(RKE) System The Remote Keyless Entry (RKE)
transmitter functions may work from
up to 60 m (197 ft) away from the
vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 47When trying to start the vehicle, the
security light comes on briefly when
the ignition is turned on.
If the engine does not start and the
security light stays on, there is a
problem with the system. Turn the
ignition off and try again.
If the engine still does not start, and
the key appears to be undamaged,
try another ignition key. It may be
necessary to check the fuse. See
Fuses and Circuit Breakers 0 381 .
If the engine still does not start with
the other key, the vehicle needs
service. If the vehicle does start, the
first key may be faulty. See your
dealer. It is possible for the immobilizer
system to learn new or replacement
keys. Up to eight keys can be
programmed for the vehicle. To
program additional keys, see Keys
0 34 . To program additional
transmitters, see your dealer.
Do not leave the key or device that
disarms or deactivates the vehicle
theft system in the vehicle.
See your dealer to get a new key
blank cut exactly as the ignition key
that operates the system. Exterior Mirrors Convex Mirrors
{ WarningA convex mirror can make things,
like other vehicles, look farther
away than they really are. If you
cut too sharply into the right lane,
you could hit a vehicle on the
right. Check the inside mirror or
glance over your shoulder before
changing lanes.
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from
the driver seat.
Manual Mirrors If equipped, adjust manual mirrors
by moving the mirror up and down
or left to right to see a little of the
side of the vehicle and to have a
clear view behind the vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
128 Instruments and Controls
Instruments and
Controls Controls Steering Wheel Adjustment . . . 129
Steering Wheel Controls . . . . . . 129
Heated Steering Wheel . . . . . . . 130
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Windshield Wiper/Washer . . . . 130
Compass . . . . . . . . . . . . . . . . . . . . . 131
Clock . . . . . . . . . . . . . . . . . . . . . . . . . 132
Power Outlets . . . . . . . . . . . . . . . . 133
Wireless Charging . . . . . . . . . . . . 134
Warning Lights, Gauges, and
Indicators Warning Lights, Gauges, and
Indicators . . . . . . . . . . . . . . . . . . . 137
Instrument Cluster . . . . . . . . . . . . 138
Speedometer . . . . . . . . . . . . . . . . . 142
Odometer . . . . . . . . . . . . . . . . . . . . . 142
Trip Odometer . . . . . . . . . . . . . . . . 142
Tachometer . . . . . . . . . . . . . . . . . . . 142
Fuel Gauge . . . . . . . . . . . . . . . . . . . 142
Engine Oil Pressure
Gauge . . . . . . . . . . . . . . . . . . . . . . 143
Engine Coolant Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 144 Transmission Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 145
Voltmeter Gauge . . . . . . . . . . . . . 145
Seat Belt Reminders . . . . . . . . . 146
Airbag Readiness Light . . . . . . . 147
Airbag On-Off Light . . . . . . . . . . . 147
Passenger Airbag Status
Indicator . . . . . . . . . . . . . . . . . . . . 149
Charging System Light . . . . . . . 149
Malfunction Indicator Lamp
(Check Engine Light) . . . . . . . . 150
Brake System Warning
Light . . . . . . . . . . . . . . . . . . . . . . . . 152
Antilock Brake System (ABS)
Warning Light . . . . . . . . . . . . . . . 152
Four-Wheel-Drive Light . . . . . . . 153
Tow/Haul Mode Light . . . . . . . . . 153
Hill Descent Control Light . . . . 153
Lane Departure Warning
(LDW) Light (2500/3500) . . . . 153
Lane Keep Assist (LKA) Light
(1500 Series) . . . . . . . . . . . . . . . 154
Vehicle Ahead Indicator . . . . . . 154
Traction Off Light . . . . . . . . . . . . . 154
StabiliTrak OFF Light . . . . . . . . . 154
Traction Control System (TCS)/
StabiliTrak Light . . . . . . . . . . . . . 155
Engine Coolant Temperature
Warning Light . . . . . . . . . . . . . . . 155
Tire Pressure Light . . . . . . . . . . . 156 Engine Oil Pressure Light
(Denali Only) . . . . . . . . . . . . . . . . 156
Low Fuel Warning Light . . . . . . 156
Security Light . . . . . . . . . . . . . . . . . 157
High-Beam On Light . . . . . . . . . . 157
Front Fog Lamp Light . . . . . . . . . 157
Lamps On Reminder . . . . . . . . . 157
Cruise Control Light . . . . . . . . . . 158
Door Ajar Light . . . . . . . . . . . . . . . 158
Information Displays Driver Information Center (DIC)
(Base Level Cluster) . . . . . . . . 158
Driver Information Center (DIC)
(Uplevel and Denali
Cluster) . . . . . . . . . . . . . . . . . . . . . 160
Vehicle Messages Vehicle Messages . . . . . . . . . . . . 164
Engine Power Messages . . . . . 164
Vehicle Speed Messages . . . . . 164
Vehicle Personalization Vehicle Personalization . . . . . . . 165
Universal Remote System Universal Remote System . . . . 172
Universal Remote System
Programming . . . . . . . . . . . . . . . 172
Universal Remote System
Operation . . . . . . . . . . . . . . . . . . . 174

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 137SERVICES; LOSS OF USE, DATA,
OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY
OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF
THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
Warning Lights,
Gauges, and
Indicators Warning lights and gauges can
signal that something is wrong
before it becomes serious enough
to cause an expensive repair or
replacement. Paying attention to the
warning lights and gauges could
prevent injury. Some warning lights come on briefly
when the engine is started to
indicate they are working. When
one of the warning lights comes on
and stays on while driving, or when
one of the gauges shows there may
be a problem, check the section that
explains what to do. Waiting to do
repairs can be costly and even
dangerous.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 143When the ignition is on, the fuel
gauge indicates about how much
fuel is left in the tank.
There is an arrow near the fuel
gauge pointing to the side of the
vehicle the fuel door is on.
When the indicator nears empty, the
low fuel light comes on. There still is
a little fuel left, but the vehicle
should be refueled soon.
Here are four things that some
owners ask about. None of these
show a problem with the fuel gauge:
.
At the service station, the fuel
pump shuts off before the gauge
reads full.
.
It takes a little more or less fuel
to fill up than the gauge
indicated. For example, the
gauge may have indicated the
tank was half full, but it actually
took a little more or less than
half the tank's capacity to fill
the tank.
.
The gauge moves a little while
turning a corner or speeding up. .
The gauge takes a few seconds
to stabilize after the ignition is
turned on, and goes back to
empty when the ignition is
turned off.
Engine Oil Pressure
Gauge
Metric, Standard Theme Shown English, Standard Theme Shown
The engine oil pressure gauge
shows the engine oil pressure
in kPa (kilopascals) or psi (pounds
per square inch) when the engine is
running.
Oil pressure can vary with engine
speed, outside temperature, coolant
temperature, and oil viscosity.
A reading outside the normal
operating range can be caused by a
dangerously low oil level or some
other problem causing low oil
pressure. Check the vehicle's oil as
soon as possible. A DIC message
may display. See Engine Oil 0 350 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 149
Passenger Airbag Status
Indicator If the vehicle has the passenger
sensing system, the overhead
console will have a passenger
airbag status indicator. See
Passenger Sensing System 0 86 for
important safety information.
United States
Canada and Mexico
When the vehicle is started, the
passenger airbag status indicator
will light ON and OFF, or the symbol
for on and off, for several seconds
as a system check. Then, after several more seconds, the status
indicator will light either ON or OFF,
or either the on or off symbol, to let
you know the status of the front
outboard passenger frontal airbag.
If the word ON or the on symbol is
lit on the passenger airbag status
indicator, it means that the front
outboard passenger frontal airbag is
allowed to inflate.
If the word OFF or the off symbol is
lit on the airbag status indicator, it
means that the passenger sensing
system has turned off the front
outboard passenger frontal airbag.
If, after several seconds, both status
indicator lights remain on, or if there
are no lights at all, there may be a
problem with the lights or the
passenger sensing system. See
your dealer for service.
{ Warning
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
(Continued) Warning (Continued) with the airbag system. To help
avoid injury to yourself or others,
have the vehicle serviced right
away. See Airbag Readiness
Light 0 147 for more information,
including important safety
information.
Charging System Light
The charging system light comes on
briefly when the ignition is turned
on, but the engine is not running, as
a check to show the light is working.
It should go out when the engine is
started.
If the light stays on, or comes on
while driving, there may be a
problem with the electrical charging

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
150 Instruments and Controls system. Have it checked by your
dealer. Driving while this light is on
could drain the battery.
When this light comes on, or is
flashing, the Driver Information
Center (DIC) also displays a
message.
If a short distance must be driven
with the light on, be sure to turn off
all accessories, such as the radio
and air conditioner.
Malfunction Indicator
Lamp (Check Engine
Light) This light is part of the vehicle ’ s
emission control on-board
diagnostic system. If this light is on
while the engine is running, a
malfunction has been detected and
the vehicle may require service. The
light should come on to show that it
is working when the ignition is on
and the engine is not running. See
Ignition Positions 0 256 . Malfunctions are often indicated by
the system before any problem is
noticeable. Being aware of the light
and seeking service promptly when
it comes on may prevent damage.
CautionIf the vehicle is driven continually
with this light on, the emission
control system may not work as
well, the fuel economy may be
lower, and the vehicle may not
run smoothly. This could lead to
costly repairs that might not be
covered by the vehicle warranty. CautionModifications to the engine,
transmission, exhaust, intake,
or fuel system, or the use of
replacement tires that do not
meet the original tire
specifications, can cause this light
to come on. This could lead to
costly repairs not covered by the
vehicle warranty. This could also
affect the vehicle ’ s ability to pass
an Emissions Inspection/
Maintenance test. See
Accessories and Modifications
0 343 .
If the light is flashing : A
malfunction has been detected that
could damage the emission control
system and increase vehicle
emissions. Diagnosis and service
may be required.
To help prevent damage, reduce
vehicle speed and avoid hard
accelerations and uphill grades.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 151If towing a trailer, reduce the
amount of cargo being hauled as
soon as possible.
If the light continues to flash, find a
safe place to park. Turn the vehicle
off and wait at least 10 seconds
before restarting the engine. If the
light is still flashing, follow the
previous guidelines and see your
dealer for service as soon as
possible.
If the light is on steady : A
malfunction has been detected.
Diagnosis and service may be
required.
Check the following:
.
A loose or missing fuel cap may
cause the light to come on. See
Filling the Tank 0 301 . A few
driving trips with the cap
properly installed may turn the
light off.
.
Poor fuel quality can cause
inefficient engine operation and
poor driveability, which may go
away once the engine is warmed
up. If this occurs, change the
fuel brand. It may require at least one full tank of the proper
fuel to turn the light off. See Fuel
0 299 .
If the light remains on, see your
dealer.
Emissions Inspection and
Maintenance Programs If the vehicle requires an Emissions
Inspection/Maintenance test, the
test equipment will likely connect to
the vehicle's Data Link
Connector (DLC).
The DLC is under the instrument
panel to the left of the steering
wheel. Connecting devices that are
not used to perform an Emissions
Inspection/Maintenance test or to
service the vehicle may affect
vehicle operation. See Add-On
Electrical Equipment 0 336 . See
your dealer if assistance is needed. The vehicle may not pass
inspection if:
.
The light is on when the engine
is running.
.
The light does not come on
when the ignition is on while the
engine is off.
.
Critical emission control systems
have not been completely
diagnosed. If this happens, the
vehicle would not be ready for
inspection and might require
several days of routine driving
before the system is ready for
inspection. This can happen if
the 12-volt battery has recently
been replaced or run down, or if
the vehicle has been recently
serviced.
See your dealer if the vehicle will
not pass or cannot be made ready
for the test.