check engine light CHEVROLET TAHOE 2018 Owner's Manual

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
56 Keys, Doors, and Windows
When 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 Breakers0325.
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
(Key Access) 030 orKeys (Keyless
Access) 033. 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
{Warning
A 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.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
142 Instruments and Controls
THIS SOFTWARE IS PROVIDED
BY THE COPYRIGHT HOLDERS
AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED
WARRANTIES OF
MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT
SHALL THE COPYRIGHT HOLDER
OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL,
EXEMPLARY, OR
CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED
TO, PROCUREMENT OF
SUBSTITUTE GOODS OR
SERVICES; 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 OFTHE 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.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
Instruments and Controls 149
English
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.
On some models, the oil pump will
vary engine oil pressure according
to engine needs. Oil pressure may
change quickly as the engine speed
or load varies. This is normal. If the
oil pressure warning light or Driver
Information Center (DIC) message indicates oil pressure outside the
normal operating range, check the
vehicle's oil as soon as possible.
See
Engine Oil 0297.
Caution
Lack of proper engine oil
maintenance can damage the
engine. Driving with the engine oil
low can also damage the engine.
The repairs would not be covered
by the vehicle warranty. Check
the oil level as soon as possible.
Add oil if required, but if the oil
level is within the operating range
and the oil pressure is still low,
have the vehicle serviced. Always
follow the maintenance schedule
for changing engine oil.
Engine Coolant
Temperature Gauge
Metric

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
Instruments and Controls 153
Warning (Continued)
with the airbag system. To help
avoid injury to yourself or others,
have the vehicle serviced right
away. SeeAirbag Readiness
Light 0151 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 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
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
with the engine not running for Key
Access or in Service Mode for
Keyless Access.
See
Ignition Positions (Key Access)
0 219 orIgnition Positions (Keyless
Access) 0217.
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.
Caution
If 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.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
154 Instruments and Controls
Caution
Modifications 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
0291.
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. If 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:
. If fuel has been added to the
vehicle using the capless funnel
adapter, make sure that it has
been removed. See “Filling the
Tank with a Portable Gas Can”
under Filling the Tank 0269.
The diagnostic system can
detect if the adapter has been
left installed in the vehicle,
allowing fuel to evaporate into the atmosphere. A few driving
trips with the adapter removed
may turn off the light.
. 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
0 266.
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).

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
158 Instruments and Controls
dealer. If the system is working
normally, the indicator light then
turns off.
The traction off light comes on when
the Traction Control System (TCS)
has been turned off by pressing and
releasing the TCS/StabiliTrak
button.
This light and the StabiliTrak OFF
light come on when StabiliTrak is
turned off.
If the TCS is off, wheel spin is not
limited. Adjust driving accordingly.
SeeTraction Control/Electronic
Stability Control 0242.
StabiliTrak OFF Light
This light comes on briefly while
starting the engine. If it does not,
have the vehicle serviced by your
dealer. This light comes on when the
StabiliTrak system is turned off.
If StabiliTrak is off, the Traction
Control System (TCS) is also off.
If StabiliTrak and TCS are off, the
system does not assist in controlling
the vehicle. Turn on the TCS and
the StabiliTrak systems, and the
warning light turns off.
See
Traction Control/Electronic
Stability Control 0242.
Traction Control System
(TCS)/StabiliTrak Light
This light comes on briefly when the
engine is started.
If the light does not come on, have
the vehicle serviced by your dealer.
If the system is working normally,
the indicator light turns off. If the light is on and not flashing, the
TCS and potentially the StabiliTrak
system have been disabled.
A Driver Information Center (DIC)
message may display. Check the
DIC messages to determine which
feature(s) is no longer functioning
and whether the vehicle requires
service.
If the light is on and flashing, the
TCS and/or the StabiliTrak system
is actively working.
See
Traction Control/Electronic
Stability Control 0242.
Tire Pressure Light
For vehicles with the Tire Pressure
Monitor System (TPMS), this light
comes on briefly when the engine is
started. It provides information
about tire pressures and the TPMS.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
Instruments and Controls 159
When the Light Is On Steady
This indicates that one or more of
the tires are significantly
underinflated.
A Driver Information Center (DIC)
tire pressure message may also
display. Stop as soon as possible,
and inflate the tires to the pressure
value shown on the Tire and
Loading Information label. SeeTire
Pressure 0343.
When the Light Flashes First and
Then Is On Steady
If the light flashes for about a minute
and then stays on, there may be a
problem with the TPMS. If the
problem is not corrected, the light
will come on at every ignition cycle.
See Tire Pressure Monitor
Operation 0346.Low Fuel Warning Light
This light is near the fuel gauge and
comes on briefly when the ignition is
turned on as a check to show it is
working.
It also comes on when the fuel tank
is low on fuel. The light turns off
when fuel is added. If it does not,
have the vehicle serviced.
Security Light
The security light should come on
briefly as the engine is started. If it
does not come on, have the vehicle serviced by your dealer. If the
system is working normally, the
indicator light turns off.
If the light stays on and the engine
does not start, there could be a
problem with the theft-deterrent
system. See
Immobilizer Operation
0 55.
High-Beam On Light
This light comes on when the
high-beam headlamps are in use.
See Headlamp High/Low-Beam
Changer 0183.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
242 Driving and Operating
Ride Control Systems
Traction Control/
Electronic Stability
Control
System Operation
The vehicle has a Traction Control
System (TCS) and StabiliTrak®, an
electronic stability control system.
These systems help limit wheel spin
and assist the driver in maintaining
control, especially on slippery road
conditions.
TCS activates if it senses that 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 activates when the
vehicle senses a difference between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak selectively applies
braking pressure to any one of the
vehicle wheel brakes to assist the
driver in keeping the vehicle on the intended path. Trailer Sway Control
(TSC) is also on automatically when
the vehicle is started. See
Trailer
Sway Control (TSC) 0286.
If cruise control is being used and
traction control or StabiliTrak 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 0211
and “Turning the Systems Off and
On” later in this section. When the transfer case is in
Four-Wheel Drive Low, the stability
system is automatically disabled,
g
comes on, and the appropriate
message will appear on the DIC.
Both traction control and StabiliTrak
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 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

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
286 Driving and Operating
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.
SERVICE TRAILER BRAKE
SYSTEM: This message will display
when there is a problem with the
ITBC system. If this message
continues over multiple ignition
cycles, there is a problem with the
ITBC system. Have the vehicle
serviced.
If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM 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 ignition off. Check the
wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, 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 have a
Trailer Sway Control (TSC) feature.
Trailer sway is unintended
side-to-side motion of a trailer while
being towed. 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 the vehicle
is equipped with the Integrated
Trailer Brake Control (ITBC) system,
and the trailer has the electric
actuated brake system, StabiliTrak
may also apply the trailer brakes.
If TSC is enabled, the Traction
Control System (TCS)/StabiliTrak
warning light will flash on theinstrument cluster. Vehicle speed
must be reduced. If trailer sway
continues, StabiliTrak can reduce
engine torque to help slow the
vehicle. See
Traction Control/
Electronic Stability Control 0242.
{Warning
Even if the vehicle is equipped
with TSC, trailer sway could result
in loss of control and the vehicle
could crash. If excessive trailer
sway is detected, slow down to a
safe speed. Check the trailer and
vehicle to help correct possible
causes. These could include an
improperly or overloaded trailer,
unrestrained cargo, improper
trailer hitch configuration,
excessive vehicle-trailer speed,
or improperly inflated or incorrect
vehicle or trailer tires. See Towing
Equipment 0278 for trailer ratings
and hitch setup
recommendations.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
Vehicle Care 289
Vehicle Care
General Information
General Information . . . . . . . . . . 290
California Proposition65 Warning . . . . . . . . . . . . . . . . . 291
California Perchlorate Materials Requirements . . . . . 291
Accessories and Modifications . . . . . . . . . . . . . . . . 291
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 292
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 292
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 293
Engine Oil . . . . . . . . . . . . . . . . . . . . 297
Engine Oil Life System . . . . . . . 299
Automatic Transmission Fluid (6-Speed Transmission) . . . . . 301
Automatic Transmission Fluid (10-Speed Transmission) . . . 304
Engine Air Cleaner/Filter . . . . . . 304
Cooling System . . . . . . . . . . . . . . 305
Engine Overheating . . . . . . . . . . 309
Engine Fan . . . . . . . . . . . . . . . . . . . 310
Power Steering Fluid . . . . . . . . . 311
Washer Fluid . . . . . . . . . . . . . . . . . 311 Brakes . . . . . . . . . . . . . . . . . . . . . . . 312
Brake Fluid . . . . . . . . . . . . . . . . . . . 312
Battery - North America . . . . . . 314
Four-Wheel Drive . . . . . . . . . . . . . 314
Front Axle . . . . . . . . . . . . . . . . . . . . 315
Rear Axle . . . . . . . . . . . . . . . . . . . . 315
Starter Switch Check . . . . . . . . . 316
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 317
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 317
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 317
Wiper Blade Replacement . . . . 318
Glass Replacement . . . . . . . . . . 319
Windshield Replacement . . . . . 319
Gas Strut(s) . . . . . . . . . . . . . . . . . . 319
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 320
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 321
Halogen Bulbs . . . . . . . . . . . . . . . . 321
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 321
LED Lighting . . . . . . . . . . . . . . . . . 321
Headlamps . . . . . . . . . . . . . . . . . . . 321
Fog Lamps . . . . . . . . . . . . . . . . . . . 322
Front Turn Signal Lamps . . . . . 322 Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 322
License Plate Lamp . . . . . . . . . . 324
Electrical System
Electrical System Overload . . . 324
Fuses and Circuit Breakers . . . 325
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 325
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . . . 330
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 333
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 335
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 336
All-Season Tires . . . . . . . . . . . . . . 337
Winter Tires . . . . . . . . . . . . . . . . . . 337
Low-Profile Tires . . . . . . . . . . . . . 338
All-Terrain Tires . . . . . . . . . . . . . . . 338
Tire Sidewall Labeling . . . . . . . . 338
Tire Designations . . . . . . . . . . . . . 339
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 340
Tire Pressure . . . . . . . . . . . . . . . . . 343
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 344