check engine CHEVROLET BLAZER 2021 User Guide

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
106 Instruments and Controls
Caution (Continued)
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.
This 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 light comes on and stays on, it means
that oil is not flowing through the engine
properly. The vehicle could be low on oil
and might have some other system
problem. See your dealer.
Low Fuel Warning Light
A Low Fuel Warning Light near the fuel
gauge comes on briefly when the ignition is
turned on as a check to show it is working.
It also comes on when the fuel gauge
indicator nears empty. 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 024.
High-Beam On Light
This light comes on when the high-beam
headlamps are in use. See Headlamp High/
Low-Beam Changer 0122.
IntelliBeam Light
This light comes on when the IntelliBeam
system, if equipped, is enabled. See Exterior
Lamp Controls 0121.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
110 Instruments and Controls
Driver Assistance :If equipped, shows
information for Lane Keep Assist (LKA), Lane
Departure Warning (LDW), and Forward
Collision Alert (FCA).
Economy Trend : Shows history of the
Average Fuel Economy from the last 50 km
(30 mi). Each bar represents about 5 km
(3 mi) of driving. During driving the bars will
shift to always reflect the most recent
distance on the right side. Press the
thumbwheel to open the menu while this
display is active to clear the graph. Select
yes or no and press the thumbwheel.
Timer : This display can be used as a timer.
To start the timer, press the thumbwheel to
open the menu while this display is active.
Use
yorzto select Start Timer or Reset.
Press the thumbwheel. To stop the timer,
press the thumbwheel while this display is
active. The display will show the amount of
time that has passed since the timer was
last reset.
Speed Limit : Shows sign information, which
comes from a roadway database in the
onboard navigation, if equipped. The sign
will show “− −”when there is no detected
speed limit or the system is unavailable. Press the thumbwheel while this display is
active to toggle Speed Limit sign on or off.
Speed limit signs in your vehicle display
may vary from actual road speed depending
on the version of your current
navigation map.
Battery Voltage :
Displays the current
battery voltage, if equipped. Battery voltage
changes are normal while driving. See
Charging System Light 0100. If there is a
problem with the battery charging system, a
DIC will display a message.
Oil Pressure : Oil pressure is displayed in
either kilopascal (kPa) or in pounds per
square inch (psi). Oil pressure can vary with
engine speed, outside 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
DIC message indicates oil pressure outside
the normal operating range, check the
vehicle's oil as soon as possible.
Coolant Temperature : Displays the coolant
temperature in degrees Celsius (°C) or
degrees Fahrenheit (°F).
Driver Information Center (DIC)
(Uplevel)
The DIC displays are shown in the center of
the instrument cluster in the Info app.
See Instrument Cluster (Base and Midlevel)
0 90 or
Instrument Cluster (Uplevel) 093. The
displays show the status of many vehicle
systems.
SorT: Press to move left or right
between the interactive display zones in the
cluster. Press the thumbwheel to select.
yorz: Use the thumbwheel to scroll up
or down in a list. Press the thumbwheel to
select.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
194 Driving and Operating
This affects steering, accelerating, and
braking. Drive at a reduced speed and avoid
sharp turns or abrupt maneuvers.
Traction is reduced on hard packed snow
and ice and it is easy to lose control. Reduce
vehicle speed when driving on hard packed
snow and ice.
{Warning
Driving on frozen lakes, ponds, or rivers
can be dangerous. Ice conditions vary
greatly and the vehicle could fall through
the ice; you and your passengers could
drown. Drive your vehicle on safe
surfaces only.
Driving in Water
{Warning
Driving through rushing water can be
dangerous. Deep water can sweep your
vehicle downstream and you and your
passengers could drown. If it is only
shallow water, it can still wash away the
ground from under your tires. Traction
could be lost, and the vehicle could roll
over. Do not drive through rushing water.
Caution
Do not drive through standing water if it
is deep enough to cover the wheel hubs,
axles, or exhaust pipe. Deep water can
damage the axle and other vehicle parts.
If the standing water is not too deep, drive
through it slowly. At faster speeds, water
can get into the engine and cause it to stall.
Stalling can occur if the exhaust pipe is
under water. Do not turn off the ignition
when driving through water. If the exhaust
pipe is under water, the engine will not
start. When going through water, the brakes
get wet, and it might take longer to stop.
See Driving on Wet Roads 0194.
After Off-Road Driving
Remove any brush or debris that has
collected on the underbody or chassis,
or under the hood. These accumulations can
be a fire hazard.
After operation in mud or sand, have the
brake linings cleaned and checked. These
substances can cause glazing and uneven
braking. Check the body structure, steering,
suspension, wheels, tires, and exhaust
system for damage and check the fuel lines
and cooling system for any leakage. More frequent maintenance service is
required. See
Maintenance Schedule 0332.
Driving on Wet Roads
Rain and wet roads can reduce vehicle
traction and affect your ability to stop and
accelerate. Always drive slower in these
types of driving conditions and avoid driving
through large puddles and deep-standing or
flowing water.
{Warning
Wet brakes can cause crashes. They
might not work as well in a quick stop
and could cause pulling to one side. You
could lose control of the vehicle.
After driving through a large puddle of
water or a car/vehicle wash, lightly apply
the brake pedal until the brakes work
normally.
Flowing or rushing water creates strong
forces. Driving through flowing water
could cause the vehicle to be carried
away. If this happens, you and other
vehicle occupants could drown. Do not
(Continued)

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Driving and Operating 195
Warning (Continued)
ignore police warnings and be very
cautious about trying to drive through
flowing water.
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 0287.
.Turn off cruise control.
.Activate All-Wheel Drive (AWD) mode. See
Driver Mode Control 0214.
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, 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
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.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
204 Driving and Operating
may have an internal thermostat in the cord
which will prevent engine heater operation
at temperatures above 0 °F (−18 °C).
{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 isdamaged, 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 bumper.
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
(Continued)
Warning (Continued)
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.
.Before starting the vehicle, unplug the
cord. Keep the cord away from any
moving parts.
5. Before starting the engine, be sure to unplug and store the cord as it was
before to keep it away from moving
engine parts. If you do not, it could be
damaged.
The length of time the heater should remain
plugged in depends on several factors. Ask a
dealer in the area where you will be parking
the vehicle for the best advice on this.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
210 Driving and Operating
speed is not reduced within the time
allowed, the lower gear range shift will not
be completed. You must further slow the
vehicle, then press−(Minus) to the desired
lower gear range.
Automatic Engine Grade Braking is not
available when the ERS is active. It is
available in D (Drive) for both normal driving
and Tow/Haul Mode. While using the ERS,
cruise control and the Tow/Haul Mode can
be used. See “Tow/Haul Mode” following.
Tow/Haul Mode
This feature can assist when towing or
hauling a heavy load. See Driver Mode
Control 0214 to activate Tow/Haul Mode.
Drive Systems
All-Wheel Drive
Vehicles with this feature can operate in
All-Wheel Drive (AWD) Mode.
Turn the knob to4to select AWD.
See Driver Mode Control 0214.
When operated in two-wheel drive, the
vehicle will deliver power to the front
wheels only and may provide better fuel
economy.
When using a compact spare tire on an
AWD vehicle, the system automatically
detects the compact spare and reduces AWD
performance to protect the system. To
restore full AWD operation and prevent
excessive wear on the system, replace the
compact spare with a full-size tire as soon as
possible. See Compact Spare Tire 0317.
Brakes
Electric Brake Boost
Vehicles equipped with electric brake boost
have hydraulic brake circuits that are
electronically controlled when the brake
pedal is applied during normal operation.
The system performs routine tests and turns
off within a few minutes after the vehicle is
turned off. Noise may be heard during this
time. If the brake pedal is pressed during
the tests or when the electric brake boost
system is off, a noticeable change in pedal
force and travel may be felt. This is normal.
Antilock Brake System (ABS)
The Antilock Brake System (ABS) helps
prevent a braking skid and maintain steering
while braking hard.
ABS performs a system check when the
vehicle is first driven. A momentary motor
or clicking noise may be heard while this
test is going on, and the brake pedal may
move slightly. This is normal.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Driving and Operating 213
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). 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. TCS also applies torque to the
non-spinning wheel to increase traction and
acceleration.
StabiliTrak/ESC activates when the vehicle
senses a difference between the intended
path and the direction the vehicle is actuallytraveling. StabiliTrak/ESC selectively applies
braking pressure to any one of the vehicle
wheel brakes to assist the driver in keeping
the vehicle on the intended path.
If cruise control is being used and TCS or
StabiliTrak/ESC begins to limit wheel spin,
cruise control will disengage. Cruise control
may be turned back on when road
conditions allow. TCS and StabiliTrak/ESC will
automatically turn on when cruise control
is set.
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 0196 and “Turning the
Systems Off and On” later in this section.
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 may display in the
Driver Information Center (DIC), and
d
comes 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.
4. Drive the vehicle.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Driving and Operating 243
If the transmission downshifts too often,
a lower gear may be selected using
Manual Mode. SeeManual Mode0209.
If equipped, Driver Assistance Systems must
be turned off when towing a trailer:
.Adaptive Cruise Control (ACC)
.Lane Keep Assist (LKA)
.Park Assist
.Reverse Automatic Braking (RAB)
If equipped, the following driver assistance
features should be turned to alert or off
when towing a trailer:
.Automatic Emergency Braking (AEB)
.Intelligent Brake Assist (IBA)
.Front Pedestrian Braking (FPB)
If equipped with Lane Change Alert (LCA),
the LCA detection zones that extend back
from the side of the vehicle do not move
further back when a trailer is towed. Use
caution while changing lanes when towing a
trailer.
If equipped with Rear Cross Traffic Alert
(RCTA), use caution while backing up when
towing a trailer, as the RCTA detection zones
that extend out from the back of the vehicle
do not move further back when a trailer is
towed.
{Warning
To prevent serious injury or death from
carbon monoxide (CO), when towing a
trailer:
.Do not drive with the liftgate, trunk/
hatch, or rear-most window open.
.Fully open the air outlets on or under
the instrument panel.
.Adjust the climate control system to a
setting that brings in only outside air.
See “Climate Control Systems” in the
Index.
For more information about carbon
monoxide, see Engine Exhaust 0207.
Towing a trailer requires experience. The
combination of the vehicle and trailer is
longer and not as responsive as the vehicle
itself. Get used to the handling and braking
of the combination by driving on a level
road surface before driving on public roads.
The trailer structure, the tires, and the
brakes must all be rated to carry the
intended cargo. Inadequate trailer
equipment can cause the combination to
operate in an unexpected or unsafe manner. Before driving, inspect all trailer hitch parts
and attachments, safety chains, electrical
connectors, lamps, tires, and mirrors. See
Towing Equipment
0248. If the trailer has
electric brakes, start the combination
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

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Driving and Operating 245
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
.Start the engine.
.Shift into a gear.
.Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
The vehicle needs service more often when
used to tow trailers. See the Maintenance
Schedule 0332. It is especially important to
check the engine oil, axle lubricant, belts,
cooling system, and brake system before
and during each trip.
Check periodically 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 0271.
Trailer Towing
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.
Trailer Weight
{Warning
Never exceed the towing capacity for
your vehicle. Safe trailering requires monitoring the
weight, speed, altitude, road grades, outside
temperature, dimensions of the front of the
trailer, and how frequently the vehicle is
used to tow a trailer.
Trailer Weight Ratings
When towing a trailer, the combined weight
of the vehicle, vehicle contents, trailer, and
trailer contents must be below all of the
maximum weight ratings for the vehicle,
including:
.GCWR: Gross Combined Weight Rating
.GVWR: Gross Vehicle Weight Rating
.Maximum Trailer Weight Rating
.Maximum Trailer Tongue Weight Rating
See “Weight-Distributing Hitch Adjustment”
under Towing Equipment 0248 to
determine if equalizer bars are required to
obtain the maximum trailer weight rating.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
250 Driving and Operating
attempt to tap into your vehicle's hydraulic
brake system. If you do, both the vehicle
antilock brakes and the trailer brakes may
not function, which could result in a crash.
Trailer Wiring Harness
Basic Trailer Wiring
The trailer wiring harness, with a seven-pin
connector, is at the rear of the vehicle and
is tied to the vehicle's frame. The harness
requires the installation of a trailer
connector, which is available through your
dealer.
Use only a round, seven-wire connector with
flat blade terminals meeting SAE J2863
specifications for proper electrical
connectivity.
The seven-wire harness contains the
following trailer circuits:
.Yellow: Left Stop/Turn Signal
.Green: Right Stop/Turn Signal
.Brown: Tail/Parking Lamps
.White: Trailer Ground
.Red: Stop Lamp Supply Voltage
.Black: Back Up Lamp Supply Voltage
.Blue: Service BrakesThe fuse for the electric trailer brake circuit
is in the engine compartment fuse block,
but the wires may not be connected. They
should be connected by your dealer or a
qualified service center. To control electric
trailer brakes, a trailer brake controller needs
to be installed on the vehicle by your dealer
or a qualified service center. See electric
brake control wiring provisions.
If a battery outside the vehicle is being
charged, place the vehicle in Tow/Haul
Mode. This will boost the vehicle system
voltage and properly charge the battery.
If the trailer is too light for Tow/Haul Mode,
turn on the non-HID only headlamps as a
second way to boost the vehicle system
voltage and charge the battery.
Electric Trailer Brake Control Wiring
Provisions
Wiring provisions for an aftermarket electric
trailer brake controller are included with the
vehicle as part of the trailer wiring package.
The harness contains the following circuits:
These wiring provisions for an electric trailer
brake controller are included with the
vehicle as part of the trailer wiring package.
The body harness, inside the front driver
side instrument panel, contains blunt cut wires below the headlamp switch for the
electric trailer brake controller. The harness
contains the following wires:
.Blue: Electric Trailer Brakes
.Blue: Battery Feed
.White/Blue: Brake Apply Signal
.Black: Ground
Refer to the aftermarket electric trailer brake
controller owner's manual to determine wire
color coding of the electric trailer brake
controller. The wire colors on the brake
controller may be different from the vehicle.
The electric trailer brake controller should be
installed by your dealer or a qualified
service center.
Trailer Lamps
Always check all trailer lamps are working at
the beginning of each trip, and periodically
on longer trips.
Turn Signals When Towing a Trailer
When properly connected, the trailer turn
signals will illuminate to indicate the vehicle
is turning, changing lanes, or stopping.
When towing a trailer, the arrows on the
instrument cluster will illuminate even if the
trailer is not properly connected or the bulbs
are burned out.