2021 CHEVROLET BLAZER check engine light

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Instruments and Controls 101
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 fuel funnel adapter,
make sure that it has been removed. See
“Filling the Tank with a Portable Gas Can”
under Filling the Tank 0240. 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 Recommended Fuel 0239.
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
0 252. 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 in Service Mode.
.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.
Brake System Warning Light
MetricEnglish
This light should come on briefly when the
vehicle is turned on. If it does not come on
then, have it fixed so it will be ready to
warn you if there is a problem.
If the light comes on and stays on at start
up, there is a brake problem. Have the brake
system inspected right away.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Instruments and Controls 105
SeeTraction Control/Electronic Stability
Control 0213.
Engine Coolant Temperature
Warning Light
This light comes on briefly while starting
the vehicle.
If it does not, have the vehicle serviced by
your dealer. If the system is working
normally the indicator light goes off.
Caution
The engine coolant temperature warning
light indicates that the vehicle has
overheated. Driving with this light on can
damage the engine and it may not be
covered by the vehicle warranty. See
Engine Overheating 0271.
The engine coolant temperature warning
light comes on when the engine has
overheated. If this happens, pull over and turn off the
engine as soon as possible. See
Engine
Overheating 0271.
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.
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. See Tire Pressure
0 294. 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
0 297.
Engine Oil Pressure Light
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
Driver Information Center (DIC) message
indicates oil pressure outside the normal
operating range, check the vehicle's oil as
soon as possible.
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
(Continued)

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
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-
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.