2021 CHEVROLET BLAZER check engine light

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Driving and Operating 251
Tow/Haul Mode
For instructions on how to enter Tow/Haul
Mode, seeDriver Mode Control 0214.
Tow/Haul assists when pulling a heavy
trailer or a large or heavy load. See Tow/
Haul Mode 0210.
Tow/Haul Mode is designed to be most
effective when the vehicle and trailer
combined weight is at least 75% of the
vehicle's Gross Combined Weight Rating
(GCWR). See “Weight of the Trailer” under
Trailer Towing 0245. Tow/Haul Mode is
most useful when towing a heavy trailer or
carrying a large or heavy load:
.Through rolling terrain.
.In stop-and-go traffic.
.In busy parking lots.
Operating the vehicle in Tow/Haul Mode
when lightly loaded or not towing will not
cause damage; however, it is not
recommended and may result in unpleasant
engine and transmission driving
characteristics and reduced fuel economy.
Trailer Sway Control (TSC)
Vehicles with StabiliTrak/Electronic Stability
Control (ESC) have a Trailer Sway Control
(TSC) feature. Trailer sway is unintended side-to-side motion of a trailer while towing.
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 equipped with the Integrated Trailer Brake
Control (ITBC) system, and the trailer has an
electric brake system, StabiliTrak/ESC may
also apply the trailer brakes.
If TSC is enabled, the Traction Control
System (TCS)/StabiliTrak light will flash on
the instrument cluster. Reduce vehicle speed
by gradually removing your foot from the
accelerator. If trailer sway continues,
StabiliTrak/ESC can reduce engine torque to
help slow the vehicle. TSC will not function
if StabiliTrak/ESC is turned off. See
Traction
Control/Electronic Stability Control 0213.
{Warning
Trailer sway can result in a crash and in
serious injury or death, even if the
vehicle is equipped with TSC.
If the trailer begins to sway, reduce
vehicle speed by gradually removing your
foot from the accelerator. Then pull over
to check the trailer and vehicle to help
correct possible causes, including an
improperly or overloaded trailer,
unrestrained cargo, improper trailer hitch
configuration, or improperly inflated or
incorrect vehicle or trailer tires. See
Towing Equipment 0248 for trailer
ratings and hitch setup recommendations.
Trailer Tires
Special Trailer (ST) tires differ from vehicle
tires. Trailer tires are designed with stiff
sidewalls to help prevent sway and to
support heavy loads. These features can
make it difficult to determine if the trailer
tire pressures are low only based on a visual
inspection.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
252 Driving and Operating
Always check all trailer tire pressures before
each trip when the tires are cool. Low trailer
tire pressure is a leading cause of trailer tire
blowouts.
Trailer tires deteriorate over time. The trailer
tire sidewall will show the week and year
the tire was manufactured. Many trailer tire
manufacturers recommend replacing tires
more than six years old.
Overloading is another leading cause of
trailer tire blowouts. Never load your trailer
with more weight than the tires are
designed to support. The load rating is on
the trailer tire sidewall.
Always know the maximum speed rating for
the trailer tires before driving. This may be
significantly lower than the vehicle tire
speed rating. The speed rating may be on
the trailer tire sidewall. If the speed rating is
not shown, the default trailer tire speed
rating is 105 km/h (65 mph).Conversions and Add-Ons
Add-On Electrical Equipment
{Warning
The Data Link Connector (DLC) is used for
vehicle service and Emission Inspection/
Maintenance testing. SeeMalfunction
Indicator Lamp (Check Engine Light) 0100
. A device connected to the DLC —such
as an aftermarket fleet or driver-behavior
tracking device —may interfere with
vehicle systems. This could affect vehicle
operation and cause a crash. Such devices
may also access information stored in the
vehicle’s systems.
Caution
Some electrical equipment can damage
the vehicle or cause components to not
work and would not be covered by the
vehicle warranty. Always check with your
dealer before adding electrical equipment.
Add-on equipment can drain the vehicle's
12-volt battery, even if the vehicle is not
operating.
The vehicle has an airbag system. Before
attempting to add anything electrical to the
vehicle, see Servicing the Airbag-Equipped
Vehicle 058 and
Adding Equipment to the Airbag-Equipped
Vehicle 059.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Vehicle Care 253
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 254
California Proposition 65 Warning . . . . . 254
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . 254
Accessories and Modifications . . . . . . . . . 254
Vehicle Checks
Doing Your Own Service Work . . . . . . . . . 255
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Engine Compartment Overview . . . . . . . . 257
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Engine Oil Life System . . . . . . . . . . . . . . . . 264
Automatic Transmission Fluid . . . . . . . . . 265
Engine Air Filter Life System . . . . . . . . . . 265
Engine Air Cleaner/Filter . . . . . . . . . . . . . . 265
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 267
Engine Overheating . . . . . . . . . . . . . . . . . . . . 271
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Battery - North America . . . . . . . . . . . . . . . 274
All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . . 275
Automatic Transmission Shift Lock Control Function Check . . . . . . . . . . . . . . 275
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
Wiper Blade Replacement . . . . . . . . . . . . . 276 Windshield Replacement . . . . . . . . . . . . . . . 277
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 278
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 278
High Intensity Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Back-Up Lamps . . . . . . . . . . . . . . . . . . . . . . . . 278
Electrical System
High Voltage Devices and Wiring . . . . . . 279
Electrical System Overload . . . . . . . . . . . . 279
Fuses and Circuit Breakers . . . . . . . . . . . . 280
Engine Compartment Fuse Block . . . . . . 280
Instrument Panel Fuse Block . . . . . . . . . . 284
Rear Compartment Fuse Block . . . . . . . . . 285
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . 288
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Summer Tires . . . . . . . . . . . . . . . . . . . . . . . . . 289
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 289
Tire Designations . . . . . . . . . . . . . . . . . . . . . . 291
Tire Terminology and Definitions . . . . . . 292
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 294
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 Tire Pressure Monitor System . . . . . . . . . 296
Tire Pressure Monitor Operation . . . . . . 297
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . 300
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 300
When It Is Time for New Tires . . . . . . . . 301
Buying New Tires . . . . . . . . . . . . . . . . . . . . . 302
Different Size Tires and Wheels . . . . . . . 303
Uniform Tire Quality Grading . . . . . . . . . 303
Wheel Alignment and Tire Balance . . . . 305
Wheel Replacement . . . . . . . . . . . . . . . . . . . 305
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 306
Tire Sealant and Compressor Kit . . . . . . . 307
Storing the Tire Sealant and
Compressor Kit . . . . . . . . . . . . . . . . . . . . . . . 313
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . . 313
Compact Spare Tire . . . . . . . . . . . . . . . . . . . . 317
Jump Starting
Jump Starting - North America . . . . . . . . 318
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . . . . . . 320
Recreational Vehicle Towing . . . . . . . . . . . 321
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Vehicle Care 319
1. Discharged Battery Positive (+)Terminal
2. Discharged Battery Remote Negative (–) Terminal
3. Good Battery Negative (–) Terminal
4. Good Battery Positive (+) Terminal
The jump start positive (+) terminal (1) and
the negative remote negative terminal (2)
for the discharged battery are on the driver
side of the vehicle.
The jump start positive (+) terminal (4) and
negative (-) terminal (3) are on the battery
of the vehicle providing the jump start.
1. Check the other vehicle. It must have a 12-volt battery with a negative ground
system.
Caution
If the other vehicle does not have a
12-volt system with a negative ground,
both vehicles can be damaged. Only use
a vehicle that has a 12-volt system with a
negative ground for jump starting.
2. Position the two vehicles so that they are not touching.
3. Set the parking brake firmly and put the shift lever in P (Park) with an automatic
transmission, or Neutral with a manual
transmission. See Shifting Into Park
0 205.
Caution
If any accessories are left on or plugged
in during the jump starting procedure,
they could be damaged. The repairs
would not be covered by the vehicle
warranty. Whenever possible, turn off or
unplug all accessories on either vehicle
when jump starting.
4. Turn the ignition off. Turn off all lights and accessories in both vehicles, except
the hazard warning flashers if needed.
{Warning
An electric fan can start up even when
the engine is not running and can injure
you. Keep hands, clothing, and tools
away from any underhood electric fan.
{Warning
Using a match near a battery can cause
battery gas to explode. People have been
hurt doing this, and some have been
blinded. Use a flashlight if you need
more light.
Battery fluid contains acid that can burn
you. Do not get it on you. If you
accidentally get it in your eyes or on
your skin, flush the place with water and
get medical help immediately.
{Warning
Fans or other moving engine parts can
injure you badly. Keep your hands away
from moving parts once the engine is
running.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Vehicle Care 325
.Always dilute a concentrated cleaner
according to the manufacturer’s
instructions.
.Do not use cleaners that are not intended
for automotive use.
.Use a nonabrasive wax on the vehicle
after washing to protect and extend the
molding finish.
Cleaning Exterior Lamps/Lenses,
Emblems, Decals, and Stripes
Use only lukewarm or cold water, a soft
cloth, and a car washing soap to clean
exterior lamps, lenses, emblems, decals, and
stripes. Follow instructions under "Washing
the Vehicle" previously in this section.
Lamp covers are made of plastic, and some
have a UV protective coating. Do not clean
or wipe them when dry.
Do not use any of the following on lamp
covers:
.Abrasive or caustic agents
.Washer fluids and other cleaning agents
in higher concentrations than suggested
by the manufacturer.
.Solvents, alcohols, fuels, or other harsh
cleaners.
.Ice scrapers or other hard items.
.Aftermarket appearance caps or covers
while the lamps are illuminated, due to
excessive heat generated.
Caution
Failure to clean lamps properly can cause
damage to the lamp cover that would
not be covered by the vehicle warranty.
Caution
Using wax on low gloss black finish
stripes can increase the gloss level and
create a non-uniform finish. Clean low
gloss stripes with soap and water only.
Air Intakes
Clear debris from the air intakes, between
the hood and windshield, when washing the
vehicle.
Shutter System
The vehicle may have a shutter system
designed to help improve fuel economy.
Keep the shutter system clear of debris,
snow and ice. If the check engine light is
activated, please check to see if the shutter
system is clear of debris, snow or ice.
Windshield and Wiper Blades
Clean the outside of the windshield with
glass cleaner.
Clean rubber blades using a lint-free cloth or
paper towel soaked with windshield washer
fluid or a mild detergent. Wash the
windshield thoroughly when cleaning the

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
338 Service and Maintenance
.Trained dealer technicians have the
diagnostic equipment to test the battery
and ensure that the connections and
cables are corrosion-free.
Belts
.Belts may need replacing if they squeak
or show signs of cracking or splitting.
.Trained dealer technicians have access to
tools and equipment to inspect the belts
and recommend adjustment or
replacement when necessary.
Brakes
Brakes stop the vehicle and are crucial to
safe driving.
.Signs of brake wear may include chirping,
grinding, or squealing noises, or difficulty
stopping.
.Trained dealer technicians have access to
tools and equipment to inspect the brakes
and recommend quality parts engineered
for the vehicle. Fluids
Proper fluid levels and approved fluids
protect the vehicle’s systems and
components. See
Recommended Fluids and
Lubricants 0340 for GM approved fluids.
.Engine oil and windshield washer fluid
levels should be checked at every fuel fill.
.Instrument cluster lights may come on to
indicate that fluids may be low and need
to be filled.
Hoses
Hoses transport fluids and should be
regularly inspected to ensure that there are
no cracks or leaks. With a multi-point
inspection, your dealer can inspect the hoses
and advise if replacement is needed.
Lamps
Properly working headlamps, taillamps, and
brake lamps are important to see and be
seen on the road.
.Signs that the headlamps need attention
include dimming, failure to light, cracking,
or damage. The brake lamps need to be
checked periodically to ensure that they
light when braking.
.With a multi-point inspection, your dealer
can check the lamps and note any
concerns.
Shocks and Struts
Shocks and struts help aid in control for a
smoother ride.
.Signs of wear may include steering wheel
vibration, bounce/sway while braking,
longer stopping distance, or uneven
tire wear.
.As part of the multi-point inspection,
trained dealer technicians can visually
inspect the shocks and struts for signs of
leaking, blown seals, or damage, and can
advise when service is needed.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
368 Index
IndexA
Accessories and Modifications . . . . . . . . . . . 254
Accessory Power . . . . . . . . . . . . . . . . . . . . . . . . . 205
Active Fuel Management . . . . . . . . . . . . . . . . 206
Adaptive Cruise Control . . . . . . . . . . . . . . . . . . . 217
Add-On Electrical Equipment . . . . . . . . . . . . . 252
Additional InformationOnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361
Additional Maintenance and Care . . . . . . . . 337
Adjustments Lumbar, Front Seats . . . . . . . . . . . . . . . . . . . . 36
Agreements Trademarks and License . . . . . . . . . . . . . . . . 173
Air Cleaner/Filter, Engine . . . . . . . . . . . . . . . . 265
Air Conditioning . . . . . . . . . . . . . . . . . . . . . . . . . .182
Air Filter
Life System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Air Filter, Passenger Compartment . . . . . . . 186
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
How Does an Airbag Restrain? . . . . . . . . . . 54
Passenger Sensing System . . . . . . . . . . . . . . 55
What Makes an Airbag Inflate? . . . . . . . . . 54
What Will You See after an AirbagInflates? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
When Should an Airbag Inflate? . . . . . . . . 53
Where Are the Airbags? . . . . . . . . . . . . . . . . 52 Airbags
Adding Equipment to the Vehicle . . . . . . . 59
Passenger Status Indicator . . . . . . . . . . . . . . 99
Readiness Light . . . . . . . . . . . . . . . . . . . . . . . . . 98
Servicing Airbag-Equipped Vehicles . . . . . . 58
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Alarm
Vehicle Security . . . . . . . . . . . . . . . . . . . . . . . . 23
Alert Lane Change . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Side Blind Zone (SBZA) . . . . . . . . . . . . . . . . . 236
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 288
All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 210, 275
AM-FM Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134
Antenna Multi-band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Antilock Brake System (ABS) . . . . . . . . . . . . . 210 Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . 102
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Apple CarPlay and Android Auto . . . . . . . . . 163
Armrest Storage . . . . . . . . . . . . . . . . . . . . . . . . . . .77
Assistance Program, Roadside . . . . . . . . . . . . 352
Assistance Systems for Driving . . . . . . . . . . 230
Assistance Systems for Parking and Backing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Index 369
AudioBluetooth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Auto Stop Stop/Start System . . . . . . . . . . . . . . . . . . . . . 203
Automatic Dimming Mirrors . . . . . . . . . . . . . . . . . . . . . . . 26
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Emergency Braking (AEB) . . . . . . . . . . . . . . 232
Headlamp System . . . . . . . . . . . . . . . . . . . . . 123
Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
Transmission Fluid . . . . . . . . . . . . . . . . . . . . . 265
Automatic Transmission Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . 209
Shift Lock Control Function Check . . . . . . 275
Avoiding Untrusted Media Devices . . . . . . . . 137
B
Battery Exterior Lighting Battery Saver . . . . . . . . . 127
Load Management . . . . . . . . . . . . . . . . . . . . . 126
Power Protection . . . . . . . . . . . . . . . . . . . . . . . 127
Battery - North America . . . . . . . . . . . . . 274, 318
Blade Replacement, Wiper . . . . . . . . . . . . . . . 276
Bluetooth Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Bluetooth Audio . . . . . . . . . . . . . . . . . . . . . . . . . 140
Brake
Electric Boost . . . . . . . . . . . . . . . . . . . . . . . . . . 210 Brake (cont'd)
Parking, Electric . . . . . . . . . . . . . . . . . . . . . . . . . 211
System Warning Light . . . . . . . . . . . . . . . . . 101
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 Antilock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 Automatic Emergency (AEB) . . . . . . . . . . . 232
Braking System Front Pedestrian (FPB) . . . . . . . . . . . . . . . . . 234
Break-In, New Vehicle . . . . . . . . . . . . . . . . . . . . 200
Bulb Replacement
Back-up Lamps . . . . . . . . . . . . . . . . . . . . . . . . . 278
Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . 278
Headlamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
High Intensity Discharge (HID)Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . . . 302
C
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
California Perchlorate Materials Requirements . . . 254
California Proposition 65 Warning . . . . . . . . . . . . . . . . . . .254, 274, 318,
Back Cover
Canadian Vehicle Owners . . . . . . . . . . . . . . . . . . . 1 Capacities and Specifications . . . . . . . . . . . . . 345
Carbon Monoxide
Engine Exhaust . . . . . . . . . . . . . . . . . . . . . . . . 207
Liftgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . . 195
Cargo Management System . . . . . . . . . . . . . . . . . . . 79
Tie-Downs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Caution, Danger, and Warning . . . . . . . . . . . . . .2
Center Console Storage . . . . . . . . . . . . . . . . . . . .77
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Charging System Light . . . . . . . . . . . . . . . . . . . 100
Check Engine Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Child Restraints Infants and Young Children . . . . . . . . . . . . . 61
Lower Anchors and Tethers forChildren . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Securing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72, 73
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Cleaning
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 327