brake CHEVROLET BLAZER 2020 Repair Manual

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13557845) - 2020 - CRC - 3/24/20
Driving and Operating 231
Warning (Continued)
.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 0186.
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 0237. 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
alone. It is necessary to go much
farther beyond the passed vehicle
before returning to the lane. Pass
on level roadways. Avoid passing
on hills if possible.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand to
the left. To move the trailer to the
right, move that hand to the right.
Always back up slowly and,
if possible, have someone
guide you.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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232 Driving and Operating
Making TurnsCaution
Turn more slowly and make wider
arcs when towing a trailer to
prevent damage to your vehicle.
Making very sharp turns could
cause the trailer to contact the
vehicle.
Make wider turns than normal when
towing, so the trailer will not go over
soft shoulders, over curbs, or strike
road signs, trees, or other objects.
Always signal turns well in advance.
Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower
gear before starting down a long or
steep downhill grade. If the
transmission is not shifted down, the
brakes may overheat and result in
reduced braking efficiency. The vehicle can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts too
often under heavy loads and/or hilly
conditions.
When towing at higher altitudes,
engine coolant will boil at a lower
temperature than at lower altitudes.
If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle could show signs similar to
engine overheating. To avoid this,
let the engine run, preferably on
level ground, with the transmission
in P (Park) for a few minutes before
turning the engine off. If the
overheat warning comes on, see
Engine Overheating
0264.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and
trailer on a level surface when
possible.
When parking the vehicle and trailer
on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into the curb if
facing downhill or into traffic if
facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, gradually release the
brake pedal to allow the chocks
to absorb the load of the trailer.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Driving and Operating 233
4. Reapply the brake pedal. Thenapply the parking brake and
shift into P (Park).
5. Release the brake pedal.
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
theMaintenance Schedule 0339.
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
0 264.
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

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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234 Driving and Operating
.Maximum Trailer Weight Rating
. Maximum Trailer Tongue Weight
Rating
See “Weight-Distributing Hitch
Adjustment” underTowing
Equipment 0237 to determine if
equalizer bars are required to obtain
the maximum trailer weight rating.
See “Trailer Brakes” underTowing
Equipment 0237 to determine if
brakes are required based on your
trailer's weight. The only way to be sure the weight
is not exceeding any of these
ratings is to weigh the tow vehicle
and trailer combination, fully loaded
for the trip, getting individual
weights for each of these items.
{Warning
You and others could be seriously
injured or killed if the trailer is too
heavy or the trailer brakes are
inadequate for the load. The
vehicle may be damaged, and the
repairs would not be covered by
the vehicle warranty.
Only tow a trailer if all the steps in
this section have been followed.
Ask your dealer for advice and
information about towing a trailer.
Gross Combined Weight
Rating (GCWR)
GCWR is the total allowable weight
of the completely loaded vehicle
and trailer including any fuel,
passengers, cargo, equipment, and
accessories. Do not exceed the
GCWR for your vehicle. The GCWR
for the vehicle is on the tow rating
chart later in this section.
To check that the weight of the
vehicle and trailer are within the
GCWR for the vehicle, follow these
steps:
1. Start with the "curb weight" from the Trailering Information
label.
2. Add the weight of the trailer loaded with cargo and ready
for the trip.
3. Add the weight of all passengers.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Driving and Operating 239
.Tires must be properly inflated to
support loads while towing a
trailer. See Tires0284 for
instructions on proper tire
inflation.
Safety Chains
Always attach chains between the
vehicle and the trailer, and attach
the chains to the holes on the trailer
hitch platform. Instructions for safety
chains may be provided by the hitch
manufacturer or by the trailer
manufacturer.
Cross the safety chains under the
tongue of the trailer to help prevent
the tongue from contacting the road
if it becomes separated from the
hitch. Always leave just enough
slack so the combination can turn.
Never allow safety chains to drag on
the ground.
Trailer Brakes
Loaded trailers over 450 kg
(1,000 lb) must be equipped with
brake systems and with brakes for
each axle. Trailer braking equipment
conforming to Canadian Standards Association (CSA) requirement
CAN3-D313, or its equivalent, is
recommended.
State or local regulations may
require trailers to have their own
braking system if the loaded weight
of the trailer exceeds certain
minimums that can vary from state
to state. Read and follow the
instructions for the trailer brakes so
they are installed, adjusted, and
maintained properly. Never 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 Brakes
The 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.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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240 Driving and Operating
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.
Tow/Haul Mode
For instructions on how to enter
Tow/Haul Mode, see
Driver Mode
Control 0196.
Tow/Haul assists when pulling a
heavy trailer or a large or heavy
load. See Tow/Haul Mode 0190.
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 0233. 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

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Driving and Operating 241
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
Control0194.
{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
(Continued)
Warning (Continued)
cargo, improper trailer hitch
configuration, or improperly
inflated or incorrect vehicle or
trailer tires. SeeTowing
Equipment 0237 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.
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

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 243
Vehicle Care
General Information
General Information . . . . . . . . . . 244
California Proposition65 Warning . . . . . . . . . . . . . . . . . 244
California Perchlorate Materials Requirements . . . . . 245
Accessories and Modifications . . . . . . . . . . . . . . . . 245
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 245
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 246
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 248
Engine Oil . . . . . . . . . . . . . . . . . . . . 253
Engine Oil Life System . . . . . . . 255
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 256
Engine Air Filter Life System . . . . . . . . . . . . . . . . . . . . . . 257
Engine Air Cleaner/Filter . . . . . . 257
Cooling System . . . . . . . . . . . . . . 259
Engine Overheating . . . . . . . . . . 264
Washer Fluid . . . . . . . . . . . . . . . . . 265
Brakes . . . . . . . . . . . . . . . . . . . . . . . 266
Brake Fluid . . . . . . . . . . . . . . . . . . . 267 Battery - North America . . . . . . 268
All-Wheel Drive . . . . . . . . . . . . . . . 269
Starter Switch Check . . . . . . . . . 269
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 269
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 269
Wiper Blade Replacement . . . . 270
Windshield Replacement . . . . . 271
Gas Strut(s) . . . . . . . . . . . . . . . . . . 271
Headlamp Aiming
Front Headlamp Aiming . . . . . . 273
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 273
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 273
LED Lighting . . . . . . . . . . . . . . . . . 273
Back-Up Lamps . . . . . . . . . . . . . . 273
Electrical System
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . . . 274
Electrical System Overload . . . 275
Fuses and Circuit Breakers . . . 275
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 276
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 279 Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 282
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 284
All-Season Tires . . . . . . . . . . . . . . 285
Winter Tires . . . . . . . . . . . . . . . . . . 285
Summer Tires . . . . . . . . . . . . . . . . 286
Tire Sidewall Labeling . . . . . . . . 286
Tire Designations . . . . . . . . . . . . . 288
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 289
Tire Pressure . . . . . . . . . . . . . . . . . 291
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 293
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 293
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 294
Tire Inspection . . . . . . . . . . . . . . . . 298
Tire Rotation . . . . . . . . . . . . . . . . . 299
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . 300
Buying New Tires . . . . . . . . . . . . . 301
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . 302
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . . . 302
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . 304
Wheel Replacement . . . . . . . . . . 304

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 245
California Perchlorate
Materials Requirements
Certain types of automotive
applications, such as airbag
initiators, seat belt pretensioners,
and lithium batteries contained in
electronic keys, may contain
perchlorate materials. Perchlorate
Material–special handling may
apply. See www.dtsc.ca.gov/
hazardouswaste/perchlorate.
Accessories and
Modifications
Adding non-dealer accessories or
making modifications to the vehicle
can affect vehicle performance and
safety, including such things as
airbags, braking, stability, ride and
handling, emissions systems,
aerodynamics, durability, and
electronic systems like antilock
brakes, traction control, and stability
control. These accessories or
modifications could even cause
malfunction or damage not covered
by the vehicle warranty. Damage to suspension components
caused by modifying vehicle height
outside of factory settings will not be
covered by the vehicle warranty.
Damage to vehicle components
resulting from modifications or the
installation or use of non-GM
certified parts, including control
module or software modifications, is
not covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
GM Accessories are designed to
complement and function with other
systems on the vehicle. See your
dealer to accessorize the vehicle
using genuine GM Accessories
installed by a dealer technician.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle 070.
Vehicle Checks
Doing Your Own
Service Work
{Warning
It can be dangerous to work on
your vehicle if you do not have
the proper knowledge, service
manual, tools, or parts. Always
follow owner ’s manual procedures
and consult the service manual
for your vehicle before doing any
service work.
If doing some of your own service
work, use the proper service
manual. It tells you much more
about how to service the vehicle
than this manual can. To order the
proper service manual, see
Publication Ordering Information
0 364.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 249
1.Engine Air Cleaner/Filter 0257.
2. Engine Oil Fill Cap. See Engine Oil 0253.
3. Engine Oil Dipstick. See Engine Oil 0253.
4. Engine Cooling Fan (Out of View). See Cooling System
0 259.
5. Brake Fluid Reservoir. See Brake Fluid 0267. 6.
Battery - North America 0268.
7. Engine Coolant Surge Tank and Pressure Cap. See
Cooling System 0259.
8. Positive (+) Battery Terminal (Under Cover). See Jump
Starting - North America 0321. 9. Windshield Washer Fluid
Reservoir. See Washer Fluid
0 265.
10. Engine Compartment Fuse
Block 0276.
11. Remote Negative (-) Battery Terminal. See Jump Starting -
North America 0321.