
Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13557845) - 2020 - CRC - 3/24/20
152 Lighting
door is opened after the ignition is
turned off. The dome lamp comes
on after the ignition is turned off.
The exterior lamps and dome lamp
remain on for a set amount of time,
then automatically turn off.
The exterior lamps turn off
immediately by turning the exterior
lamp control off.
This feature can be changed. See
Vehicle Personalization0137.
Battery Load
Management
The vehicle has Electric Power
Management (EPM) that estimates
the battery's temperature and state
of charge. It then adjusts the voltage
for best performance and extended
life of the battery.
When the battery's state of charge
is low, the voltage is raised slightly
to quickly bring the charge back up.
When the state of charge is high,
the voltage is lowered slightly to
prevent overcharging. If the vehicle
has a voltmeter gauge or a voltage
display on the Driver Information Center (DIC), you may see the
voltage move up or down. This is
normal. If there is a problem, an
alert will be displayed.
The battery can be discharged at
idle if the electrical loads are very
high. This is true for all vehicles.
This is because the generator
(alternator) may not be spinning fast
enough at idle to produce all of the
power needed for very high
electrical loads.
A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, rear
window defogger, climate control fan
at high speed, heated seats, engine
cooling fans, trailer loads, and loads
plugged into accessory power
outlets.
EPM works to prevent excessive
discharge of the battery. It does this
by balancing the generator's output
and the vehicle's electrical needs.
It can increase engine idle speed to
generate more power whenever
needed. It can temporarily reduce
the power demands of some
accessories.Normally, these actions occur in
steps or levels, without being
noticeable. In rare cases at the
highest levels of corrective action,
this action may be noticeable to the
driver. If so, a DIC battery voltage
and charging message displays. It is
recommended that the driver reduce
the electrical loads as much as
possible. See
Driver Information
Center (DIC) (Base and Midlevel)
0 129 or
Driver Information Center (DIC)
(Uplevel) 0133.Battery Power Protection
This feature helps prevent the
battery from being drained, if the
interior courtesy lamps or reading
lamps are accidentally left on. If any
of these lamps are left on, they
automatically turn off after
10 minutes, if the ignition is off. The
lamps will not come back on again
until one of the following occurs:
.
The ignition is turned on.
. The doors are closed and then
re-opened.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13557845) - 2020 - CRC - 3/24/20
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-
13557845) - 2020 - CRC - 3/24/20
Vehicle Care 305
{Warning
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts can be dangerous. It could
affect the braking and handling of
the vehicle. Tires can lose air,
and cause loss of control, causing
a crash. Always use the correct
wheel, wheel bolts, and wheel
nuts for replacement.
Caution
The wrong wheel can also cause
problems with bearing life, brake
cooling, speedometer or
odometer calibration, headlamp
aim, bumper height, vehicle
ground clearance, and tire or tire
chain clearance to the body and
chassis.
Used Replacement Wheels
{Warning
Replacing a wheel with a used
one is dangerous. How it has
been used or how far it has been
driven may be unknown. It could
fail suddenly and cause a crash.
When replacing wheels, use a
new GM original equipment
wheel.
Tire Chains
{Warning
If the vehicle has a tire size other
than 235/65R18, do not use tire
chains. There is not enough
clearance. Tire chains used on a
vehicle without the proper amount
of clearance can cause damage
to the brakes, suspension,
or other vehicle parts. The area
damaged by the tire chains could(Continued)
Warning (Continued)
cause loss of control and a crash.
Use another type of traction
device only if its manufacturer
recommends it for the vehicle's
tire size combination and road
conditions. Follow that
manufacturer's instructions. To
avoid vehicle damage, drive slow
and readjust or remove the
traction device if it contacts the
vehicle. Do not spin the wheels. If
traction devices are used, install
them on the front tires.
Caution
If the vehicle is equipped with
235/65R18 size tires, use tire
chains only where legal and only
when necessary. Use low profile
chains that add no more than
12 mm thickness to the tire tread
and inner sidewall. Use chains
(Continued)