VEHICLE CARE 265
cluster. SeeEngine Coolant Temperature
Gauge 0112. The vehicle may also
display a message on the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears, get
service help right away. See Roadside
Service 0353.
If the decision is made to lift the
hood, make sure the vehicle is parked
on a level surface. Then check to see if
the engine cooling fan is running.
If the engine is overheating, the fan
should be running. If it is not, do not
continue to run the engine. Have the
vehicle serviced.
Caution
Do not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all coolant
and can damage the system and
vehicle. Have any leaks fixed
right away.
If Steam Is Coming from the
Engine Compartment
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure cap,
even a little, can cause them to
come out at high speed and you
could be burned. Never turn the cap
when the cooling system, including
the pressure cap, is hot. Wait for
the cooling system and pressure
cap to cool.
If No Steam Is Coming from the
Engine Compartment
If an engine overheat warning is
displayed but no steam can be seen or
heard, the problem may not be too
serious. Sometimes the engine can get
a little too hot when the vehicle:
. Climbs a long hill on a hot day.
. Stops after high-speed driving.
. Idles for long periods in traffic. If the overheat warning is displayed
with no sign of steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest
fan speed. Open the windows as
necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral), and let the
engine idle.
If the engine coolant temperature
gauge is no longer in the overheated
area or the engine coolant
temperature warning light no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
distance from the vehicle in front.
If the warning does not come back on,
continue to drive normally and have
the cooling system checked for proper
fill and function.
If the warning continues, pull over,
stop, and park the vehicle right away.
VEHICLE CARE 267
Warning (Continued)
crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Caution
Continuing to drive with worn-out
brake pads could result in costly
brake repair.
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications. See Capacities and
Specifications 0346. Brake pads should be replaced as
complete sets.
Brake Pedal Travel
See your dealer if the brake pedal does
not return to normal height, or if
there is a rapid increase in pedal
travel. This could be a sign that brake
service may be required.
Replacing Brake System Parts
Always replace brake system parts
with new, approved replacement parts.
If this is not done, the brakes may not
work properly. The braking
performance expected can change in
many other ways if the wrong
replacement brake parts are installed
or if parts are improperly installed.
Brake Fluid
The brake master cylinder reservoir is
filled with GM approved DOT 3 brake
fluid as indicated on the reservoir cap.
See
Engine Compartment Overview
0 252 for the location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a level
surface, the brake fluid level should be
between the minimum and maximum
marks on the brake fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down:
. Normal brake lining wear. When
new linings are installed, the fluid
level goes back up.
. A fluid leak in the brake hydraulic
system. Have the brake hydraulic
system fixed. With a leak, the
brakes will not work well.
Always clean the brake fluid reservoir
cap and the area around the cap
before removing it.
Do not top off the brake fluid. Adding
fluid does not correct a leak. If fluid is
added when the linings are worn,
there will be too much fluid when
276 VEHICLE CARE
FusesUsage
F5 DC DC transformer 2
F6 Amplifier 1
F7 Front blower
F8 Starter 3
F9 –
F10 –
F11 –
F12 Front wiper
F13 Starter 2
F14 LED/Automatic headlamp leveling
F15 Rear wiper 1
F16 –
F17 –
F18 Automatic headlamp leveling module
F19 –
F20 –
F21 –
F22 Electronic brake control module Fuses
Usage
F23 Parking/Trailer lamps
F24 Right trailer stoplamp/Turnlamp
F25 Steering column lock
F26 –
F27 Left trailer stoplamp/ Turnlamp
F28 –
F29 –
F30 Washer pump
F31 –
F32 –
F33 Fog lamps
F34 Horn
F35 –
F36 Headlamp high-beam –left
F37 Headlamp high-beam –right
F38 Automatic headlamp leveling motor Fuses
Usage
F39 Transmission control module/Battery 1
F40 Left rear bus electrical center/Ignition
F41 Instrument cluster
F42 Heating, ventilation, and air conditioning
F43 Head-Up display
F44 Electronic brake control module
electric brake booster/
Run/Crank
F45 –
F46 –
F47 –
F48 Rear wiper 2
F49 Interior rearview mirror/Trailer
F50 Fuel system control module
F51 Heated steering wheel
F52 Air conditioning clutch
VEHICLE CARE 277
FusesUsage
F53 –
F54 Coolant pump
F55 –
F56 –
F57 Engine control module/Ignition
F58 Transmission control module/Ignition
F59 Engine control module battery
F60 –
F61 O2 sensor 1/ Aeroshutter
F62 Engine control module–odd
F63 O2 sensor 2
F64 Engine control module–even
F65 Engine control module powertrain 1
F66 Engine control module powertrain 2 Fuses
Usage
F67 Engine control module powertrain 3
F68 –
F69 –
F70 –
F71 –
F72 –
F73 –
F74 –
F75 –
F76 –
F77 –
Relays Usage
K1 Starter 1
K2 Run/Crank
K3 Starter 3
K4 LED/Automatic headlamps
K5 –
K6 Coolant pump Relays
Usage
K7 Engine control module
K8 Air conditioning
K9 –
K10 Starter 2
Instrument Panel Fuse
Block
The instrument panel fuse block is in
the center console between the driver
and passenger seats. To access the
278 VEHICLE CARE
fuses, open the fuse panel door,
or remove the panel from the
passenger side by pulling it out.
To reinstall the door, push the door
back into its original location.
The vehicle may not be equipped with
all of the fuses, relays, and features
shown.
FusesUsage
F1 Body control module 6 Fuses
Usage
F2 Diagnostic link/ Central gateway
module
F3 Electric steering column lock
F4 –
F5 Logistics
F6 Heating, ventilation, and air conditioning
F7 Body control module 3
F8 –
F9 Right front heated seat
F10 Airbag
F11 –
F12 Amplifier 2
F13 Body control module 7
F14 Left front heated seat
F15 Instrument panel switch bank
VEHICLE CARE 279
FusesUsage
F16 Sunroof
F17 Body control module 1
F18 Instrument cluster
F19 –
F20 Rear seat entertainment
F21 Body control module 4
F22 Infotainment/USB data/Aux jack
F23 Body control module 2
F24 USB charger/ Wireless charging
F25 Park aid/electronic transmission range
system
F26 Communications integration module
F27 Video Fuses
Usage
F28 Heating, ventilation, and air conditioning
display
F29 Radio
F30 Steering wheel adjustment controls
F31 Electronic brake control module
electric brake
booster
F32 DC AC inverter
F33 Driver power seat
F34 Passenger power seat
F35 Battery IEC 1 feed
F36 Electric power steering
F37 Rear seat entertainment/USB
charge/Wireless
charging module
F38 Body control module 8
F39 – Circuit
Breakers Usage
F40 –
F41 –
F42 Auxiliary power outlet/Lighter
Rear Compartment Fuse
Block
The rear compartment fuse block is in
the cargo area, on the driver side of
the vehicle behind the lower trim
286 VEHICLE CARE
description. The letter“T”as the
first character in the tire size
means the tire is for temporary
use only.
(7) TPC Spec (Tire Performance
Criteria Specification)
:Original
equipment tires designed to GM's
specific tire performance criteria
have a TPC specification code
molded onto the sidewall. GM's
TPC specifications meet or exceed
all federal safety guidelines.
Tire Designations
Tire Size
The example shows a typical
passenger vehicle tire size.
(1) Passenger (P-Metric) Tire:
The United States version of a
metric tire sizing system. The
letter “P”as the first character in
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire and
Rim Association.
(2) Tire Width
:The three-digit
number indicates the tire section
width in millimeters from sidewall
to sidewall.
(3) Aspect Ratio
:A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size aspect
ratio is 60, as shown in item (3) of
the illustration, it would mean
that the tire's sidewall is
60 percent as high as it is wide.
(4) Construction Code
:A letter
code is used to indicate the type
of ply construction in the tire. The
letter “R”means radial ply
construction; the letter “D”means
diagonal or bias ply construction. (5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Service Description
:These
characters represent the load
index and speed rating of the tire.
The load index represents the load
carrying capacity a tire is certified
to carry. The speed rating is the
maximum speed a tire is certified
to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of air
inside the tire pressing outward
on each square inch of the tire.
Air pressure is expressed in kPa
(kilopascal) or psi (pounds per
square inch).
Accessory Weight
:The combined
weight of optional accessories.
Some examples of optional
accessories are automatic
transmission, power windows,
power seats, and air conditioning.
290 VEHICLE CARE
How to Check
Use a good quality pocket-type
gauge to check tire pressure.
Proper tire inflation cannot be
determined by looking at the tire.
Check the tire inflation pressure
when the tires are cold, meaning
the vehicle has not been driven for
at least three hours or no more
than 1.6 km (1 mi).
Remove the valve cap from the
tire valve stem. Press the tire
gauge firmly onto the valve to get
a pressure measurement. If the
cold tire inflation pressure
matches the recommended
pressure on the Tire and Loading
Information label, no further
adjustment is necessary. If the
inflation pressure is low, add air
until the recommended pressure is
reached. If the inflation pressure
is high, press on the metal stem in
the center of the tire valve to
release air.Recheck the tire pressure with the
tire gauge.
Put the valve caps back on the
valve stems to keep out dirt and
moisture and prevent leaks. Use
only valve caps designed for the
vehicle by GM. TPMS sensors
could be damaged and would not
be covered by the vehicle
warranty.
Tire Pressure for
High-Speed Operation
{Warning
Driving at high speeds, 160 km/h
(100 mph) or higher, puts additional
strain on tires. Sustained
high-speed driving causes excessive
heat buildup and can cause sudden
tire failure. This could cause a
crash, and you or others could be
killed. Some high-speed rated tires
require inflation pressure
adjustment for high-speed
(Continued)
Warning (Continued)
operation. When speed limits and
road conditions allow the vehicle to
be driven at high speeds, make sure
the tires are rated for high-speed
operation, are in excellent
condition, and are set to the correct
cold tire inflation pressure for the
vehicle load.
Vehicles with 235/65R18 or 235/55R20
size tires require inflation pressure
adjustment when driving the vehicle
at speeds of 160 km/h (100 mph) or
higher. Set the cold inflation pressure
to the maximum inflation pressure
shown on the tire sidewall, or 280 kPa
(41 psi), whichever is lower. Return
the tires to the recommended cold tire
inflation pressure when high-speed
driving has ended. See Vehicle Load
Limits 0170 and
Tire Pressure 0289.
The maximum load and inflation
pressure is molded on the tire
sidewall, in small letters, near the rim