Vehicle Care 10-31
3. With the engine off, turn theignition to ON/RUN, but do
not start the engine. Without
applying the regular brake, try
to move the shift lever out of
P (Park) with normal effort. If the
shift lever moves out of P (Park),
contact your dealer for service.
Ignition Transmission
Lock Check
While parked, and with the parking
brake set, try to turn the ignition to
LOCK/OFF in each shift lever
position.
.For automatic transmission
vehicles, the ignition should turn
to LOCK/OFF only when the
shift lever is in P (Park). The
ignition key should come out
only in LOCK/OFF.
.For manual transmission
vehicles, the ignition key should
come out only in LOCK/OFF.
Contact your dealer if service is
required.
Park Brake and P (Park)
Mechanism Check
{WARNING
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move. Park on a fairly steep hill, with the
vehicle facing downhill. Keeping
your foot on the regular brake, set
the parking brake.
.To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.
.To check the P (Park)
mechanism's holding ability:
With the engine running, shift
to P (Park). Then release the
parking brake followed by the
regular brake.
Contact your dealer if service is
required.
Vehicle Care 10-41
FuseUsage
1 Heated Seats
2 Grille Guard
3 Stop Lamp
(H3T Only)
4 Roof Rack Lamps
5 Battery Ignition
Switch
6 Front Wiper
7 Regulated Voltage
Control Power
8 Power Locks
9 Sunroof, Front
Washer Pump
10 Accessories (SPO) 11 Not Used
12 Transfer Case
Control Module
13 Radio
14 Body Control
Module Fuse
Usage
15 Rear Wiper Motor
(H3 Only)
16 Rear Wiper Pump
Switch (H3 Only)
17 Air Injection Reactor
(AIR) Pump Relay/
Transmission
Control Module
(TCM) (V8 Only)
18 Rear Vision Camera
19 Cluster
20 Rear Turn Lamp,
Hazard Lamp
21 Powertrain Control
Module 1
22 Mass Air Flow
Sensor, Canister
Vent Purge Solenoid
23 Injector/V8 Coil
24 Fog Lamp
25 Powertrain Control
Module B Fuse
Usage
26 Transmission
Control
Module (TCM)
27 Airbags
28 Not Used
29 Antilock Brake
System, StabiliTrak
®
30Rear Window
Defogger
31 Canister Vent
32 Regulated Voltage
Control Sensor
33 Ignition 1
34 Transmission
35 Cruise Control,
Miscellaneous
36 Horn
37 Driver Side Rear
Park Lamp
38 Amplifier
10-42 Vehicle Care
FuseUsage
39 Daytime Running
Lamps
40 Passenger Side
Headlamp
41 Driver Side
Headlamp
42 Trailer
Back-Up Lamp
43 Front Park Lamps
44 Air Injection Reactor
(AIR) Solenoid
45 Auxiliary Power 2/
Cigarette Lighter
46 Electronic Throttle
Control
47 Oxygen Sensor
48 Air Conditioning
Clutch
49 Rear Park Lamp
50 Stop Lamp Fuse
Usage
51 Auxiliary Power 1/
Cigarette Lighter
52 StabiliTrak
®,
Antilock Brake
System
53 Power Heated Seat,
Belt Switch
54 Fuel System Control
Module (FSCM)
55 Trailer Parking
Lamps
56 Front Turn Signal,
Hazard Signal,
Courtesy Mirror
57 Power Sunroof
58 Transfer Case
Control Module
Switch
59 Climate Controls
Control Head
60 Back‐Up Lamp
61 Power Seats Fuse Usage
62 Air Injection Reactor
(AIR) Pump
63 Passenger Side
Power Window
64 Antilock Brake
System,
StabiliTrak
®2
Solenoid
67 Antilock Brake
System,
StabiliTrak
®1 Motor
68 Driver Side Power
Window
82 Climate Control Fan
83 Electronic Brake
Controller
84 Trailer B+ Fuse
85 Starter
91 Generator Megafuse
10-48 Vehicle Care
(E) Rim Diameter:Diameter of
the wheel in inches.
(F) Load Range
:Load Range.
(G) Service Description
:The
service description indicates the
load index and speed rating of a
tire. If two numbers are given as
in the example, 120/116, then
this represents the load index for
single versus dual wheel usage
(single/dual). 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 psi (pounds per
square inch) or kPa (kilopascal). Accessory Weight
:This
means the combined weight
of optional accessories.
Some examples of optional
accessories are, automatic
transmission, power steering,
power brakes, power windows,
power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.
Belt
:A rubber coated layer of
cords that is located between
the plies and the tread. Cords
may be made from steel or other
reinforcing materials.
Bead
:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim. Bias Ply Tire
:A pneumatic tire
in which the plies are laid at
alternate angles less than
90 degrees to the centerline of
the tread.
Cold Tire Pressure
:The
amount of air pressure in a tire,
measured in psi (pounds per
square inch) or kPa (kilopascal)
before a tire has built up heat
from driving. See Tire Pressure
on page 10‑51.
Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including
the maximum capacity of fuel,
oil, and coolant, but without
passengers and cargo.
10-56 Vehicle Care
You have one minute to match
the first tire/wheel position, and
five minutes overall, to match all
four tire/wheel positions. If it takes
longer than one minute, to match
the first tire and wheel, or more than
five minutes to match all four tire
and wheel positions, the matching
process stops and you need to
start over.
The TPMS sensor matching
procedure is outlined below:
1. Set the parking brake.
2. Turn the ignition switch toON/RUN with the engine off.
3. Turn the exterior lamp switch from AUTO to OFF four times
within three seconds.
A double horn chirp will
sound and the TPMS low tire
warning light starts flashing.
The double horn chirp and
flashing TPMS warning light
indicates the TPMS matching
process has started. The TPMS warning light should continue
flashing throughout the matching
procedure. The LOW TIRE
message displays on the Driver
Information Center (DIC).
4. Start with the driver side front tire.
5. Remove the valve cap from the valve cap stem. Activate the
TPMS sensor by increasing or
decreasing the tire's air pressure
for 10 seconds, then stop and
listen for a single horn chirp. The
single horn chirp should sound
within 15 seconds, confirming
that the sensor identification
code has been matched to this
tire and wheel position. If you
do not hear the confirming
single horn chirp, turn the
ignition switch to LOCK and start
over beginning with Step 2.
6. Proceed to the passenger side front tire, and repeat the
procedure in Step 5. 7. Proceed to the passenger side
rear tire, and repeat the
procedure in Step 5.
8. Proceed to the driver side rear tire, and repeat the procedure in
Step 5.
9. After hearing the confirming horn chirp for the driver side rear tire,
check to see if the TPMS low tire
warning light and the DIC LOW
TIRE messages have turned off.
If yes, the TPMS sensors have
been relearned. Turn the ignition
switch to LOCK/OFF.
If the low tire warning light and
the SERV TPM message on the
DIC are on after completing
Step 5 for the driver side rear
tire, the sensor relearn process
has not been successful. Turn
the ignition switch to LOCK/OFF
and repeat the matching process
beginning with Step 2.
Vehicle Care 10-59
The rubber in tires degrades over
time. This is also true for the spare
tire, if the vehicle has one, even
if it is not being used. Multiple
conditions affect how fast this
aging takes place, including
temperatures, loading conditions,
and inflation pressure maintenance.
With proper care and maintenance
tires typically wear out before they
degrade due to age. If you are
unsure about the need to replace
the tires as they get older, consult
the tire manufacturer for more
information.
Buying New Tires
GM has developed and matched
specific tires for your vehicle.
The original equipment tires
installed on your vehicle, when
it was new, were designed tomeet General Motors Tire
Performance Criteria
Specification (TPC spec)
system rating. If you need
replacement tires, GM strongly
recommends that you get tires
with the same TPC Spec rating.
This way, your vehicle will
continue to have tires that are
designed to give the same
performance and vehicle safety,
during normal use, as the
original tires.
GM's exclusive TPC Spec
system considers over a
dozen critical specifications that
impact the overall performance
of your vehicle, including brake
system performance, ride and
handling, traction control, and
tire pressure monitoring
performance. GM's TPC Spec
number is molded onto the tire's
sidewall near the tire size. If the
tires have an all‐season tread
design, the TPC spec number
will be followed by a MS, for
mud and snow. See
Tire
Sidewall Labeling
on page 10‑44
for additional information.
GM recommends replacing tires
in sets of four. This is because
uniform tread depth on all tires
will help keep your vehicle
performing most like it did when
the tires were new. Replacing
less than a full set of tires can
affect the braking and handling
performance of your vehicle.
Vehicle Care 10-61
Additionally, if your vehicle has
electronic systems such as anti‐lock
brakes, rollover airbags, traction
control, and electronic stability
control, the performance of these
systems can be affected.
{WARNING
If you add different sized
wheels, your vehicle may not
provide an acceptable level of
performance and safety if tires not
recommended for those wheels
are selected. You may increase
the chance that you will crash and
suffer serious injury. Only use
Hummer specific wheel and tire
systems developed for your
vehicle, and have them properly
installed by a GM certified
technician.
See Buying New Tires
on
page 10‑59and Accessories and
Modificationson page 10‑3for
additional information.
Uniform Tire Quality
Grading
Quality grades can be found
where applicable on the tire
sidewall between tread shoulder
and maximum section width. For
example:
Treadwear 200 Traction AA
Temperature A
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration
(NHTSA), which grades tires
by treadwear, traction, and
temperature performance. This
applies only to vehicles sold in
the United States. The grades
are molded on the sidewalls
of most passenger car tires.
The Uniform Tire Quality
Grading (UTQG) system
does not apply to deep
tread, winter-type snow tires, space-saver, or temporary use
spare tires, tires with nominal
rim diameters of 10 to 12 inches
(25 to 30 cm), or to some
limited-production tires.
While the tires available on
Hummer light trucks may vary
with respect to these grades,
they must also conform to
federal safety requirements and
additional General Motors Tire
Performance Criteria (TPC)
standards.
All Passenger Car Tires Must
Conform to Federal Safety
Requirements In Addition To
These Grades.
Treadwear
The treadwear grade is a
comparative rating based
on the wear rate of the tire
when tested under controlled
conditions on a specified
government test course.
Vehicle Care 10-63
If the vehicle vibrates when
driving on a smooth road, the tires
and wheels might need to be
rebalanced. See your dealer for
proper diagnosis.
Wheel Replacement
Replace any wheel that is bent,
cracked, or badly rusted or
corroded. If wheel nuts keep coming
loose, the wheel, wheel bolts, and
wheel nuts should be replaced.
If the wheel leaks air, replace it
(except some aluminum wheels,
which can sometimes be repaired).
See your dealer if any of these
conditions exist.
Your dealer will know the kind of
wheel you need.
Each new wheel should have the
same load-carrying capacity,
diameter, width, offset, and be
mounted the same way as the
one it replaces.If you need to replace any of the
wheels, wheel bolts, wheel nuts,
or Tire Pressure Monitor System
(TPMS) sensors, replace them only
with new GM original equipment
parts. This way, you will be sure to
have the right wheel, wheel bolts,
wheel nuts, and TPMS sensors for
the vehicle.
{WARNING
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts on your vehicle can be
dangerous. It could affect the
braking and handling of your
vehicle, make your tires lose air
and make you lose control. You
could have a collision in which
you or others could be injured.
Always use the correct wheel,
wheel bolts, and wheel nuts for
replacement.
Notice:
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.
See If a Tire Goes Flat
on
page 10‑64for more information.
Used Replacement Wheels
{WARNING
Putting a used wheel on the
vehicle is dangerous. You cannot
know how it has been used or
how far it has been driven.
It could fail suddenly and cause a
crash. If you have to replace a
wheel, use a new GM original
equipment wheel.