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{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO (carbon
monoxide) gas to get inside. CO could
overcome you and kill you. You cannot see it
or smell it, so you might not know it is in your
vehicle. Clear away snow from around the
base of your vehicle, especially any that is
blocking your exhaust pipe. And check around
again from time to time to be sure snow does
not collect there.
Open a window just a little on the side of the
vehicle that is away from the wind. This will
help keep CO out.Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little
faster than just idle. That is, push the accelerator
slightly. This uses less fuel for the heat that you get and
it keeps the battery charged. You will need a
well-charged battery to restart the vehicle, and possibly
for signaling later on with your headlamps. Let the
heater run for a while.
Then, shut the engine off and close the window almost
all the way to preserve the heat. Start the engine
again and repeat this only when you feel really
uncomfortable from the cold. But do it as little as
possible. Preserve the fuel as long as you can. To help
keep warm, you can get out of the vehicle and do
some fairly vigorous exercises every half hour or so until
help comes.
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Heavy-DutyTrailer Wiring Harness
Package
For vehicles equipped with heavy duty trailering, the
harness is connected to the trailer plug mounted to the
hitch platform.The eight-wire harness contains the following trailer
circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
Light Blue: CHMSL*
Red: Battery Feed**
Dark Blue: Trailer Brake
* The Center High-Mounted Stoplamp (CHMSL) wire is
tied next to the trailer wiring harness for use with a
trailer, slide-in camper or cap.
**If your vehicle is charging a remote (non-vehicle)
battery, turn on the headlamps to boost the vehicle
system voltage and properly charge the battery.
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Service............................................................5-4
Doing Your Own Service Work.........................5-5
Adding Equipment to the Outside
of Your Vehicle...........................................5-6
Fuel................................................................5-6
Gasoline Octane............................................5-6
Gasoline Speci cations....................................5-7
California Fuel...............................................5-7
Additives.......................................................5-7
Fuel E-85 (85% Ethanol).................................5-8
Fuels in Foreign Countries...............................5-9
Filling Your Tank..........................................5-10
Filling a Portable Fuel Container.....................5-12
Checking Things Under the Hood....................5-12
Hood Release..............................................5-13
Engine Compartment Overview.......................5-14
Engine Oil (Gasoline Engine)..........................5-20
Engine Oil Life System (Gasoline Engine)........5-23
Engine Air Cleaner/Filter................................5-25
Automatic Transmission Fluid
(Except Allison Transmission
®) ....................5-27
Automatic Transmission Fluid
(Allison Transmission
®) ...............................5-30
Manual Transmission Fluid.............................5-33
Hydraulic Clutch...........................................5-34Engine Coolant.............................................5-35
Coolant Surge Tank Pressure Cap..................5-37
Engine Overheating.......................................5-37
Overheated Engine Protection Operating
Mode (V8 Engines Only)............................5-39
Cooling System............................................5-40
Engine Fan Noise.........................................5-45
Power Steering Fluid.....................................5-46
Windshield Washer Fluid................................5-48
Brakes........................................................5-49
Battery........................................................5-52
Jump Starting...............................................5-53
Rear Axle.......................................................5-58
Four-Wheel Drive............................................5-58
Front Axle......................................................5-60
Noise Control System.....................................5-61
Tampering with Noise Control System
Prohibited.................................................5-61
Bulb Replacement..........................................5-62
Halogen Bulbs..............................................5-62
Headlamps..................................................5-63
Front Turn Signal, Sidemarker and
Daytime Running Lamps.............................5-64
Roof Marker Lamps......................................5-65
Section 5 Service and Appearance Care
5-1
Page 457 of 574
Headlamps
To replace a headlamp bulb, do the following:
1. If your vehicle is equipped with two pins, remove
the two pins on the top of the headlamp assembly.
To remove the pins, turn the outer pin outward
and pull it straight up. To remove the inner pin, turn
it in and pull it straight up.If your vehicle has one pin on the headlamp
assembly, remove the pin. To remove the pin, turn
the pin up and pull it out straight out.
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A. Low-Beam Headlamp
B. High-Beam Headlamp
2. Pull the headlamp assembly out.
3. Unplug the electrical connector.
4. Turn the old bulb counterclockwise and remove it
from the headlamp assembly.
5. Put the new bulb into the assembly and turn it
clockwise until it is tight. Use care not to touch
the bulb with your ngers or hands.
6. Plug in the electrical connector.
7. Put the headlamp assembly back into the vehicle.
8. Install and tighten the two pins. If your vehicle
has one pin, install it and turn it into the locking
feature.
Front Turn Signal, Sidemarker and
Daytime Running Lamps
A. Sidemarker Lamp
B. Retainer Clip
C. Front Turn Signal Lamp
D. Daytime Running Lamp (DRL)
To replace a front turn signal, sidemarker or DRL bulb,
do the following:
1. Remove the headlamp assembly as described
previously. SeeHeadlamps on page 5-63for
more information.
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2. Press the retainer clip (B), located behind the turn
signal housing, towards the outside of the vehicle.
3. Pull the turn signal housing out of the vehicle.
4. Press the locking release lever, turn the bulb socket
counterclockwise and remove it from the turn signal
housing.
5. Remove the old bulb from the bulb socket.
6. Put a new bulb into the bulb socket. Use care not
to touch the bulb with your ngers or hands.7. Put the bulb socket back into the turn signal
housing and turn it clockwise until it locks.
8. Put the turn signal housing back into the vehicle
placing the hook and posts on the inner side into
the alignment holes rst, then the outer side into the
retainer bracket until you hear a click.
9. Put the headlamp assembly back into the vehicle.
Roof Marker Lamps
To replace a roof marker lamp bulb, do the following:
1. Remove the two
screws and lift
off the lens.
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Taillamps (Chassis Cab Models)
A. Turn Signal Lamp
B. Stoplamp
C. Back-up Lamp
To replace a taillamp bulb for chassis cab models, do
the following:
1. Peel the rubber seal away from the lens using
your hands.
2. Lift the lens off the lamp assembly.
3. Pull the old bulb straight out from the socket.
4. Put a new bulb into the socket and press it in until it
is tight.
5. Reinstall the lens and the lens seal.
Replacement Bulbs
Exterior Lamp Bulb Number
Back-up Lamp 3157
Back-up Lamp* 1156
Cargo Lamp 912
Center High-Mounted Stoplamp
(CHMSL)912
Daytime Running Lamps (DRL) 4114K
Fender Marker Lamps 194
Front Parking and Turn Lamp 3457A
Front Roof Marker Lamps 194
Headlamps
High-Beam 9005
Low-Beam 9006
Rear Marker Lamp, Taillamp and
Stoplamp*3157
Rear Turn Signal Lamp 3157
Rear Turn Signal Lamp* 1156
Sidemarker Lamp (If Equipped) 194
Stoplamp and Taillamp* 1157
* Chassis Cab Models
For replacement bulbs not listed here, contact
your dealer.
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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 your wheels, wheel bolts
or wheel nuts, replace them only with new GM
original equipment parts. This way, you will be sure to
have the right wheel, wheel bolts and wheel nuts
for your vehicle.
{CAUTION:
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.
Whenever a wheel, wheel bolt or wheel nut is replaced
on a dual wheel setup, check the wheel nut torque
after 100, 1,000 and 6,000 miles (160, 1 600 and
10 000 km) of driving. For proper torque, see “Wheel Nut
Torque” underCapacities and Speci cations on
page 5-130.
SeeChanging a Flat Tire on page 5-92for more
information.Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can’t know how it’s been used
or how far it’s been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
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