Page 273 of 436

Dolly Towing
Two-Wheel-Drive Vehicles
Two-wheel-drive vehicles should not be towed with the
rear wheels on the ground. Two-wheel-drive
transmissions have no provisions for internal lubrication
while being towed. To properly tow these vehicles,
they should be placed on a platform trailer with all four
wheels off the ground.
Four-Wheel-Drive Vehicles
Use the following procedure to tow your vehicle:
1. Firmly set the parking brake.
2. Shift an automatic transmission to PARK (P), or a
manual transmission to FIRST (1).
3. Securely attach the vehicle being towed to the tow
vehicle.
4. Shift the transfer case to NEUTRAL. See
Four-Wheel Drive on page 2-24
5. Release the parking brake only after the vehicle
being towed is ®rmly attached to the towing
vehicle.
6. Turn the ignition to LOCK.
{CAUTION:
Shifting a four-wheel-drive vehicle's transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in Park (P) for
an automatic transmission, or if your vehicle is
in gear, for a manual transmission. You or
others could be injured. Make sure the parking
brake is ®rmly set before you shift the transfer
case to NEUTRAL.
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Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or a lower gear, under heavy
loads or hilly conditions.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine off. If you do get
the overheat warning, see
Engine Overheating on
page 5-27.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here's
how to do it:
1. Apply your regular brakes, but don't shift into
PARK (P) yet. When parking uphill, turn your wheels
away from the curb. When parking downhill, turn
your wheels into the curb.
2. Have someone place chocks behind the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake, and then shift into PARK (P).
5. Release the regular brakes.
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{CAUTION:
It can be dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P) with
the parking brake ®rmly set. Your vehicle
can roll.
If you have left the engine running, the vehicle
can move suddenly. You or others could be
injured. To be sure your vehicle won't move,
even when you're on fairly level ground, use
the steps that follow.
Always put the shift lever fully in PARK (P)
with the parking brake ®rmly set.
If the transfer case on four-wheel drive
vehicles is in NEUTRAL, your vehicle will be
free to roll, even if your shift lever is in
PARK (P). So, be sure the transfer case is in a
drive gear Ð not in NEUTRAL.
See ªFour-Wheel Drive (Automatic Transfer
Case)º in the Index.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
·start your engine,
·shift into a gear, and
·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
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission ¯uid (don't over®ll),
engine oil, axle lubricant, belt(s), cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you ®nd them quickly. If
you're trailering, it's a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
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A cold ¯uid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine
run at idle for ®ve minutes if outside temperatures are
50ÉF (10ÉC) or more. If it's colder than 50ÉF (10ÉC), you
may have to idle the engine longer. Should the ¯uid
level be low during this cold check, you
mustcheck the
¯uid hot before adding ¯uid. Checking the ¯uid hot
will give you a more accurate reading of the ¯uid level.
Checking the Fluid Level
Prepare your vehicle as follows:
·Park your vehicle on a level place. Keep the engine
running.
·With the parking brake applied, place the shift lever
in PARK (P).
·With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK (P).
·Let the engine run at idle for three minutes or more.Then, without shutting off the engine, follow these steps:
The automatic
transmission dipstick
handle with the
transmission and lock
symbol is located in the
engine compartment
on the passenger's side of
the vehicle.
See
Engine Compartment Overview on page 5-12for
more information on location.
1. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again. Check both sides of the
dipstick, and read the lower level.
3. If the ¯uid level is in the acceptable range, push the
dipstick back in all the way; then ¯ip the handle
down to lock the dipstick in place.
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Page 328 of 436

Jump Starting
If your battery has run down, you may want to use
another vehicle and some jumper cables to start your
vehicle. But please use the following steps to do it
safely.
{CAUTION:
Batteries can hurt you. They can be dangerous
because:
·They contain acid that can burn you.
·They contain gas that can explode
or ignite.
·They contain enough electricity to
burn you.
If you do not follow these steps exactly, some
or all of these things can hurt you.
Notice:Ignoring these steps could result in costly
damage to your vehicle that wouldn't be covered
by your warranty.
Trying to start your vehicle by pushing or pulling it
won't work, and it could damage your vehicle.
1. Check the other vehicle. It must have a
12-volt battery with a negative ground system.
Notice:If the other vehicle's system is not a 12-volt
system with a negative ground, both vehicles can
be damaged. Only use vehicles with 12-volt systems
with negative grounds to jump start your vehicle.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake ®rmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake. If
you have a four-wheel-drive vehicle, be sure
the transfer case is not in NEUTRAL.
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Changing a Flat Tire
If a tire goes ¯at, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your
hazard warning ¯ashers.
{CAUTION:
Changing a tire can cause an injury. The
vehicle can slip off the jack and roll over you
or other people. You and they could be badly
injured. Find a level place to change your tire.
To help prevent the vehicle from moving:
1. Set the parking brake ®rmly.
2. Put the shift lever in PARK (P).
3. If you have a four-wheel-drive vehicle,
be sure the transfer case is in a drive
gear ± not in NEUTRAL.
4. Turn off the engine.
5. Put the wheel blocks at the front and rear
of the tire farthest away from the one
being changed. That would be the tire on
the other side of the vehicle, at the
opposite end.The following steps will tell you how to use the jack and
change a tire.
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Page 383 of 436
Fuses Usage
24 Unlock
25 Blank
26 Blank
27 OH Battery/OnStar
žSystem
29 RainsenseŸ Wipers
30 Parking Lamps
31Truck Body Controller 4 Cruise
Control
32 Truck Body Controller 5
33 Front Wipers
34 Vehicle Stop
35 Blank
36Heat Ventilation Air
Conditioning B
37 Front Parking Lamps
38 Left Turn Signal
Fuses Usage
39Heat Ventilation Air
Conditioning 1
40 Truck Body Controller 4
41 Radio
42 Trailer Park
43 Right Turn Signal
44 Heat Ventilation Air Conditioning
45 Rear Fog Lamps
46 Auxiliary Power 1
47 Ignition 0
48 Four-Wheel Drive
49 Blank
50 Truck Body Controller Ignition
51 Brakes
52 Truck Body Controller Run
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Fuses Usage
22 Retained Accessory Power
23 Blank
24 Unlock
25 Blank
26 Blank
27 OH Battery/OnStar
žSystem
28 Sunroof
29 RainsenseŸ Wipers
30 Parking Lamps
31Truck Body Controller 4
Cruise Control
32 Truck Body Controller 5
33 Front Wipers
34 Vehicle Stop
35 Blank
36Heat Ventilation Air
Conditioning B
Fuses Usage
37 Front Parking Lamps
38 Left Turn Signal
39Heat Ventilation Air
Conditioning 1
40 Truck Body Controller 4
41 Radio
42 Trailer Park
43 Right Turn Signal
44 Heat Ventilation Air Conditioning
45 Rear Fog Lamps
46 Auxiliary Power 1
47 Ignition 0
48 Four-Wheel Drive
49 Blank
50 Truck Body Controller Ignition
51 Brakes
52 Truck Body Controller Run
5-99