Engine oil GMC YUKON 2001 User Guide

4-52
Your vehicle is equipped with a button at the end of the shift
lever which, when pressed, enables tow/haul. Your vehicle
may be equipped with Autoride
 which further improves
your vehicle's ride while towing. See ªAutorideº in the
Index for more information. When the button is pressed, a
light on the instrument panel will illuminate to indicate that
tow/haul has been selected. Tow/haul may be turned off by
pressing the button again, at which time the indicator light
on the instrument panel will turn off. The vehicle will
automatically turn off tow/haul every time it is started.
Tow/haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75% of
the vehicle's Gross Combined Weight Rating (GCWR).
Tow/haul is most useful under the following
driving conditions:

When pulling a heavy trailer or a large or heavy load
through rolling terrain.

When pulling a heavy trailer or a large or heavy load
in stop and go traffic.

When pulling a heavy trailer or a large or heavy load
in busy parking lots where improved low speed
control of the vehicle is desired.
Operating the vehicle in tow/haul when lightly loaded or
with no trailer at all will not cause damage. However,
there is no benefit to the selection of tow/haul when the vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission driving
characteristics and reduced fuel economy. Tow/haul is
recommended only when pulling a heavy trailer or a large
or heavy load. Your vehicle may be equipped with
Autoride
. If it is, see ªAutorideº in the Index.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For example,
speed, altitude, road grades, outside temperature and
how much your vehicle is used to pull a trailer are all
important. And, it can also depend on any special
equipment that you have on your vehicle.
Use one of the following charts to determine how much
your vehicle can weigh, based upon your vehicle model
and options.
Maximum trailer weight is calculated assuming only the
driver is in the tow vehicle and it has all the required
trailering equipment. The weight of additional optional
equipment, passengers and cargo in the tow vehicle
must be subtracted from the maximum trailer weight.
The engine oil cooler and the heavy
-duty trailering
package is required on C/K
-2500 models with the
VORTEC 6000 engine.

4-59 Making Turns
NOTICE:
Making very sharp turns while trailering could
cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you're turning with a trailer, make wider turns than
normal. Do this so your trailer won't strike soft shoulders,
curbs, road signs, trees or other objects. Avoid jerky or
sudden maneuvers. Signal well in advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will flash
whenever you signal a turn or lane change. Properly
hooked up, the trailer lamps will also flash, telling other
drivers you're about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will flash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind you
are seeing your signal when they are not. It's important
to check occasionally to be sure the trailer bulbs are
still working.
Driving On Grades
Reduce speed and shift to a lower gear before you
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, if necessary, a lower gear
selection if the transmission shifts too often (e.g., under
heavy loads and/or hilly conditions).
You may also want to activate the tow/haul mode if the
transmission shifts too often. See ªTow/Haul Modeº
in the Index.
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 ªEngine Overheatingº
in the Index.

4-61 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 fluid (don't overfill),
engine oil, axle lubricant, belts, belt, cooling system and
brake system. Each of these is covered in this manual, and
the Index will help you find 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.

5-8
3. Disconnect the red positive (+) cable from the
vehicle with the good battery.
4. Disconnect the red positive (+) cable from the
other vehicle.
Towing Your Vehicle
Consult your dealer or a professional towing service if
you need to have your vehicle towed. See ªRoadside
Assistanceº and ªRecreational Vehicle Towingº in
the Index.
Engine Overheating
You will find a coolant temperature gage on your
vehicle's instrument panel. See ªEngine Coolant
Temperature Gageº in the Index. In addition, you
will find a LOW COOLANT, CHECK COOLANT
TEMP, ENGINE OVERHEATED and a REDUCED
ENGINE POWER message in the message center
on the instrument panel. See ªMessage Centerº
in the Index.
Overheated Engine Protection Operating
Mode (V8 Engines Only)
Should an overheated engine condition exist and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates firing groups
of cylinders helps prevent engine damage. In this mode,
you will notice a loss in power and engine performance.
This operating mode allows your vehicle to be driven to
a safe place in an emergency. Towing a trailer in the
overheat protection mode should be avoided.
NOTICE:
After driving in the overheated engine protection
operating mode, to avoid engine damage, allow the
engine to cool before attempting any repair. The
engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the
oil life monitor. See ªEngine Oilº in the Index.

5-12
If the coolant inside the coolant surge tank is boiling,
don't do anything else until it cools down.
When the engine is
cold, the coolant level
should be at or above
the FILL COLD mark.
If it isn't, you may
have a leak in the
radiator hoses, heater
hoses, radiator, water
pump or somewhere
else in the
cooling system.
CAUTION:
Heater and radiator hoses, and other engine parts,
can be very hot. Don't touch them. If you do, you
can be burned.
Don't run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
NOTICE:
Engine damage from running your engine
without coolant isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index.
NOTICE:
When adding coolant, it is important that you use
only DEX
-COOL
(silicate-free) coolant.
If coolant other than DEX-COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by
the use of coolant other than DEX
-COOL
is
not covered by your new vehicle warranty.
If there seems to be no leak, start the engine again. See if
the engine cooling fan speed increases when idle speed is
doubled by pushing the accelerator pedal down. If it
doesn't, your vehicle needs service. Turn off the engine.

5-14
CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant mixture will. Your vehicle's coolant
warning system is set for the proper coolant
mixture. With plain water or the wrong mixture,
your engine could get too hot but you wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.
NOTICE:
In cold weather, water can freeze and crack the
engine, radiator, heater core and other parts.
So use the recommended coolant.
CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot
enough. Don't spill coolant on a hot engine.

6-
6-1
Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
-2 Service
6
-3 Fuel
6
-5 Fuels in Foreign Countries
6
-5 Filling Your Tank
6
-8 Filling a Portable Fuel Container
6
-8 Checking Things Under the Hood
6
-13 Noise Control System
6
-14 Engine Oil
6
-18 Engine Air Cleaner/Filter
6
-20 Passenger Compartment Air Filter
(If Equipped)
6
-21 Automatic Transmission Fluid
6
-25 Rear Axle
6
-25 Four-Wheel Drive
6
-27 Engine Coolant
6
-30 Coolant Surge Tank Pressure Cap
6
-30 Power Steering Fluid6
-32 Windshield Washer Fluid
6
-33 Brakes
6
-37 Battery
6
-37 Bulb Replacement
6
-43 Windshield Wiper Blade Replacement
6
-44 Tires
6
-53 Appearance Care
6
-53 Cleaning the Inside of Your Vehicle
6
-57 Cleaning the Outside of Your Vehicle
6
-61 GM Vehicle Care/Appearance Materials
6
-62 Vehicle Identification Number (VIN)
6
-63 Electrical System
6
-71 Replacement Bulbs
6
-72 Capacities and Specifications
6
-74 Normal Maintenance Replacement Parts

6-5
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent deposits from forming in your engine and fuel
system, allowing your emission control system to
function properly. Therefore, you should not have
to add anything to the fuel. In addition, gasolines
containing oxygenates, such as ethers and ethanol, and
reformulated gasolines may be available in your area to
contribute to clean air. General Motors recommends that
you use these gasolines, particularly if they comply with
the specifications described earlier.
NOTICE:
Your vehicle was not designed for fuel that
contains methanol. Don't use it. It can corrode
metal parts in your fuel system and also damage
plastic and rubber parts. That damage wouldn't
be covered under your warranty.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard to
find. Never use leaded gasoline or any other fuel not
recommended in the previous text on fuel. Costly repairs
caused by use of improper fuel wouldn't be covered by
your warranty.
To check on fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you'll be driving.
Filling Your Tank
CAUTION:
Gasoline vapor is highly flammable. It burns
violently, and that can cause very bad injuries.
Don't smoke if you're near gasoline or refueling
your vehicle. Keep sparks, flames and smoking
materials away from gasoline.

6-8
Filling a Portable Fuel Container
CAUTION:
Never fill a portable fuel container while it is in
your vehicle. Static electricity discharge from the
container can ignite the gasoline vapor. You can
be badly burned and your vehicle damaged if this
occurs. To help avoid injury to you and others:

Dispense gasoline only into
approved containers.

Do not fill a container while it is inside a
vehicle, in a vehicle's trunk, pickup bed
or on any surface other than the ground.

Bring the fill nozzle in contact with the
inside of the fill opening before operating
the nozzle. Contact should be maintained
until the filling is complete.

Don't smoke while pumping gasoline.
Checking Things Under the Hood
CAUTION:
Things that burn can get on hot engine parts and
start a fire. These include liquids like fuel, oil,
coolant, brake fluid, windshield washer and other
fluids, and plastic or rubber. You or others could
be burned. Be careful not to drop or spill things
that will burn onto a hot engine.

6-11
A. Engine Air Cleaner/Filter
B. Coolant Surge Tank
C. Air Filter Restriction Indicator
D. Engine Oil Dipstick
E. Automatic Transmission Dipstick (If Equipped)
F. Engine Oil Fill
G. FanH. Remote Negative (-) Terminal (GND)
I. Power Steering Fluid Reservoir
J. Remote Positive (+) Terminal
K. Brake Fluid Reservoir
L. Underhood Electrical Center
M. Battery
N. Windshield Washer Fluid Reservoir