2001 GMC YUKON XL DENALI transmission oil

2-71
If the transmission fluid reaches temperatures of
approximately 275
F (135
C) or greater, the message
center will display a TRANS HOT...IDLE ENG warning
message. Pull the vehicle off the roadway when it is safe
to do so. Set the parking brake, place the transmission in
PARK (P) and allow the engine to idle until the
transmission temperature falls below 260
F (127
C).
If the transmission continues to operate above 265
F
(130
C), please contact your nearest dealer or the GM
Roadside Assistance Center.
NOTICE:
If you keep driving your vehicle with the
transmission temperature gage above the normal
operating range, you can damage the
transmission. This could lead to costly repairs
that may not be covered under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:

Towing a trailer

Hot outside air temperatures

Hauling a large or heavy load

Low transmission fluid level

High transmission fluid level

Restricted air flow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures on
a frequent basis, see ªScheduled Maintenanceº in the
Index for the proper transmission maintenance intervals.

2-78 Trans Fluid Hot
Your vehicle has a transmission temperature warning
display contained in the message center.
If the transmission fluid
temperature becomes high,
the message center will
display this message.
When the transmission enters the protection mode,
you may notice a change in the transmission shifting
patterns. When the transmission fluid temperature
returns to normal, the display will turn off and the
transmission shifting patterns will return to normal.
NOTICE:
If you keep driving your vehicle with the
transmission TRANS FLUID HOT message
displayed, you can damage the transmission. This
could lead to costly repairs that may not be
covered under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:

Towing a trailer

Hot outside air temperatures

Hauling a large or heavy load

Low transmission fluid level

High transmission fluid level

Restricted air flow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures on
a frequent basis, see ªScheduled Maintenanceº in the
Index for the proper transmission maintenance intervals.

2-79 Trans Hot...Idle Engine
Your vehicle has a transmission over-temperature
display contained in the message center.
If this warning message is
displayed, pull the vehicle
off the roadway when it is
safe to do so.
Set the parking brake and place the transmission in
PARK (P). Idle the engine until the message center no
longer displays a message. If idling the engine does not
turn the warning message off after 10 to 15 minutes,
contact your nearest dealer or the GM Roadside
Assistance Center. See ªRoadside Assistanceº in
the Index.
NOTICE:
If you keep driving your vehicle with the
transmission TRANS HOT...IDLE ENGINE
message displayed, you can damage the
transmission. This could lead to costly repairs
that may not be covered under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:

Towing a trailer

Hot outside air temperatures

Hauling a heavy load

Low transmission fluid level

High transmission fluid level

Restricted air flow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures on
a frequent basis, see ªScheduled Maintenanceº in the
Index for the proper transmission maintenance intervals.

4-50 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.

4-52 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, 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.
Trailer Wiring Harness
Heavy-Duty Trailer Wiring Package
Your vehicle is equipped with the seven-wire trailer
towing harness. This harness with a seven
-pin universal
heavy
-duty trailer connector is attached to a bracket on
the platform hitch.

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
-7 Filling a Portable Fuel Container
6
-8 Checking Things Under the Hood
6
-10 Engine Oil
6
-15 Engine Air Cleaner/Filter
6
-17 Passenger Compartment Air Filter
6
-17 Automatic Transmission Fluid
6
-21 Rear Axle
6
-21 All-Wheel Drive
6
-24 Engine Coolant
6
-27 Coolant Surge Tank Pressure Cap
6
-28 Power Steering Fluid6
-29 Windshield Washer Fluid
6
-30 Brakes
6
-34 Battery
6
-35 Bulb Replacement
6
-39 Windshield Wiper Blade Replacement
6
-40 Tires
6
-48 Appearance Care
6
-49 Cleaning the Inside of Your Vehicle
6
-52 Cleaning the Outside of Your Vehicle
6
-56 GM Vehicle Care/Appearance Materials
6
-57 Vehicle Identification Number (VIN)
6
-58 Electrical System
6
-66 Replacement Bulbs
6
-66 Capacities and Specifications
6
-67 Normal Maintenance Replacement Parts

6-9 Engine Compartment Overview
When you lift the hood on the VORTEC 6000 engine, you'll see:
A. Engine Air Cleaner/Filter
B. Coolant Surge Tank
C. Air Filter Restriction Indicator
D. Engine Oil Dipstick
E. Engine Oil Fill
F. Automatic Transmission DipstickG. Fan
H. Remote Negative (
-)
Terminal (GND)
I. Remote Positive (+) Terminal
J. Power Steering Fluid ReservoirK. Brake Fluid Reservoir
L. Underhood Electrical Center
M. Battery
N. Windshield Washer
Fluid Reservoir

6-17
Passenger Compartment Air Filter
The filter is located under the instrument panel below
the glove compartment.
To replace the passenger compartment air filter do
the following:
1. Remove the bolts on the access panel and set the
panel aside. Because this operation can be a little
difficult, you may choose to have it done at your
dealer's service department.
2. Reach under the
instrument panel
towards the front of
the vehicle and pull
down on the filter
retaining bracket.
3. Remove the air filter by pulling down on the
element. Remove the second portion of the air filter
by sliding it towards the rear of the vehicle and then
pulling downward.4. Install the new filter by reversing the steps listed
previously. Be sure to follow any instructions that
may be included in the replacement filter package.
Refer to the Maintenance Schedule to determine when
to replace the passenger compartment air filter. See
ªScheduled Maintenanceº in the Index.
Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every 50,000 miles
(83 000 km) if the vehicle is mainly driven under one
or more of these conditions:

In heavy city traffic where the outside temperature
regularly reaches 90F (32C) or higher.

In hilly or mountainous terrain.

When doing frequent trailer towing.

Uses such as found in taxi, police or delivery service.
If you do not use your vehicle under any of
these conditions, change the fluid and filter
every 100,000 miles (166 000 km).
See ªScheduled Maintenance Servicesº in the Index.