towing GMC YUKON DENALI 2002 Owner's Manual

5-9
Towing Your Vehicle
Consult your dealer or a professional towing service
if you need to have your disabled vehicle towed.
See ªRoadside Assistanceº 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
If an overheated engine condition exists 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. Driving extended miles
(km) and/or 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 system. See ªEngine Oilº in the Index.

5-19
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the fan speed
increases as the clutch more fully engages. So you may
hear an increase in fan noise. This is normal and should
not be mistaken as the transmission slipping or making
extra shifts. It is merely the cooling system functioning
properly. The fan will slow down when additional
cooling is not required and the clutch disengages.
You may also hear this fan noise when you start
the engine. It will go away as the fan clutch
partially disengages.
If a Tire Goes Flat
It's unusual for a tire to ªblow outº while you're driving,
especially if you maintain your tires properly. If air goes
out of a tire, it's much more likely to leak out slowly.
But if you should ever have a ªblowout,º here are a few
tips about what to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you'd use in a
skid. In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop
-- well off the road if possible.
If a tire goes flat, the next part shows how to use your
jacking equipment to change a flat tire safely.

5-38 Rocking Your Vehicle To Get It Out
First, turn your steering wheel left and right. That will
clear the area around your front wheels. Then shift back
and forth between REVERSE (R) and a forward gear,
spinning the wheels as little as possible. Release the
accelerator pedal while you shift, and press lightly on
the accelerator pedal when the transmission is in gear.
By slowly spinning your wheels in the forward and
reverse directions, you will cause a rocking motion that
may free your vehicle. If that doesn't get you out after a
few tries, you may need to be towed out. Or, you can use
your recovery hooks if your vehicle has them. If you do
need to be towed out, see ªTowing Your Vehicleº in
the Index.
Using the Recovery Hooks
Your vehicle is equipped with recovery hooks. The
hooks are provided at the front of your vehicle. You may
need to use them if you're stuck off
-road and need to be
pulled to some place where you can continue driving.

6-20
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.
How to Check
Because this operation can be a little difficult, you
may choose to have this done at the dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading
on the dipstick.
NOTICE:
Too much or too little fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission fluid.

Scheduled Maintenance
7-11
50,000 Miles (83 000 km)

Change automatic transmission fluid and filter if the vehicle is mainly driven
under one or more of these conditions:
± In heavy city traffic where the outside temperature regularly reaches
90
F (32
C) 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 at 100,000 miles (166 000 km).
52,500 Miles (87 500 km)
Check rear/front axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking.
Rotate tires. See ªTire Inspection and Rotationº in the Index for proper
rotation pattern and additional information. (See footnote +.)
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE

Scheduled Maintenance
7-14
97,500 Miles (162 500 km)

Check rear/front axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking.

Rotate tires. See ªTire Inspection and Rotationº in the Index for proper
rotation pattern and additional information. (See footnote +.)
100,000 Miles (166 000 km)

Inspect spark plug wires.
An Emission Control Service.

Replace spark plugs.
An Emission Control Service.

Change automatic transmission fluid and filter if the vehicle is mainly driven
under one or more of these conditions:
± In heavy city traffic where the outside temperature regularly reaches
90
F (32
C) or higher.
± In hilly or mountainous terrain.
± When doing frequent trailer towing.
± Uses such as found in taxi, police or delivery service.
If you haven't used your vehicle under severe service conditions listed
previously and, therefore, haven't changed your automatic transmission
fluid, change both the fluid and filter.
Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE

8-6
Roadside Assistance
GMC's Roadside Assistance provides stranded owners
with over
-the-phone roadside repairs, location of the
nearest GMC dealer or the following special services:
Flat Tire Change: Installation of spare tire will be
covered at no charge (customer is responsible for repair
or replacement of tire).Fuel Delivery: Delivery of enough fuel for the customer
to get to the nearest service station (up to $5.00) will
be covered.
Jump Start: No
-start situations which require a battery
jump start will be covered at no charge.
Lock Out: Replacement keys or locksmith service will
be covered at no charge if you are unable to gain entry
into your vehicle. Delivery of the replacement key will
be covered at no charge within 10 miles (16 km).
Emergency Towing Service: Towing to the nearest
GMC dealer for warranty related disablements will
be covered.
Trip Routing: Custom
-made, computerized highlighted
maps using the most direct or scenic route are provided
free of charge. Maps include points of interest and a list
of GMC dealers along the route. Also included is a list
of hotels along the route that are discounted through
affiliation with ªQuest International.º Trip Routing
is available through Roadside Assistance by calling
1
-800-GMC-8782 (462-8782). Please be prepared
to provide your Vehicle Identification Number (VIN).
Allow five working days for fulfillment.