transfer case GMC YUKON 2002 User Guide

2-93 Change Engine Oil
This message is displayed
when the engine oil needs
to be changed. The message
is only displayed for
15 seconds at the start
of each ignition cycle.
When you change the engine oil, be sure to reset the
Engine Oil Life System. See ªEngine Oil, When to
Changeº in the Index.
Security
This message is displayed
when the content
theft
-deterrent system
(if equipped) has been
activated and also monitors
the Passlock

System.
If the security message is displayed continuously while
driving and stays on, there may be a problem with the
Passlock System. Your vehicle will not be protected by
Passlock, and you should contact your GM dealer.
Service 4WD (If Equipped)
If the SERVICE 4WD
message comes on, there
may be a problem with the
automatic transfer case and
service is required.
Malfunctions can be indicated by the system before
any problem is apparent, which may prevent serious
damage to the vehicle. This system is also designed to
assist your service technician in correctly diagnosing
a malfunction.
Low Washer Fluid
This message is displayed
when the vehicle is low on
windshield washer fluid.
The message is only
displayed for 15 seconds
at the start of each
ignition cycle.
For more information, see ªWindshield Washer Fluidº in
the Index.

4-28
Q:Suppose, after stalling, I try to back down
the hill and decide I just can't do it. What
should I do?
A:Set the parking brake, put your transmission in
PARK (P) and turn off the engine. Leave the
vehicle and go get some help. Exit on the uphill
side and stay clear of the path the vehicle would
take if it rolled downhill. Do not shift the transfer
case to NEUTRAL when you leave the vehicle.
Leave it in some gear.
CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the transmission
is in PARK (P). This is because the NEUTRAL
position on the transfer case overrides the
transmission. You or someone else could be
injured. If you are going to leave your vehicle,
set the parking brake and shift the transmission
to PARK (P). But do not shift the transfer case
to NEUTRAL. Leave the transfer case in the
2 Wheel High, 4 High or 4 Low position.

4-51
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
ªFour
-Wheel Driveº in the Index for the proper
procedure to select the NEUTRAL position for
your vehicle.
5. Release the parking brake only after the vehicle
being towed is firmly attached to the towing vehicle.
6. Turn the ignition off.
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). You or
others could be injured. Make sure the parking
brake is firmly set before you shift the transfer
case to NEUTRAL.

4-68
5. If you have a four-wheel-drive vehicle, be sure the
transfer case is in a drive gear and not in NEUTRAL.
6. Release the regular brakes.
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 firmly 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 firmly 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
-- not
in NEUTRAL.
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.

5-4
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 firmly on both vehicles involved in
the jump start procedure. Put the automatic
transmission in PARK (P), or a manual transmission
in NEUTRAL (N) before setting the parking brake.
If you have a four
-wheel-drive vehicle, be sure the
transfer case is in a drive gear not in NEUTRAL.
NOTICE:
If you leave your radio on, it could be badly
damaged. The repairs wouldn't be covered by
your warranty.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or in the accessory power outlets. Turn off the
radio and all the lamps that aren't needed. This will
avoid sparks and help save both batteries. And it
could save your radio!
4. Open the hoods and locate the positive (+) and
negative (
-) terminal locations of the other vehicle.
Your vehicle has a remote positive (+) jump starting
terminal and a remote negative (
-) jump starting
terminal. You should always use these remote
terminals instead of the terminals on the battery.
The remote positive (+) terminal is located behind
a red plastic cover near the engine accessory drive
bracket. To uncover the remote positive (+) terminal,
open the red plastic cover.
The remote negative (
-) terminal is located on
the engine drive bracket on all V8 diesel engines.
On V8 engines it is marked ªGND.º
On V6 engines the remote negative (
-) terminal is
located on a tab attached to the engine accessory
drive bracket where it is marked ªGND.º
See ªEngine Compartment Overviewº in the Index
for more information on location.

6-28 How to Check Lubricant
1500 Series shown, 2500 and 3500 Series similar
To get an accurate reading, the vehicle should be on a
level surface.
The proper level for the 1500 Series is from 5/8 inch to
1 5/8 inch (15 mm to 40 mm) below the bottom of the
filler plug hole. The proper level for the 2500 Series is
from 0 to 3/8 inch (0 to 10 mm) below the bottom of the
filler plug hole. Add only enough fluid to reach the
proper level.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.
Four-Wheel Drive
Lubricant checks in this section also apply to these
vehicles. However, there are two additional systems that
need lubrication.
Transfer Case
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See ªPeriodic Maintenance
Inspectionsº in the Index.

6-29
How to Check Lubricant
Automatic Transfer Case
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the bottom of the filler plug hole,
you'll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of the filler plug hole.
Use care not to overtighten the plug.What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.
Front Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See ªScheduled
Maintenance Servicesº in the Index.

6-76
Fuse Usage
ATC Automatic Transfer Case
RR DEFOG Rear Window Defogger, Heated
Mirrors (Relay)
RTD Autoride
(Real Time Damping)
RR PRK Right Rear Parking Lamps
ECM B PCM
F/PMP Fuel Pump (Relay)
O2 A Oxygen Sensors
O2 B Oxygen Sensors
LR PRK Left Rear Parking Lamps
RR DEFOG Rear Window Defogger,
Heated Mirrors
HDLP Headlamps (Relay)
TRL PRK Parking Lamps Trailer Wiring
PRIME Not Used
RT HDLP Right Headlamps
DRL Daytime Running Lamps (Relay)
HTD MIR Heated MirrorsFuse Usage
LT HDLP Left Headlamps
A/C Air Conditioning
AUX PWR Cigarette Lighter, Auxiliary
Power Outlets
SEO 2 Special Equipment Option Power,
Power Seats, Aux Roof Mnt Lamp
SEO 1 Special Equipment Option
Power, Aux Roof Mnt Lamp,
Cell Phone, OnStar


DRL Daytime Running Lamps
A/C A/C (Relay)
FOG LP Fog Lamps
FOG LP Fog Lamps (Relay)
RADIO Audio System, Instrument Cluster,
Climate Control System
CIGAR Cigarette Lighter, Auxiliary
Power Outlets
RT TURN Right Turn Signals
BTSI Automatic Transmission Shift
Lock Control System

Scheduled Maintenance
7-6Engine Oil and Chassis Lubrication
Scheduled Maintenance
Change engine oil and filter as indicated by the
GM Oil Life System (or every 12 months,
whichever occurs first). Reset the system.
Your vehicle has a computer system that lets you know
when to change the engine oil and filter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change will be indicated can vary
considerably. For the oil life system to work properly,
you must reset the system every time the oil is changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE ENGINE OIL message will
come on. Change your oil as soon as possible within the
next two times you stop for fuel. It is possible that, if
you are driving under the best conditions, the oil lifesystem may not indicate that an oil change is necessary
for over a year. However, your engine oil and filter must
be changed at least once a year and at this time the
system must be reset. It is also important to check your
oil regularly and keep it at the proper level.
If the system is ever reset accidentally, you must change
your oil at 3,000 miles (5 000 km) since your last oil
change. Remember to reset the oil life system whenever
the oil is changed. See ªOil Life Systemº in the Index
for information on resetting the system.
An Emission Control Service.
Lubricate chassis components with each engine oil and
filter change. Lubricate the front suspension, ball joints,
steering linkage, transmission shift linkage, transfer case
shift linkage, and parking brake cable guides. Ball joints
should not be lubricated unless their temperature is
10
F (
-12
C) or higher, or they could be damaged.

Scheduled Maintenance
7-11
45,000 Miles (75 000 km)

If Equipped: Replace passenger compartment air filter. If you drive regularly
under dusty conditions, the filter may require replacement more often.

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 +.)
50,000 Miles (83 000 km)

Change automatic transmission fluid and filter filter if the vehicle's GVWR
is over 8600 lbs. or 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).
Change transfer case fluid.
ACTUAL
SERVICED BY:MILEAGE
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ACTUAL
SERVICED BY:MILEAGE
DATE