2003 GMC YUKON DENALI ignition

Automatic Level Control
The automatic level control rear suspension comes as a
part of the AutorideTMsuspension. See AutorideTM on
page
4-46.
This type of level control is fully automatic and will
provide a better leveled riding position as well as better
handling under a variety of passenger and loading
conditions. An air compressor connected
to the rear
shocks will raise or lower the rear of the vehicle
to maintain proper vehicle height. The system is
activated when the ignition key
is turned to RUN and
will automatically adjust vehicle height thereafter.
The system may exhaust (lower vehicle height) for up
to
10 minutes after the ignition key has been turned to
OFF. You may hear the air compressor operating when
the height is being adjusted.
If a weight-distributing hitch is being used, it is
recommended
to allow the shocks to inflate, thereby
leveling the vehicle prior to adjusting the height.
AutorideTM
The AutorideTM feature provides superior vehicle ride
and handling under a variety
of passenger and loading
conditions.
The system is fully automatic and
uses a computer
controller
to continuously monitor vehicle speed, wheel
to body position, IifVdive and steering position of the
vehicle. The controller then sends signals to each shock
absorber
to independently adjust the damping level to
provide the optimum vehicle ride.
AutorideTM also interacts with the towlhaul mode that,
when activated, will provide additional control of
the shock absorbers. This additional control results in
better ride and handling characteristics when the vehicle
is loaded or towing a trailer. See "Tow/Haul Mode"
under Towing a Trailer on page
4-47 for more
information.
4-46

How to Reset the CHANGE ENGINE OIL
Message
The GM Oil Life System calculates when to change
your engine oil and filter based on vehic!e
use. Anytime
your oil is changed, reset the system
so it can
calculate when the next oil change is required.
If a
situation occurs where you change your
oil prior to a
CHANGE ENGINE OIL message being turned on, reset
the system.
To reset the CHANGE ENGINE
OIL message, see “GM
Oil Life System” under DIC Operation and Displays
on page 3-43 for vehicles equipped with the DIC, or do
the following:
1. Turn the ignition key to RUN with the engine off.
2. Fully press and release the accelerator pedal three
If the OIL LIFE RESET message flashes for
10 seconds,
the system is reset.
If the system does not reset, try the procedure once
again. If it still does not reset, see your dealer for
service. times
within five seconds.
What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Don’t let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good hand cleaner. Wash
or properly dispose of clothing or
rags containing used engine oil. See the manufacturer’s
warnings about the use and disposal of oil products.
Used oil can be a threat
to the environment. If you
change your own oil, be sure
to drain all the oil from the
filter before disposal. Never dispose of oil by putting it
in the trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Instead, recycle it by
taking it to a place that collects used oil. If you have a
problem properly disposing of your used oil, ask
your dealer, a service station or a local recycling center
for help.
Engine Air Cleaner/Filter
The engine air cleanedfilter assembly has an air filter
restriction indicator that lets you know when the engine
air cleaner/filter is dirty and needs to be serviced.
The air filter restriction indicator is located on the air
filter assembly cover. See Engine Compartment
Overview
on page 5-72 for more information on location.
See Part
B: Owner Checks and Services on page 6-10
to determine when to check the air filter restriction
indicator.
5-1 7

Adding Washer Fluid
Your vehicle has a low washer fluid message that
comes on when the washer fluid
is low. The message is
displayed for
15 seconds at the star? of each ignition
cycle. When the LOW
WASHER FLUID message
is displayed, you will need to add washer fluid to the
windshield washer fluid reservoir.
The windshield washer
the engine compartment
toward the front of the
vehicle on the driver’s side.
4-4- fluid reservoir is located in 111
W
Open the cap with the washer symbol on it. Add washer
fluid until the tank is full.
Notice:
When using concentrated washer fluid, follow
the manufacturer’s instructions for adding water.
Don’t mix water with ready-to-use washer fluid.
Water can cause the solution to freeze and
damage your washer
fluid tank and other parts
of the washer system.
Also, water doesn’t
clean as well as washer fluid.
Fill your washer fluid tank only three-quarters
full when it’s very cold. This allows for expansion if freezing occurs, which could damage the tank if
it is completely full.
Don’t use engine coolant (antifreeze)
in your
windshield washer.
It can damage your
washer system and paint.
5-35

Notice: If the other system isn’t a 12-volt system
with a negative ground, both vehicles can be
damaged.
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 an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake.
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 accessory power outlets. Turn
off the
radio and all 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 under a red plastic cover near
the engine accessory drive
bracket.
To access the
remote positive
(+)
terminal, open the red
plastic cover.
5-41

A. Spare Tire (Valve Stem Pointed Up)
B. Hoist Assembly
C. Hoist Cable
D. Tire Retainer
E. Hoist Shaft
F. Hoist End of Extension Tool
G. Hoist Shaft Access Hole
H. Wheel Wrench
I. Jack Handle Extensions
J. Hoist Lock (If Equipped)
1. If your vehicle is equipped with a hoist lock (J),
open the spare tire lock cover on the bumper
and
use the ignition key to remove the lock.
2. Assemble the wheel wrench (H) and the two jack
handle extensions
(I) as shown.
5-66

*I - Gasoline Engine and Fuel Injection Rail #2.
*2 - Gasoline Engine and Fuel Injection Rail #l.
*3 - Gasoline Engine; Oxygen Sensors.
*4 - Gasoline Engine; Oxygen Sensors.
*5 - PCM Ignition
I Fuses I Usage I
I STUD #1 I
Battery-and Diesels
Only)/Dual Battery (TP2) Do
not -install fuse.
Mid Bussed Electrical Center
MBEC Power
Feed, Front Seats,
LBEC Door Modules, Door Locks,
Auxiliary Power Outlet-Rear
Cargo Area and Instrument
Panel
STUD 2 Accessory
Powerflrailer
Wirinq Brake Feed LBEC
1
~~
I RR PARK I
Right
Rear Parking and
Sidemarker LamDs
I
5-93

Fuses
RR HVAC
Usage
Rear Climate Control
AUX PWR I
Auxiliary Power
Outlet
- Console
IGN
1
PCM 1 Ignition Relay
Electronic Throttle Control,
ETC/ECM Powertrain Control Module
Electronic Brake Controller
IGN E Instrument Panel Cluster,
Air
Conditioning Relay, Turn
SignaVHazard Switch, Starter
Relav
RTD I Ride Control I
TRL B/U
~~
I Backup LampsTrailG Wiring 1
PCM B I
Powertrain Control Module,
Fuel Pumr,
I I
F/PMP I Fuel Pump (Relay)
B/U LP
I
Back-up Lamps, Automatic
Transmission Shift Lock
I
Control System
RR DEFOG
Rear Window Defoaaer
HDLP-HI
~~~ ____
HeadlampHighBeam Relay
PRIME Not Used
Fuses I Usage I
SIR Supplemental Inflatable
Restraint System
FRT PARK
DRL Front Parking Lamps,
Sidemarker Lamps
Daytime Running Lamps
(Relav)
SEO IGN
Truck Body Controller Ignition
TBC IGN1 Rear
Defog Relay
HI HDLP-LT High
Beam Headlamp-Left
LH HID Not
Used
DRL
I Davtime Runnina LamDs I
Instrument Panel
IPC/DIC Cluster/Driver Information
HI HDLP-RT
HDLP-LOW High
Beam Headlamp-Right
Headlamp Low Beam Relav
A/C COMP
I Air Conditionina Comm-essor I v
A/C COMP Air
Conditioning Compressor
Relav
5-94

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition key
to LOCK in each shift lever position.
0 The key should turn to LOCK only when the
The key should come out only in LOCK.
shift
lever is in PARK (P).
Parking Brake and Automatic
Transmission Park
(P) Mechanism
Check
WI..,.J you are doin, ,his cl.,:k, your --hide
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front
of your vehicle in
case it begins to roll. Be ready to apply the
regular brake at once should the vehicle begin
to move.
Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake, set the
parking brake.
To check the parking brake’s holding ability: With
the engine running and transmission in NEUTRAL
(N), slowly remove foot pressure from the regular
brake pedal. Do this until the vehicle is held by the
parking brake only.
0 To check the PARK (P) mechanism’s holding
ability: With the engine running, shift to PARK (P).
Then release the parking brake followed by the
regular brake.
Underbody Flushing Service
At least every spring, use plain water to flush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
6-1 3