
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 and diesel engines,
and on the thermostat housing on the 8.1L
engine. On V8 engines it is marked″GND.″
SeeEngine Compartment Overview on page 5-12
for more information on location.
{CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing
this, and some have been blinded. Use a
flashlight if you need more light.
Be sure the battery has enough water. You
don’t need to add water to the ACDelco
®
battery installed in your new vehicle. But if a
battery hasfiller caps, be sure the right
amount offluid is there. If it is low, add water
to take care of thatfirst. If you don’t, explosive
gas could be present.
Batteryfluid contains acid that can burn you.
Don’t get it on you. If you accidentally get it in
your eyes or on your skin,flush the place with
water and get medical help immediately.
5-41
2003 - Sierra Denali

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.3. Insert the hoist end
(open end) (F) of the
extension through
the hole (G) in the rear
bumper.
Be sure the hoist end of the extension connects to
the hoist shaft (E). The ribbed square end of the
extension is used to lower the spare tire.
4. Turn the wheel wrench (H) counterclockwise to
lower the spare tire to the ground. Continue to
turn the wheel wrench until the spare tire can be
pulled out from under the vehicle.
If the spare tire does not lower to the ground, the
secondary latch is engaged causing the tire
not to lower. See“Secondary Latch System”later in
this section.
5-67
2003 - Sierra Denali

Instrument Panel Fuse Block
The fuse block access
door is on the driver’s side
edge of the instrument
panel. Pull off the cover to
access the fuse block.
To remove fuses, hold the end of the fuse between your
thumb and indexfinger and pull straight out.
You may have spare fuses located behind the fuse
block access door. These can be used to replace a bad
fuse. However, make sure it is of the correct amperage.
Fuses Usage
RR Wiper Not Used
SEO ACCYSpecial Equipment Option
Accessory
WS WPR Windshield Wipers
TBC ACCYTruck Body Controller
Accessory
IGN 3 Ignition, Heated Seats
5-92
2003 - Sierra Denali

*1—Gasoline Engine and Diesel Engine.
*2—Gasoline Engine; ECMRPV—Diesel Engine.
*3—Gasoline Engine; FUEL HT—Diesel Engine.
*4—Gasoline Engine; ECM I—Diesel Engine.
*5—IGN/EDU
Fuses Usage
GLOW PLUGDiesel Glow Plugs and Intake
Air Heater
CUST FEED Gasoline Accessory Power
STUD #1Auxiliary Power (Single
Battery and Diesels Only)/
Dual Battery (TP2) Do not
install fuse.
MBECMid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLOWER Front Climate Control Fan
LBECLeft Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power Outlet—Rear
Cargo Area and Instrument
Panel
STUD 2Accessory Power/Trailer
Wiring Brake Feed
ABS Anti-Lock Brakes
Fuses Usage
VSES/ECAS Vehicle Stability
IGN A Ignition Power
IGN B Ignition Power
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKRight Rear Parking and
Sidemarker Lamps
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STARTER Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller
Battery Feed
SUNROOF Sunroof
SEO B2 Off-Road Lamps
4WSVent Solenoid
Canister/Quadrasteer Module
Power
RR HVAC Not Used
AUX PWRAuxiliary Power
Outlet—Console
5-97
2003 - Sierra Denali

Fuses Usage
IGN 1 Ignition Relay
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake Controller
IGN EInstrument Panel Cluster, Air
Conditioning Relay, Turn
Signal/Hazard Switch, Starter
Relay
RTD Ride Control
TRL B/U Backup Lamps Trailer Wiring
PCM BPowertrain Control Module,
Fuel Pump
F/PMP Fuel Pump (Relay)
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control System
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
02B Oxygen Sensors
SIRSupplemental Inflatable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
DRLDaytime Running Lamps
(Relay)Fuses Usage
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LT High Beam Headlamp-Left
LH HID Not Used
DRL Daytime Running Lamps
IPC/DICInstrument Panel
Cluster/Driver Information
Center
HVAC/ECAS Climate Control Controller
CIG LTR Cigarette Lighter
HI HDLP-RT High Beam Headlamp-Right
HDLP-LOW Headlamp Low Beam Relay
A/C COMP Air Conditioning Compressor
A/C COMPAir Conditioning Compressor
Relay
RR WPR Not Used
RADIO Audio System
SEO B1Mid Bussed Electrical Center,
Rear Heated Seats,
HomeLink
LO HDLP-LT Headlamp Low Beam-Left
BTSIBrake Transmission Shift
Interlock System
CRANK Starting System
LO HDLP-RT Headlamp Low Beam-Right
5-98
2003 - Sierra Denali

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.
The key should turn to LOCK only when the
shift lever is in PARK (P).
The key should come out only in LOCK.
Parking Brake and Automatic
Transmission Park (P) Mechanism
Check
{CAUTION:
When you are doing this check, your vehicle
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.
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 ush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
6-13
2003 - Sierra Denali

H
Hazard Warning Flashers................................... 3-4
Head Restraints............................................... 1-5
Headlamp High/Low Beam Changer.................... 3-6
Headlamps....................................................5-48
Bulb Replacement.......................................5-48
Front Turn Signal, Sidemarker and Daytime
Running Lamps........................................5-49
Halogen Bulbs............................................5-48
Pickup Box Identification and Fender
Marker Lamps.........................................5-54
Roof Marker Lamps.....................................5-51
Heated Seats................................................... 1-3
Heating.........................................................3-22
Highway Hypnosis...........................................4-38
Hill and Mountain Roads..................................4-38
Hitches..........................................................4-57
HomeLink
®Transmitter, Programming................2-35
HomeLink®Transmitter....................................2-35
Hood
Checking Things Under................................5-10
Release.....................................................5-10
Horn ............................................................... 3-5
How to Add Coolant to the Coolant Surge Tank......5-30
How to Add Fluid............................................5-22
How to Check........................................5-20, 5-57
How to Check Lubricant...................................5-46
How to Check Power Steering Fluid..................5-35How to Inspect...............................................5-18
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-12
Hydroplaning..................................................4-33
I
If No Steam Is Coming From Your Engine..........5-28
If Steam Is Coming From Your Engine...............5-27
If the Light is Flashing.....................................3-38
If the Light Is On Steady.................................3-38
If You Are Stuck in Sand, Mud, Ice or Snow.......4-44
If You Do Decide To Pull A Trailer.....................4-53
If You’re Caught in a Blizzard...........................4-42
Ignition Positions.............................................2-16
Ignition Transmission Lock Check......................6-13
Illuminated Visor Vanity Mirrors.........................2-13
Infants and Young Children, Restraints...............1-31
Inflation -- Tire Pressure..................................5-57
Inspection
Brake System
.............................................6-15
Engine Cooling System
................................6-14
Exhaust System
..........................................6-14
Fuel System
...............................................6-14
Part C - Periodic Maintenance
.......................6-14
Steering and Suspension
..............................6-14
Transfer Case and Front Axle
(All-Wheel Drive)
......................................6-15
7
2003 - Sierra Denali