Page 121 of 398

Instrument Panel Overview...............................3-4
Hazard Warning Flashers................................3-6
Other Warning Devices...................................3-6
Horn .............................................................3-6
Tilt Wheel.....................................................3-7
Turn Signal/Multifunction Lever.........................3-7
Turn and Lane-Change Signals........................3-8
Headlamp High/Low-Beam Changer..................3-8
Windshield Wipers..........................................3-9
Windshield Washer.......................................3-10
Cruise Control..............................................3-10
Exterior Lamps.............................................3-14
Headlamps on Reminder................................3-15
Daytime Running Lamps (DRL).......................3-15
Marker Lamps..............................................3-16
Instrument Panel Brightness...........................3-16
Dome Lamps ...............................................3-16
Entry Lighting...............................................3-17
Reading Lamps............................................3-17
Instrument Panel Switchbank..........................3-18
Accessory Power Outlet(s).............................3-19
Ashtray(s) and Cigarette Lighter......................3-20Climate Controls............................................3-20
Climate Control System.................................3-20
Outlet Adjustment.........................................3-24
Rear Heating System....................................3-24
Warning Lights, Gages, and Indicators............3-25
Instrument Panel Cluster................................3-26
Speedometer and Odometer...........................3-27
Trip Odometer..............................................3-27
Tachometer.................................................3-27
Engine Speed Limiter....................................3-28
Safety Belt Reminder Light.............................3-28
Safety Belt Reminder Tone............................3-28
Airbag Readiness Light..................................3-29
Airbag Off Light............................................3-30
Charging System Light..................................3-31
Voltmeter Gage............................................3-32
Service Transmission Warning Light................3-32
Range Inhibit Warning Indicator......................3-33
Brake System Warning Light..........................3-33
Anti-Lock Brake System Warning Light.............3-35
Trailer Anti-Lock Brake System Warning Light . . .3-36
Engine Coolant Temperature Gage..................3-36
Section 3 Instrument Panel
3-1
Page 126 of 398

Hazard Warning Flashers
The hazard warning flashers warn others. They also let
police know you have a problem. Your front and rear
turn signal lamps will flash on and off.
The hazard warning
flasher button is
located on top of the
steering column.
The hazard warning flashers work no matter what
ignition position the key is in, and even if the key is not
in the ignition.
Press the button to make the front and rear turn signal
lamps flash on and off. Press the button again to
turn the flashers off.
When the hazard warning flashers are on, your turn
signals will not work.
Other Warning Devices
If you carry reflective triangles, you can set them up at
the side of the road about 300 feet (100 m) behind
your vehicle.
Horn
Sound the horn by pushing the center of the steering
wheel. If you have the optional air horn, it is controlled
by a cord that you will find up above and to the left
of the driver. The harder you pull on the cord, the louder
the air horn will sound. The air horn works only after
your air brake system pressure gets up to about 115 psi
(790 kPa). The air horn will work properly unless the
air brake system pressure drops below 60 psi (415 kPa).
3-6
Page 281 of 398

Electric Air Compressor
Your vehicle may have an electric air compressor. This
compressor is used to run options that require
pressurized air, such as air horn, air seat, 7.8L engine
exhaust restrictor, or 7.8L engine exhaust brake.
The air compressor is used when vehicles are not
equipped with an air brake system.
The air supply for this
system must be
maintained by releasing
the drain valve to eject any
moisture that may have
built up in the system.
It is recommended that this system be drained on a
weekly basis.
Clutch Pedal Free Travel
If you have a V8 engine and a manual transmission,
your clutch will need adjustment when pedal free travel
gets down to about 1/4 inch (32 mm), as measured
at the clutch pedal pad. You should have 1 1/2 to
2 inches (38 to 51 mm) of clutch pedal free travel.
If your clutch ever needs service, be sure to use only
GM clutch replacement parts.
Chassis Lubrication
Your Maintenance Schedule provides all of the required
chassis lubrication intervals and identifies proper
lubricants to use. Be sure to see your Maintenance
Schedule before performing any chassis lubrication
service. To determine location of chassis lubrication
items, use the following charts.
5-53
Page 325 of 398
Fuse Usage
RR DEFOG Rear Defog
ENG 1 Engine 1
ENG 3 Engine 3
PCM-B Powertrain Control Module
BLANK Not Used
Fuse Usage
ENG 4 Engine 4
ENG 2 Engine 2
HTD FUEL Heated Fuel
BLANK Not Used
BLANK Not Used
02A Emissions
A/C COMP Air Conditioning Compressor
ABS 1 Anti-lock Brake System 1
ABS 2 Anti-lock Brake System 2
ABS 3 Anti-lock Brake System 3
ENGINE Engine
E/A PUMP Electronic/Automatic Pump
HORN Horn
NOTE 2L18 Fuel, LG4 Powertrain Control
Valve, LG5 Electronic Control
Module
NOTE 3L18 Fuel, LG4 Powertrain Control
Valve, LG5 Electronic Control
Module
STUD A Spare
STUD B Spare Primary Underhood Fuse Block
5-97
Page 326 of 398
Relay Usage
NOTE 1LG4 Powertrain Control Valve,
L18 Fuel Pump, LG5 Heated Fuel
IGN B Ignition
STARTER Starter
HORN Horn
IGN A Ignition
PTO/ECU*Power Take-Off/Engine Control Unit
*Diesel 7.8L DURAMAX
®
REVERSE Reverse
NEUTRAL
STARTNeutral Start
Fuse Usage
IGN 1 Four-Wheel Drive Module
IGN 4 Ignition 4
IGN 3 Ignition 3
BATT/HAZ Battery/Hazard Warning Flashers
HEADLAMP Headlamps
LIGHTING Interior/Exterior Lamps
HVAC Climate Control System
NOTEC4/C5 Electric Brake,
C6/C7/C8 Brake Lamps Secondary Underhood
Fuse Block
5-98
Page 391 of 398

H
Hazard Warning Flashers................................... 3-6
Headlamp Wiring............................................5-93
Headlamps
Bulb Replacement.......................................5-68
Daytime Running Lamps...............................3-15
High/Low Beam Changer................................ 3-8
On Reminder..............................................3-15
Heater...........................................................3-20
High Idle System............................................2-21
Highbeam On Light.........................................3-43
Highway Hypnosis...........................................4-25
Hill and Mountain Roads..................................4-26
Hood
Checking Things Under................................5-22
Latches......................................................5-22
Horn ............................................................... 3-6
Hourmeter Gage.............................................3-47
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-14
Hydraulic Brake Systems................................... 4-7
Hydraulic Brakes.............................................2-40
I
Ignition Positions.............................................2-12
Infants and Young Children, Restraints...............1-31
Inflation - Tire Pressure...................................5-75
Instrument Panel
Overview..................................................... 3-4
Switchbank.................................................3-18
Instrument Panel (I/P)
Brightness..................................................3-16
Cluster.......................................................3-26
J
Jump Starting.................................................5-59
K
Keyless Entry System....................................... 2-3
Keys............................................................... 2-2
7