Page 300 of 376

Fuse Usage
16 Airbag System
17 Exterior/Interior Lamps
18 Parking Brake
19 Accessory Power
20 Ignition 4
21 Sidemarker Lamps
22 Turn Signal/Backup Lamps
23 Transmission
24 Hydraulics/Air Brake
A Spare
B Spare
Fuse Usage
Blank Not Used
BRK Brake Warning Lamp
RT PRK Passenger Side Parking Lamps
Blank Not Used
Blank Not Used
LT PARK Driver Side Parking Lamps
RT REAR
TRN/STOPPassenger Side Rear Turn
Signal/Stoplamp
LT REAR
TRN/STOPDriver Side Rear Turn
Signal/Stoplamp
Fuse Usage
RADIO Radio
Blank Not Used
Blank Not Used
PWR WNDW Power Windows
Relay Usage
ECU/PTO*Engine Control Unit/Power Take-Off
*Diesel 7.8 Duramax
BRK LAMPC4/C5 Brake Lamps,
C6/C7/C8 Tractor/Trailer Wiring
DRL Daytime Running Lamps
IGN-4 Ignition
CHMSL Center High Mounted Stoplamp
MRK LTS Sidemarker and Clearance Lamps
HTD/MIRR Heated Mirrors
HTR Diesel Heated Fuel
RT TRN TRLR Passenger Side Trailer Turn Signal
Blank Not Used
LT TRN TRLR Driver Side Trailer Turn Signal
Blank Not Used
Blank Not Used
Blank Not Used
5-98
Page 302 of 376
Fuse Usage
PCM-B Powertrain Control Module
TCM Transmissions (LF8)
ENG 4 Engine 4 (LMM/LF6/LF8)
ENG 2 Engine 2 (L18/LMM)
HTD FUEL Heated Fuel (LMM)
BLANK Not Used
BLANK Not Used
NOTE 3 Fan Relay (LMM), Emissions (L18)
A/C COMP Air Conditioning Compressor
ABS 1 Antilock Brake System 1
ABS 2 Antilock Brake System 2
ABS 3 Antilock Brake System 3
ENGINE Engine
E/A PUMP Electronic/Automatic Pump
HORN Horn
NOTE 2Fuel (L18/LMM), Electronic Control
Module (LF6)Fuse Usage
NOTE 4 Electronic Control Module (LF6)
STUD A Spare
STUD B Spare
Relay Usage
NOTE 1 LMM/L18 Fuel Pump Relay
IGN B RELAY Ignition Relay
STARTER
RELAYStarter Relay
HORN RELAY Horn Relay
IGN A RELAY Ignition Relay
PTO/ECU*
RELAYPower Take-Off/Engine Control Unit
(*Diesel 7.8L LF8)
REVERSE
RELAYReverse Relay
FAN RELAY Fan Relay (LMM)
5-100
Page 303 of 376
Fuse Usage
IGN 1 Ignition 1
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
5-101
Page 363 of 376

OnStar®(Isuzu 7.8L L6 Engine)
If your vehicle has OnStar and you subscribe to the
OnStar services, please refer to the OnStar Terms and
Conditions for information on data collection and use.
Navigation System (Isuzu
7.8L L6 Engine)
If your vehicle has a navigation system, use of the
system may result in the storage of destinations,
addresses, telephone numbers, and other trip
information. Refer to the navigation system operating
manual for information on stored data and for deletion
instructions.
Radio Frequency Identification
(RFID) (Isuzu 7.8L L6 Engine)
RFID technology is used in some vehicles for functions
such as tire pressure monitoring and ignition system
security, as well as in connection with conveniences
such as key fobs for remote door locking/unlocking and
starting, and in-vehicle transmitters for garage door
openers. RFID technology in GM vehicles does not use
or record personal information or link with any other
GM system containing personal information.
7-13
Page 370 of 376

G
Gage
Air Pressure...............................................3-47
Check Gages Warning Light..........................3-43
Engine Coolant Temperature.........................3-34
Filter Minder...............................................3-46
Fuel..........................................................3-44
Hourmeter..................................................3-47
Oil Pressure...............................................3-38
Speedometer..............................................3-25
Tachometer.................................................3-25
Transmission Temperature.............................3-40
Voltmeter Gage...........................................3-30
Gasoline
Octane........................................................ 5-6
Specifications............................................... 5-7
Gasoline Engine, Starting.................................2-12
GM Mobility Reimbursement Program.................. 7-5
H
Hazard Warning Flashers................................... 3-6
Headlamp Wiring............................................5-95
Headlamps
Bulb Replacement.......................................5-71
Daytime Running Lamp................................3-15
Exterior Lamps............................................3-14
High/Low Beam Changer................................ 3-8
On Reminder..............................................3-14Heater...........................................................3-20
Engine Coolant...........................................2-25
High Idle System............................................2-20
Highbeam On Light.........................................3-42
Highway Hypnosis...........................................4-15
Hill and Mountain Roads..................................4-16
Hood
Checking Things Under................................5-22
Latches......................................................5-23
Horn ............................................................... 3-6
Hourmeter Gage.............................................3-47
How to Wear Safety Belts Properly...................1-16
I
Ignition Positions.............................................2-11
Infants and Young Children, Restraints...............1-32
Inflation - Tire Pressure...................................5-77
Instrument Panel
Brightness..................................................3-16
Cluster.......................................................3-24
Overview..................................................... 3-4
Switchbank.................................................3-18
J
Jump Starting.................................................5-62
6