Page 370 of 600

Q:What is total vehicle reserve capacity?
A:This is the difference between your GVWR and the
weight of your truck with full fuel and passengers.
It is the amount of weight you can add to your vehicle
before reaching your GVWR. Keep in mind that
reserve capacity numbers are intended as a guide
when selecting the amount of equipment or cargo
your truck can carry. If you are unsure of your
vehicle’s front, rear, or total weight, go to a weigh
station and weigh your vehicle. Your dealer can also
help you with this.
The total vehicle reserve capacity for your vehicle
can be found in the lower right corner of the
Certi cation/Tire label as shown previously.
See your dealer for additional advice and information
about using a snow plow on your vehicle. Also, see
Loading Your Vehicle on page 4-48.
Emergency Roof Lamp Provisions
Vehicles with the RPO VYU snow plow prep package
also have an emergency roof lamp provision package,
RPO TRW. Wiring for the emergency roof lamp is
provided in the B-pillar as shown. SeeAuxiliary Roof
Mounted Lamp on page 3-18for switch location.
A. Body Side Inner Panel
B. Emergency Roof Lamp Harness
4-58
Page 408 of 600

Auxiliary Battery
The auxiliary battery provision can be used to supply
electrical power to additional equipment that you
may choose to add, such as a slide-in camper.
If your vehicle has this
provision, this relay will be
located on the passenger’s
side of the vehicle, next
to the auxiliary battery.
When using this provision, connection should only be
made to the upper stud (A) of the relay. Do not make
connections to the lower stud (B) of the relay.
The auxiliary battery circuit is protected by a megafuse
located behind the auxiliary battery.
Be sure to follow the proper installation instructions that
are included with any electrical equipment that you install.Notice:Leaving electrical equipment on for
extended periods will drain the battery. Always turn
off electrical equipment when not in use and do not
use equipment that exceeds the maximum amperage
rating for the auxiliary battery provision.
Power Winches
If you wish to use a power winch on your vehicle, only
use it when your vehicle is stationary or anchored.
Trailer Recommendations
You must subtract your hitch loads from the CWR for your
vehicle. Weigh your vehicle with the trailer attached, so
that you won’t go over the GVWR or GAWR. If you are
using a weight-distributing hitch, weigh the vehicle
without the spring bars in place.
You’ll get the best performance if you spread out the
weight of your load the right way, and if you choose
the correct hitch and trailer brakes.
For more information, seeTowing a Trailer on
page 4-67.
4-96
Page 537 of 600
Fuses Usage
IGN 3 Ignition, Heated Seats
4WDFour-Wheel Drive System,
Auxiliary Battery
HTR A/C Climate Control System
LOCK (Relay)Power Door Lock Relay
(Lock Function)
HVAC 1 Climate Control System
LT DRDriver’s Door Harness
Connection
CRUISECruise Control, Power Take
Off (PTO)
UNLCK (Relay)Power Door Lock Relay
(Unlock Function)
RR FOG LP Not Used
BRAKE Anti-Lock Brake SystemFuses Usage
DRIVER UNLCKPower Door Lock Relay
(Driver’s Door Unlock
Function)
IGN 0 TCM
TBC IGN 0 Truck Body Controller
VEH CHMSLVehicle and Trailer High
Mounted Stoplamp
LT TRLR ST/TRN Left Turn Signal/Stop Trailer
LT TRNLeft Turn Signals and
Sidemarkers
VEH STOPVehicle Stoplamps, Brake
Module, Electronic Throttle
Control Module
RT TRLR ST/TRN Right Turn Signal/Stop Trailer
RT TRNRight Turn Signals and
Sidemarkers
5-125
Page 538 of 600
Fuses Usage
BODY Harness Connector
DDM Driver Door Module
AUX PWR 2, M/GATE Not Used
LCKS Power Door Lock System
ECC, TPMTire Pressure Monitoring
System
TBC 2C Truck Body Controller
HAZRD Flasher Module
CB LT DRSLeft Power Windows
Circuit Breaker
TBC 2B Truck Body Controller
TBC 2A Truck Body ControllerCenter Instrument Panel Fuse Block
The center instrument panel utility block is located
underneath the instrument panel, to the left of the
steering column.
Device Usage
SEO Special Equipment Option
TRAILER Trailer Brake Wiring
UPFIT Up tter (Not Used)
5-126
Page 541 of 600

*1Fuel Injection Rail #2-Gasoline Engine; Engine
Control Module-Diesel Engine.
*2Fuel Injection Rail #1-Gasoline Engine;
Actuator-Diesel Engine.
*3Oxygen Sensors-Gasoline Engine; Fuel Heater-Diesel
Engine.
*4Oxygen Sensors-Gasoline Engine; Engine Control
Module 1-Diesel Engine.
*5Ignition 1-Gasoline Engine; Engine Control
Module-Diesel Engine.
*6Powertrain Control Module B-Gasoline Engine;
Engine Control Module B-Diesel Engine.
*7Rear Climate Control.
*8Sunroof.
Fuses Usage
GLOW PLUGDiesel Glow Plugs and
Intake Air Heater
CUST FEED Gasoline Accessory Power
HYBRID Hybrid
STUD #1Auxiliary Power (Single
Battery and Diesels Only)/
Dual Battery (TP2) Do not
install fuse.
Fuses Usage
MBECMid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLWR Front Climate Control Fan
LBECLeft Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power Outlet—Rear
Cargo Area and Instrument
Panel
STUD #2*Accessory Power/Trailer
Wiring Brake Feed
ABS Anti-lock Brakes
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
5-129
Page 542 of 600
Fuses Usage
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STRTR Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller Battery
Feed
SEO B2 Off-Road Lamps
4WS Not Used
AUX PWRAuxiliary Power Outlet —
Console
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake
Controller-Gasoline Engine,
Fan Clutch-Diesel Engines
IGN EInstrument Panel Cluster,
Air Conditioning Relay,
Turn Signal/Hazard Switch,
Starter RelayFuses Usage
RTD Ride Control
TRL B/U Backup Lamps Trailer Wiring
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
AIRBAGSupplemental In atable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
DRLDaytime Running Lamps
(Relay)
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LT High Beam Headlamp-Left
LH HID Not Used
5-130
Page 544 of 600
Auxiliary Electric Cooling Fan
Fuse Block
The auxiliary electric
cooling fan fuse block is
located in the engine
compartment on the
driver’s side of the vehicle
next to the underhood
fuse block.
Lift the cover for access to the fuse/relay block.
Fuses Usage
COOL/FAN Cooling Fan
COOL/FAN Cooling Fan Relay Fuse
COOL/FAN Cooling Fan Fuse
Relays Usage
COOL/FAN 1 Cooling Fan Relay 1
COOL/FAN 3 Cooling Fan Relay 3
COOL/FAN 2 Cooling Fan Relay 2
5-132
Page 588 of 600

Audio System(s) (cont.)
Radio with Cassette and CD.........................3-85
Radio with CD............................................3-75
Radio with Six-Disc CD..............................3-100
Rear Seat Audio (RSA)...............................3-127
Setting the Time for Radios with
Radio Data Systems (RDS).......................3-71
Setting the Time for Radios without
Radio Data Systems (RDS).......................3-71
Theft-Deterrent Feature...............................3-129
Understanding Radio Reception...................3-130
XM™ Satellite Radio Antenna System...........3-133
Automatic Headlamp System............................3-15
Automatic Transmission
Fluid..................................................5-28, 5-30
Operation...................................................2-26
Auxiliary Roof Mounted Lamp Switch.................3-18
B
Battery..........................................................5-51
Battery Warning Light......................................3-40
Before Leaving on a Long Trip.........................4-38
Brake
Anti-Lock Brake System (ABS)........................ 4-6
Emergencies................................................ 4-8
Parking......................................................2-52
System Warning Light..................................3-41
Brakes..........................................................5-47
Braking........................................................... 4-5Braking in Emergencies..................................... 4-8
Break-In, New Vehicle.....................................2-21
Bulb Replacement...........................................5-63
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp............................................5-67
Front Turn Signal, Sidemarker and Daytime
Running Lamps........................................5-64
Halogen Bulbs............................................5-63
Headlamps.................................................5-63
Pickup Box Identi cation and Fender
Marker Lamps.........................................5-68
Replacement Bulbs......................................5-70
Roof Marker Lamps.....................................5-66
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps........................................5-68
Buying New Tires...........................................5-84
C
California Fuel.................................................. 5-7
California Proposition 65 Warning....................... 5-4
Canadian Owners................................................ ii
Capacities and Speci cations..........................5-133
Carbon Monoxide...................2-14, 2-57, 4-42, 4-67
Care of
Safety Belts..............................................5-116
Your Cassette Tape Player..........................3-131
Your CD and DVD Player...........................3-132
Your CDs and DVDs..................................3-132
Cargo Lamp...................................................3-19
2