Page 531 of 588

*1Ð Gasoline Engine and Diesel Engine.
*2Ð Gasoline Engine; ECMRPV Ð Diesel Engine.
*3Ð Gasoline Engine; FUEL HT Ð Diesel Engine.
*4Ð Gasoline Engine; ECM I Ð Diesel Engine.
*5Ð 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 OutletÐRear
Cargo Area and Instrument
Panel
Fuses Usage
STUD 2Accessory 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
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
5-131
Page 532 of 588

Fuses Usage
SUNROOF Sunroof
SEO B2 Off-Road Lamps
4WSVent Solenoid
Canister/Quadrasteer Module
Power
RR HVAC Not Used
AUX PWRAuxiliary Power Outlet Ð
Console
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)Fuses Usage
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 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
DRL Daytime Running Lamps
IPC/DICInstrument Panel
Cluster/Driver Information
Center
5-132
Page 549 of 588

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.
Contact your GM Goodwrench dealer if service is
required.
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.
Contact your GM Goodwrench dealer if service is
required.
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
Page 578 of 588

Headlamps (cont.)
Front Turn Signal, Sidemarker and Daytime
Running Lamps........................................5-66
Halogen Bulbs............................................5-64
Pickup Box Identi®cation and Fender Marker
Lamps....................................................5-70
Roof Marker Lamps.....................................5-67
Headphones.................................................3-122
Heated Seats................................................... 1-6
Heating.........................................................3-31
Heavy-DutyTrailer Wiring Harness Package........4-96
Highway Hypnosis...........................................4-44
Hill and Mountain Roads..................................4-45
Hitches..........................................................4-88
Hood
Checking Things Under................................5-10
Release.....................................................5-10
Horn............................................................... 3-7
How to Add Coolant to the Coolant Surge Tank
for Gasoline Engines....................................5-41
How to Add Fluid............................5-27, 5-30, 5-32
How to Check........................5-25, 5-28, 5-31, 5-85
How to Check and Add Fluid............................5-33
How to Check Lubricant...................................5-59
How to Check Power Steering Fluid..................5-46
How to Inspect...............................................5-23
How to Use This Manual...................................... iiHow to Wear Safety Belts Properly...................1-16
Hydraulic Clutch.............................................5-32
Hydroplaning..................................................4-40
I
If No Steam Is Coming From Your Engine..........5-38
If Steam Is Coming From Your Engine...............5-37
If the Light is Flashing.....................................3-50
If the Light Is On Steady.................................3-50
If You Are Caught in a Blizzard.........................4-49
If You Are Stuck in Sand, Mud, Ice or Snow.......4-51
If You Do Decide To Pull A Trailer.....................4-71
Ignition Positions.............................................2-22
Infants and Young Children, Restraints...............1-35
In¯ation - Tire Pressure...................................5-84
Instrument Panel
Cluster.......................................................3-34
Overview..................................................... 3-4
Instrument Panel Brightness Control..................3-19
Instrument Panel Fuse Block..........................5-126
Interior Lamps................................................3-19
J
Jump Starting.................................................5-53
8