Page 431 of 484
*1— Gasoline Engine and Fuel Injection Rail #2.
*2— Gasoline Engine and Fuel Injection Rail #1.
*3— Gasoline Engine; Oxygen Sensors.
*4— Gasoline Engine; Oxygen Sensors.
*5— Ignition 1
*6— Powertrain Control Module, Fuel Pump.
*7— Rear Climate Control.
*8— Sunroof.
Fuses Usage
GLOW PLUG Not Used
CUST FEED Accessory Power
HYBRID Not Used
STUD #1 Auxiliary Power
MBECMid-Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLWR Front Climate Control Fan
Fuses Usage
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/ECASAutomatic Level Control
(ALC) Compressor
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
5-115
Page 432 of 484

Fuses Usage
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 PWRAccessory Power
Outlet — Console
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
RTDElectronic Suspension
Control, Automatic Level
Control (ALC) Exhaust
TRL B/U Backup Lamps Trailer WiringFuses Usage
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-LTDriver’s Side High Beam
Headlamp
LH HIDLeft Hand High Intensity
Discharge Lamps
DRL Daytime Running Lamps
5-116
Page 446 of 484

At Least Once a Year
Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brake. SeeParking Brake on page 2-33.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. Try to start the engine in each gear. The vehicle
should start only in PARK (P) or NEUTRAL (N).
If the vehicle starts in any other position, contact
your GM Goodwrench
®dealer for service.
Automatic Transmission Shift Lock
Control System Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle. It should be parked on a level
surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-33.
Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the ignition to RUN, but do
not start the engine. Without applying the regular
brake, try to move the shift lever out of PARK (P)
with normal effort. If the shift lever moves out
of PARK (P), contact your GM Goodwrench
®dealer
for service.
6-10
Page 447 of 484

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition to LOCK in each shift lever position.
The ignition 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.
6-11
Page 477 of 484

Headlamps (cont.)
Halogen Bulbs............................................5-52
High Intensity Discharge (HID) Lighting...........5-52
High/Low Beam Changer................................ 3-8
On Reminder..............................................3-15
Heated Seats................................................... 1-4
Heater...........................................................3-22
Highbeam On Light.........................................3-43
Highway Hypnosis...........................................4-35
Hill and Mountain Roads..................................4-36
Hood
Checking Things Under................................5-10
Release.....................................................5-11
Horn............................................................... 3-6
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-14
I
Ignition Positions.............................................2-26
Infants and Young Children, Restraints...............1-30
In ation -- Tire Pressure..................................5-66
Instrument Panel
Overview..................................................... 3-4
Storage Area..............................................2-53
Instrument Panel (I/P)
Brightness..................................................3-17
Cluster.......................................................3-29
J
Jump Starting.................................................5-40
K
Keyless Entry System....................................... 2-4
Keys............................................................... 2-3
L
Labeling, Tire Sidewall.....................................5-61
Lamps
Battery Run-Down Protection.........................3-18
Dome........................................................3-17
Dome Lamp Override...................................3-18
Exterior......................................................3-14
Exterior Cargo.............................................3-17
Fog ...........................................................3-16
Reading.....................................................3-18
LATCH System
Child Restraints...........................................1-39
Light
Airbag Readiness........................................3-31
Anti-Lock Brake System Warning...................3-36
Brake System Warning.................................3-35
Cargo Lamp...............................................3-43
7