Page 116 of 540

B (ACCESSORY):This position lets you use things
like the radio and the windshield wipers when the
engine is off.
Notice:Lengthy operation of features such as
the radio in the accessory ignition position may
drain the battery and prevent your vehicle from
starting. Do not operate your vehicle in the
accessory ignition position for a long period
of time.
C (RUN):This is the position for driving.
D (START):This position starts the engine.
Retained Accessory Power (RAP)
Your vehicle may be equipped with a Retained
Accessory Power (RAP) feature which will allow certain
features on your vehicle to continue to work up to
10 minutes after the ignition key is turned to LOCK.
Your radio, power windows, sunroof (if equipped),
and OnStar
®System (if equipped) will work when the
ignition key is in RUN or ACCESSORY. Once the key is
turned from RUN to LOCK, these features will continue
to work for up to 10 minutes or until a door is opened.
Starting the Engine
Your vehicle is equipped with Starter Motor Control.
This feature assists in starting the engine and protects
the electrical system. This feature may cause the
engine to crank even after the ignition key is not
in START.
Move your shift lever to PARK (P) or NEUTRAL (N).
Your engine will not start in any other position — that
is a safety feature. To restart when you are already
moving, use NEUTRAL (N) only.
Notice:Do not try to shift to PARK (P) if your
vehicle is moving. If you do, you could damage
the transmission. Shift to PARK (P) only when your
vehicle is stopped.
1. With your foot off the accelerator pedal, turn the
ignition key to START. When the engine starts,
let go of the key. The idle speed will go down
as your engine gets warm.
Notice:Holding your key in START for longer
than 15 seconds at a time will disengage the starter
motor, cause your battery to be drained much
sooner, and add excessive heat that can damage
your starter motor. Try not to hold the key in
START for longer than 15 seconds and wait
about 15 seconds between each try to help avoid
draining your battery or damaging your starter.
2-20
Page 485 of 540

*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 Gasoline Accessory Power
HYBRID Not Used
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
BLWR Front Climate Control Fan
LBECLeft Bussed Electrical
Center, Door Modules,
Door Locks, Auxiliary Power
Outlet — Rear Cargo Area
and Instrument Panel
Fuses Usage
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
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
5-111
Page 486 of 540

Fuses Usage
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 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 RelayFuses Usage
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LTDriver’s Side High Beam
Headlamp
LH HID Not Used
DRL Daytime Running Lamps
RVC Regulated Voltage Control
IPC/DICInstrument Panel Cluster/
Driver Information Center
HVAC/ECAS Climate Control Controller
CIG LTR Cigarette Lighter
HI HDLP-RTPassenger’s Side High Beam
Headlamp
HDLP-LOW Headlamp Low Beam Relay
A/C COMPAir Conditioning Compressor
Relay
A/C COMP Air Conditioning Compressor
TCMB Transmission Control Module
RR WPR Rear Wiper/Washer
RADIO Audio System
SEO B1Mid Bussed Electrical Center,
Universal Home Remote
System, Rear Heated Seats
LO HDLP-LTDriver’s Side Headlamp
Low Beam
5-112
Page 501 of 540

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 2-31.
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 2-31.
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.
6-11