Page 325 of 452

Notice:Ignoring these steps could result in
costly damage to your vehicle that would
not be covered by your warranty.
Trying to start your vehicle by pushing or
pulling it will not work, and it could damage
your vehicle.
1. Check the other vehicle. It must have a
12-volt battery with a negative ground system.
Notice:If the other vehicle’s system is not a
12-volt system with a negative ground,
both vehicles can be damaged. Only use
vehicles with 12-volt systems with negative
grounds to jump start your vehicle.
2. Get the vehicles close enough so the jumper
cables can reach, but be sure the vehicles are
not touching each other. If they are, it could
cause a ground connection you do not
want. You would not be able to start your
vehicle, and the bad grounding could damage
the electrical systems.To avoid the possibility of the vehicles rolling,
set the parking brake firmly on both vehicles
involved in the jump start procedure. Put
an automatic transmission in PARK (P) or a
manual transmission in NEUTRAL before
setting the parking brake.
Notice:If you leave your radio or other
accessories on during the jump starting
procedure, they could be damaged. The repairs
would not be covered by your warranty.
Always turn off your radio and other
accessories when jump starting your vehicle.
3. Turn off the ignition on both vehicles.
Unplug unnecessary accessories plugged into
the cigarette lighter or the accessory power
outlet. Turn off the radio and all lamps that are
not needed. This will avoid sparks and help
save both batteries. And it could save
the radio!
325
Page 390 of 452
Engine Compartment Fuse Block
The fuse block is located in the engine
compartment on the driver’s side of the vehicle.
Fuse Usage
1 Radio Battery
2Powertrain Control Module Battery
(Gas), FOH, Engine Control Module,
Transmission Control Module
Battery (Diesel)
Fuse Usage
3 Left Rear Turn Lamp
4 Right Rear Turn Lamp
5 Back-up Lamps Trailer Wiring
6 Ignition 0
7 Stoplamp
8 Rear Defogger/Heated Mirror
9Right Daytime Running Lamp/
Turn Signal
10Left Daytime Running Lamp/
Turn Signal
11 Truck Body Control Module 4
12 Fuel Pump
13 Trailer
14 Hazard Flashers
15 Horn
16 Truck Body Control Module 3
17 Trailer Stop/Turn Signal
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Fuse Usage
18 Truck Body Control Module 2
19 Truck Body Control Module
20 Remote Function Actuator
21 Engine 2 (Gas), Spare (Diesel)
22 Ignition E
23 Engine 1
24Truck Body Control Module
Ignition 1
25 Spare (Gas), Fuel Heater (Diesel)
26 Inside Rearview Mirror
27 Crankcase
28Brake Transmission Shift
Interlock System
29 Auxiliary Power Outlets
30 Cigarette Lighter
31 Instrument Panel Cluster
32 Air ConditioningFuse Usage
33Spare (Gas), Engine Control
Module (Diesel)
34Canister Vent Solenoid (Gas), Rear
Fog Lamps (Diesel)
35Spare (Gas & LLY Diesel), Fan
Clutch (LMM Diesel)
36Brake Transmission Shift Interlock,
Vehicle Back-Up
37 Airbag
38Powertrain Control Module Ignition 1
(Gas), Engine Control Module,
Transmission Control Module, Glow
Plug Control Module Ignition 1
(Diesel)
39Oxygen Sensor B (Gas),
Spare (Diesel)
40Oxygen Sensor A (Gas),
Spare (Diesel)
41 Windshield Wipers
42 Right Headlamp - Low Beam
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Fuse Usage
43 Left Headlamp - Low Beam
44 Left Headlamp - High Beam
45 Right Headlamp - High Beam
46Truck Body Controller- Accessory
(Gas), Truck Body Controller,
Transmission Control Module
Accessory (Diesel)
47 Front Windshield Wiper
48Anti-lock Brakes, Vehicle Stability
Enhancement System
49 Ignition A
50 Trailer
51 Climate Control Blower
52 Ignition B
63Spare (Gas), Engine Control Module
Actuator (Diesel)
64 SpareRelays Usage
53 Windshield Wiper
54 Air Conditioning
55Spare (Gas), Rear Fog Lamps
(Diesel)
56 Headlamp - High Beam
57 Fuel Pump
58 Headlamp - Low Beam
59 Horn
SPARE (G),
ECM (D)Spare (Gas), Engine Control
Module (Diesel)
STRTR Starter
Circuit Breaker Usage
PWR SEAT Power Seat
392
Page 407 of 452

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 128.
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 128.
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.
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Page 408 of 452

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 ignition 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 flush any
corrosive materials from the underbody. Take
care to clean thoroughly any areas where mud and
other debris can collect.
408
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Headlamps.................................................. 334
Bulb Replacement.................................... 334
Daytime Running Lamps.......................... 156
Flash-to-Pass........................................... 149
Front Turn Signal, Sidemarker and
Parking Lamps..................................... 336
Halogen Bulbs......................................... 334
High/Low Beam Changer......................... 149
On Reminder........................................... 155
Heater......................................................... 159
Highbeam On Light..................................... 185
Highway Hypnosis....................................... 251
Hill and Mountain Roads............................. 252
Hood
Checking Things Under............................ 294
Release................................................... 295
Horn............................................................ 146
How to Use This Manual................................ 4
How to Wear Safety Belts Properly............... 22
I
Ignition Positions......................................... 121
Infants and Young Children, Restraints.......... 44
Inflation - Tire Pressure............................... 348Instrument Panel
Overview.................................................. 144
Instrument Panel (I/P)
Brightness................................................ 156
Cluster..................................................... 167
J
Jump Starting.............................................. 324
K
Keyless Entry System................................. 104
Keys........................................................... 102
L
Labeling, Tire Sidewall................................. 341
Lamps
Battery Run-Down Protection................... 158
Dome....................................................... 156
Dome Lamp Override............................... 157
Exterior.................................................... 154
Reading................................................... 157
445