trailer CHEVROLET SILVERADO 2004 1.G Repair Manual

Coolant Surge Tank Pressure Cap
SeeEngine Compartment
Overview on page 5-14
for more information
on location.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank.
Notice:If the pressure cap is not tightly
installed, coolant loss and possible engine
damage may occur. Be sure the cap is properly
and tightly secured.
Engine Overheating
You will nd a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-46. In addition, you will
nd a ENGINE OVERHEATED and a REDUCED
ENGINE POWER message in the Driver Information
Center on the instrument panel. SeeDriver Information
Center (DIC) on page 3-53.
Overheated Engine Protection
Operating Mode (V8 Engines Only)
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates ring
groups of cylinders helps prevent engine damage. In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the oil
life system. SeeEngine Oil on page 5-20.
5-38

If No Steam Is Coming From
Your Engine
An overheat warning, along with a low coolant condition,
can indicate a serious problem. For more information,
seeDriver Information Center (DIC) on page 3-53.
If you get an engine overheat warning and don’t have a
low coolant condition, but see or hear no steam, the
problem may not be too serious. Sometimes the engine
can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high speed driving.
Idle for long periods in traffic.
Tow a trailer. See “Driving on Grades” under
Towing a Trailer on page 4-70.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If you have an air conditioner and it’s on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.3. If you’re in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving – AUTOMATIC OVERDRIVE
Xor
DRIVE (D) for automatic transmissions.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn’t come back on, you can
drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you’re parked. If you still have the warning,turn off the
engine and get everyone out of the vehicleuntil it
cools down. Also, see “Overheated Engine Protection
Operating Mode” listed previously in this section.
You may decide not to lift the hood but to get service
help right away.
5-40

6. Then replace the
pressure cap. Be sure
the pressure cap is
hand-tight and
fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the fan
speed increases as the clutch more fully engages.
So you may hear an increase in fan noise. This
is normal and should not be mistaken as the
transmission slipping or making extra shifts. It is
merely the coolingsystem functioning properly. The fan will slow
down when additional cooling is not required and the
clutch disengages.
You may also hear this fan noise when you start
the engine. It will go away as the fan clutch
partially disengages.
Power Steering Fluid
8100 V8 Engine
5-46

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
L DOORDriver’s Door Harness
Connection
CRUISECruise Control, Power Take
Off (PTO)
UNLOCK (Relay)Power Door Lock Relay
(Unlock Function)
RR FOG LP Not Used
BRAKE Anti-Lock Brake System
DRIVER UNLOCKPower 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 TrailerFuses Usage
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
BODY Harness Connector
DDM Driver Door Module
AUX PWR 2 Not Used
LOCKS Power Door Lock System
ECC Not Used
TBC 2C Truck Body Controller
FLASH Flasher Module
CB LT DOORSLeft Power Windows
Circuit Breaker
TBC 2B Truck Body Controller
TBC 2A Truck Body Controller
5-125

Center 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 Uptter (Not Used)
SL RIDERide Control
Harness Connection
HDLR 2 Headliner Wiring Connector
Device Usage
BODY Body Wiring Connector
DEFOG Rear Defogger Relay
HDLNR 1 Headliner Wiring Connector 1
SPARE RELAY Not Used
CB SEATDriver and Passenger Seat
Module Circuit Breaker
CB RT DOORRight Power Windows
Circuit Breaker
SPARE Not Used
INFOInfotainment
Harness Connection
5-126

*1— Gasoline Engine and Diesel Engine.
*2— Gasoline Engine; ECMRPV — Diesel Engine.
*3— Gasoline Engine; FUEL HT — Diesel Engine.
*4— Gasoline Engine; ECM I — Diesel Engine.
*5— 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
Outlet — Rear 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
SUNROOF Sunroof
SEO B2 Off-Road Lamps
5-129

Fuses Usage
4WSVent Solenoid
Canister/Quadrasteer
Module Power
RR HVAC Not Used
AUX PWRAuxiliary Power
Outlet — 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)
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control System
RR DEFOG Rear Window DefoggerFuses Usage
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
02B Oxygen Sensors
SIRSupplemental Inatable
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
HVAC/ECAS Climate Control Controller
CIG LTR Cigarette Lighter
HI HDLP-RT High Beam Headlamp-Right
HDLP-LOW Headlamp Low Beam Relay
A/C COMP Air Conditioning Compressor
5-130

(g)Add uid as needed. A uid loss could indicate a
problem; repair as needed. Check vent hose at transfer
case for kinks and proper installation.
(h)Change automatic transmission uid and lter if the
vehicle GVWR is over 8600 lbs. or if the vehicle is
mainly driven under one or more of these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or
delivery service.
(i)Drain, ush and rell cooling system. See Engine
Coolant on page 5-35for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap and ller neck.
Pressure test the cooling system and pressure cap.
(j)A uid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the uid level checked. Add uid if needed.
(k)Inspect system. Check all fuel and vapor lines and
hoses for proper hook-up, routing and condition.
Check that the purge valve works properly (if equipped).
Replace as needed.(l)Change clutch uid (or every 24 months, whichever
occurs rst).
(m)Change automatic transmission uid and lter if
the vehicle is mainly driven under one or more of
these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or
delivery service.
Owner Checks and Services
These owner checks and services should be performed
at the intervals specied to help ensure the safety,
dependability and emission control performance of your
vehicle. Your GM Goodwrench dealer can assist you
with these checks and services.
Be sure any necessary repairs are completed at once.
Whenever any uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
inRecommended Fluids and Lubricants on page 6-13.
6-9

D
Daytime Running Lamps..................................3-15
Defensive Driving............................................. 4-2
Defogging and Defrosting.........................3-23, 3-31
Delayed Locking.............................................2-10
Dinghy Towing................................................4-53
Doing Your Own Service Work........................... 5-4
Dolly Towing..................................................4-55
Dome Lamps.................................................3-18
Door
Delayed Locking..........................................2-10
Locks.......................................................... 2-8
Power Door Locks......................................... 2-9
Programmable Automatic Door Locks.............2-10
Rear Door Security Locks.............................2-13
Rear Doors.................................................2-14
Driver
Position, Safety Belt.....................................1-16
DRIVER DOOR AJAR.....................................3-66
Driver Information Center (DIC).........................3-53
DIC Operation and Displays..........................3-54
DIC Warnings and Messages........................3-64
Driving
At Night.....................................................4-36
City...........................................................4-40
Defensive..................................................... 4-2Driving (cont.)
Drunken....................................................... 4-2
Freeway.....................................................4-41
Hill and Mountain Roads..............................4-44
In Rain and on Wet Roads...........................4-37
Off-Road....................................................4-21
Winter........................................................4-46
Driving Across an Incline..................................4-32
Driving Downhill..............................................4-31
Driving in Mud, Sand, Snow or Ice....................4-34
Driving in Water..............................................4-34
Driving On Grades..........................................4-92
Driving on Off-Road Hills.................................4-27
Driving on Snow or Ice....................................4-46
Driving Through Deep Standing Water...............4-39
Driving Through Flowing Water.........................4-39
Driving Uphill..................................................4-28
Driving with a Trailer.......................................4-91
Dual Automatic Climate Control System.............3-25
Dual Climate Control System............................3-22
Dual Stage Air Bags........................................1-70
Dual Tire Operation.........................................5-83
DVD
Rear Seat Entertainment System..................3-114
DVD Distortion..............................................3-125
DVD Messages.............................................3-124
DVD Player..................................................3-117
5

E
Easy Exit Seat...............................................2-72
Electrical System
Add-On Equipment.....................................5-123
Fuses and Circuit Breakers.........................5-123
Power Windows and Other Power Options.......5-123
Windshield Wiper Fuses.............................5-123
Electronic Transfer Case..................................2-44
Emissions Inspection and Maintenance
Programs...................................................3-50
Engine
Air Cleaner/Filter.........................................5-25
Battery.......................................................5-52
Check and Service Engine Soon Light............3-48
Coolant......................................................5-35
Coolant Heater............................................2-26
Coolant Temperature Gage...........................3-46
Drive Belt Routing.......................................6-18
Engine Compartment Overview......................5-14
Exhaust.....................................................2-53
Fan Noise..................................................5-46
Oil .............................................................5-20
Overheating................................................5-38
Starting......................................................2-24
ENGINE COOLANT HOT.................................3-66
Engine Hour Meter Display...............................3-35
Engine Oil Additives........................................5-23
ENGINE OVERHEATED..................................3-66Entry Lighting.................................................3-18
Environmental Concerns..................................4-25
Event Data Recorders (EDR)............................. 7-9
Exit Lighting...................................................3-18
Express Down Windows..................................2-18
Extended Cab........................................1-56, 2-14
Extended Cab and Crew Cab...........................1-53
Extender, Safety Belt.......................................1-31
Exterior Lamps...............................................3-13
F
Fifth Wheel and Gooseneck Trailering................4-89
Filter
Engine Air Cleaner......................................5-25
Finding a Program Type (PTY) Station
(RDS and XM™).......................3-79, 3-90, 3-104
Finding a Station..................3-74, 3-77, 3-88, 3-102
Finish Care..................................................5-118
Finish Damage.............................................5-120
Five-Speed (VORTEC™ 4300 V6 and
4800 V8 Engines)........................................2-32
Five-Speed (VORTEC™ 6000 V8 Engine)...........2-31
Fixed Mast Antenna.......................................3-130
Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-92
Flat Tire, Changing.........................................5-93
6