2006 GMC SIERRA trailer

If you get the ENGINE COOLANT HOT message with
no sign of steam, try this for a minute or so:
1. If your air conditioner is on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
3. If you are in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving — DRIVE (D) or THIRD (3).
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.
If the warning continues, pull over, stop, park, and fast
idle your vehicle right away.
If there is still no sign of steam and your vehicle is
equipped with an engine-driven cooling fan, push down
the accelerator until the engine speed is about twice as
fast as normal idle speed for at least three minutes while
you are parked.
If there is still no sign of steam and your vehicle is
equipped with an electric engine cooling fan, idle the
engine for three minutes while you are parked.
If you still have the warning, turn off the engine and get
everyone out of the vehicle until it cools down. Also,
see “Overheated Engine Protection Operating Mode”
later in this section.
You may decide not to lift the hood but to get service
help right away.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 (Gasoline Engine) on
page 5-20.
5-39

Engine Fan Noise
If your vehicle is equipped with 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 cooling system
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.
If your vehicle is equipped with electric cooling fans,
you may hear the fans spinning at low speed during most
everyday driving. The fans may turn off if no cooling is
required. Under heavy vehicle loading, trailer towing,
and/or high outside temperatures, or if you are operating
your air conditioning system, the fans change to high
speed and you may hear an increase in fan noise.
This is normal and indicates that the cooling system is
functioning properly. The fans will change to low speed
when additional cooling is no longer required.
Power Steering Fluid
SeeEngine Compartment
Overview on page 5-14for
reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power steering uid
unless you suspect there is a leak in the system or you
hear an unusual noise. A uid loss in this system could
indicate a problem. Have the system inspected and
repaired.
5-45

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
LT DRDriver’s Door Harness
Connection
CRUISECruise Control, Power Take
Off (PTO)
UNLCK (Relay)Power Door Lock Relay
(Unlock Function)
RR FOG LP Not Used
BRAKE Anti-Lock Brake SystemFuses Usage
DRIVER UNLCKPower 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 Trailer
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
5-125

Fuses Usage
BODY Harness Connector
DDM Driver Door Module
AUX PWR 2, M/GATE Not Used
LCKS Power Door Lock System
ECC, TPMTire Pressure Monitoring
System
TBC 2C Truck Body Controller
HAZRD Flasher Module
CB LT DRSLeft Power Windows
Circuit Breaker
TBC 2B Truck Body Controller
TBC 2A Truck Body ControllerCenter 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)
5-126

*1Fuel Injection Rail #2-Gasoline Engine; Engine
Control Module-Diesel Engine.
*2Fuel Injection Rail #1-Gasoline Engine;
Actuator-Diesel Engine.
*3Oxygen Sensors-Gasoline Engine; Fuel Heater-Diesel
Engine.
*4Oxygen Sensors-Gasoline Engine; Engine Control
Module 1-Diesel Engine.
*5Ignition 1-Gasoline Engine; Engine Control
Module-Diesel Engine.
*6Powertrain Control Module B-Gasoline Engine;
Engine Control Module B-Diesel Engine.
*7Rear Climate Control.
*8Sunroof.
Fuses Usage
GLOW PLUGDiesel Glow Plugs and
Intake Air Heater
CUST FEED Gasoline Accessory Power
HYBRID Hybrid
STUD #1Auxiliary Power (Single
Battery and Diesels Only)/
Dual Battery (TP2) Do not
install fuse.
Fuses Usage
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
STUD #2*Accessory 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
5-129

Fuses Usage
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
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake
Controller-Gasoline Engine,
Fan Clutch-Diesel Engines
IGN EInstrument Panel Cluster,
Air Conditioning Relay,
Turn Signal/Hazard Switch,
Starter RelayFuses Usage
RTD Ride Control
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 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
5-130

(f)Lubricate all key lock cylinders, body door hinges,
hood latch assembly, secondary latch, pivots, spring
anchor, release pawl, tailgate hinges, tailgate linkage,
tailgate handle pivot points, latch bolt, fuel door hinge,
locks, and folding seat hardware. More frequent
lubrication may be required when exposed to a corrosive
environment. Applying silicone grease on weatherstrips
with a clean cloth will make them last longer, seal better
and not stick or squeak.
(g)Check vent hose at transfer case for kinks and
proper installation.
(h)Change automatic transmission uid and lter if the
vehicle Gross Vehicle Weight Rating (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. This service can
be complex; you should have your dealer perform this
service. See Engine Coolant on page 5-35 for 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.
(n)Vehicles with diesel engine or with GVWR above
10,000 lbs (4 536 kg) only: Inspect shields for damage or
looseness. Adjust or replace as required. This is a Noise
Emission Control Service. Applicable to vehicles sold in
the United States and recommended for vehicles sold in
Canada.
6-10

Aluminum or Chrome-Plated Wheels,
Cleaning...............................................5-118
Buying New Tires........................................5-84
Chains.......................................................5-89
Changing a Flat Tire....................................5-91
Cleaning...................................................5-119
Different Size..............................................5-85
Dual Tire Operation.....................................5-80
If a Tire Goes Flat.......................................5-90
Ination -- Tire Pressure...............................5-79
Inspection and Rotation................................5-81
Installing the Spare Tire................................5-96
Removing the Flat Tire.................................5-96
Removing the Spare Tire and Tools...............5-92
Secondary Latch System............................5-105
Spare Tire................................................5-112
Storing a Flat or Spare Tire and Tools..........5-108
Tire Sidewall Labeling..................................5-73
Tire Terminology and Denitions....................5-76
Uniform Tire Quality Grading.........................5-86
Wheel Alignment and Tire Balance.................5-87
Wheel Replacement.....................................5-87
When It Is Time for New Tires......................5-83
Tonneau Cover...............................................2-80
Tow/Haul Mode...............................................2-31
Tow/Haul Mode Light.......................................3-50
Towing
Power Take-Off (PTO)..................................4-97
Recreational Vehicle.....................................4-62Towing (cont.)
Towing a Trailer..........................................4-67
Your Vehicle...............................................4-62
Traction
Assist System (TAS)...................................... 4-8
Manual Selectable Ride................................4-10
Off Light.....................................................3-43
Trailer
Recommendations.......................................4-96
Transmission
Fluid, Automatic..................................5-28, 5-30
Fluid, Manual..............................................5-33
Temperature Gage.......................................3-44
Up-Shift Light..............................................3-41
Transmission Operation, Automatic....................2-26
Transmission Operation, Manual........................2-34
Trip Odometer................................................3-33
Truck-Camper Loading Information....................4-59
Turn and Lane-Change Signals.......................... 3-7
Turn Signal/Multifunction Lever........................... 3-7
U
Understanding Radio Reception.......................3-130
Uniform Tire Quality Grading............................5-86
Universal Home Remote System.......................2-75
Operation...................................................2-76
Up-Shift Light.................................................3-41
13