towing GMC SIERRA CLASSIC 2007 Service Manual

If No Steam Is Coming From Your
Engine
The ENGINE COOLANT HOT message, along
with a low coolant condition, can indicate a serious
problem.
If you get an engine overheat warning, 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. SeeTowing a Trailer on
page 429.
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.
507

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 486.
Cooling System
When you decide it is safe to lift the hood, here is
what you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan
8.1L V8 Engines
508

Engine Fan Noise
If 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 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 has 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 may 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.
514

(e)Make sure the safety belt reminder light and all
your belts, buckles, latch plates, retractors, and
anchorages are working properly. Look for
any other loose or damaged safety belt system
parts. If you see anything that might keep a safety
belt system from doing its job, have it repaired.
Have any torn or frayed safety belts replaced. Also
look for any opened or broken airbag coverings,
and have them repaired or replaced. The
airbag system does not need regular maintenance.
(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 502 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.
624

(k)Inspect system. Check all fuel and vapor lines
and hoses for proper hook-up, routing, and
condition. Check that the purge valve, if the vehicle
has one, works properly.
(m)Change automatic transmission uid and
external transmission 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.
(p)If you drive regularly under dusty conditions,
inspect the lter or change indicator (if equipped)
at each engine oil change.(q)Visually inspect belt for fraying, excessive
cracks, or obvious damage. Replace belt if
necessary.
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 629.
At the First 100, 1,000 and 6,000
Miles (160, 1 600 and 10 000 km)
Check dual wheel nut torque. For proper torque,
seeCapacities and Specications on page 609.
625

GMC and General Motors of Canada Limited
reserve the right to limit services or reimbursement
to an owner or driver when, in their sole
discretion, the claims become excessive in
frequency or type of occurrence.
Roadside Assistance is not part of or included in
the coverage provided by the New Vehicle Limited
Warranty. GMC and General Motors of Canada
reserve the right to make any changes or
discontinue the Roadside Assistance program at
any time without notication.
Towing and Road Service Exclusions
Specically excluded from Roadside Assistance
coverage are towing or services for vehicles
operated on a non-public roadway or highway,
nes, impound towing caused by a violation
of local, Municipal, State, Provincial, or Federal
law, and mounting, dismounting or changing
of snow tires, chains, or other traction devices.
Courtesy Transportation
To enhance your ownership experience, we and
our participating dealers are proud to offer
Courtesy Transportation, a customer support
program for new vehicles.
For warranty repairs during the Bumper-to-Bumper
(U.S.) or Base Warranty Coverage period
(Canada), provided by the New Vehicle Limited
Warranty, interim transportation may be available
under the Courtesy Transportation program.
Several courtesy transportation options are
available to assist in reducing your inconvenience
when warranty repairs are required.
Courtesy Transportation is not a part of the New
Vehicle Limited Warranty and is available only
at participating dealers. A separate booklet entitled
“Warranty and Owner Assistance Information”
furnished with each new vehicle provides detailed
warranty coverage information.
647

If your vehicle is leased, the leasing company
may require you to have insurance that assures
repairs with Genuine GM Original Equipment
Manufacturer (OEM) parts or Genuine
Manufacturer replacement parts. Read your lease
carefully, as you may be charged at the end of
your lease for poor quality repairs.
If an Accident Occurs
Here is what to do if you are involved in an
accident.
Try to relax and then check to make sure you
are all right. If you are uninjured, make sure
that no one else in your vehicle, or the
other vehicle, is injured.
If there has been an injury, call 911 for help.
Do not leave the scene of an accident until
all matters have been taken care of. Move
your vehicle only if its position puts you
in danger or you are instructed to move it by a
police officer.
Give only the necessary and requested
information to police and other parties involved
in the accident. Do not discuss your personal
condition, mental frame of mind, or anything
unrelated to the accident. This will help guard
against post-accident legal action.
If you need roadside assistance, call
GM Roadside Assistance. SeeRoadside
Assistance Program on page 644for more
information.
If your vehicle cannot be driven, know where
the towing service will be taking it. Get a
card from the tow truck operator or write down
the driver’s name, the service’s name, and
the phone number.
Remove any valuables from your vehicle before
it is towed away. Make sure this includes your
insurance information and registration if you
keep these items in your vehicle.
653

Rear Axle.................................................... 527
Locking.................................................... 366
Rear Door Security Locks........................... 126
Rear Doors................................................. 126
Rear Safety Belt Comfort Guides.................. 41
Rear Seat Audio (RSA)............................... 347
Rear Seat Entertainment System................. 334
Rear Seat Operation.............................. 19, 20
Rear Seat Passengers, Safety Belts.............. 38
Rearview Mirror, Automatic Dimming with
Compass and Temperature Display.......... 180
Rearview Mirror, Automatic Dimming with
OnStar
®, Compass and Temperature
Display..................................................... 176
Rearview Mirrors......................................... 176
Reclining Seatbacks...................................... 15
Recommended Fluids and Lubricants.......... 629
Recovery Hooks.......................................... 408
Recreational Vehicle Towing........................ 424
Remote Keyless Entry System.................... 116
Remote Keyless Entry System, Operation ... 117
Removing the Flat Tire and Installing the
Spare Tire................................................ 571
Removing the Spare Tire and Tools............ 566
Replacement Bulbs..................................... 541Reporting Safety Defects
Canadian Government............................. 656
General Motors........................................ 656
United States Government....................... 656
Restraint System Check
Checking the Restraint Systems............... 111
Replacing Restraint System Parts
After a Crash........................................ 112
Retained Accessory Power (RAP)................ 137
Right Front Passenger Position,
Safety Belts............................................... 37
Roadside
Assistance Program................................. 644
Rocking Your Vehicle to Get it Out.............. 407
Routing, Engine Drive Belt.......................... 633
Running the Engine While Parked............... 175
S
Safety Belt
Reminder Light........................................ 247
Safety Belts
Care of.................................................... 592
Center Front Passenger Position................ 37
Driver Position........................................... 27
670

Tires (cont.)
Uniform Tire Quality Grading.................... 559
Wheel Alignment and Tire Balance........... 560
Wheel Replacement................................. 560
When It Is Time for New Tires................. 555
Tonneau Cover............................................ 203
Tow/Haul Mode........................................... 147
Tow/Haul Mode Light................................... 264
Towing
Power Take-Off (PTO).............................. 461
Recreational Vehicle................................. 424
Towing a Trailer....................................... 429
Your Vehicle............................................. 423
Traction
Assist System (TAS)................................ 363
Manual Selectable Ride........................... 365
Off Light.................................................. 256
Trailer
Recommendations.................................... 460
Transmission
Fluid, Automatic..............................494, 497
Fluid, Manual........................................... 500
Temperature Gage................................... 257
Up-Shift Light........................................... 254
Transmission Operation, Automatic.............. 140Transmission Operation, Manual.................. 149
Trip Odometer............................................. 246
Truck-Camper Loading Information.............. 421
Turn and Lane-Change Signals................... 214
Turn Signal/Multifunction Lever.................... 214
U
Understanding Radio Reception................... 350
Uniform Tire Quality Grading....................... 559
Universal Home Remote System........191, 192
Operation........................................193, 198
Up-Shift Light.............................................. 254
V
Vehicle
Control..................................................... 360
Damage Warnings....................................... 5
Loading.................................................... 409
Symbols...................................................... 5
Vehicle Customization, DIC......................... 282
Vehicle Data Collection and Event Data
Recorders................................................ 650
673