2006 GMC SIERRA cooling

OIL PRESSURE LOW
Notice:If you drive your vehicle while the engine oil
pressure is low, severe engine damage may occur.
If a low oil pressure warning appears on the Driver
Information Center (DIC), stop the vehicle as soon as
possible. Do not drive the vehicle until the cause of
the low oil pressure is corrected. SeeEngine Oil
(Gasoline Engine) on page 5-20for more information.
If low oil pressure levels occur, this message will be
displayed on the DIC and a chime will sound. Stop the
vehicle as soon as safely possible and do not operate it
until the cause of the low oil pressure has been corrected.
Check your oil as soon as possible and have your vehicle
serviced by your GM dealer. SeeEngine Oil (Gasoline
Engine) on page 5-20.
PASSENGER DOOR AJAR
If the passenger’s door is not fully closed, this message
will appear on the display and you will hear a chime. Stop
and turn off the vehicle, check the door for obstacles and
close the door again. Check to see if the message still
appears on the DIC. Pressing any of the four DIC buttons
will acknowledge the message and clear it from the DIC
display. If your vehicle does not have the four DIC
buttons, pressing the trip odometer reset stem will
acknowledge the message and clear it from the
DIC display.
RANGE SHIFT INHIBITED
(Allison Transmission®Only)
If the transmission is unable to shift into a selected gear,
this message will appear on the DIC. The electronic shift
position indicator on the instrument panel cluster may
blink when this occurs. To make the vehicle shift to the
requested gear, you may have to shift back to PARK (P)
or NEUTRAL (N) and re-select the desired gear.
REDUCED ENGINE POWER
This message is displayed when the cooling system
temperature gets too hot and the engine further enters
the engine coolant protection mode.
SeeEngine Overheating on page 5-37for additional
information.
RIGHT REAR DOOR AJAR (Crew Cab)
If the passenger’s side rear door is not fully closed, this
message will appear on the display and you will hear a
chime. Stop and turn off the vehicle, check the door for
obstacles and close the door again. Check to see if the
message still appears on the DIC. Pressing any of the
four DIC buttons will acknowledge the message and clear
it from the DIC display. If your vehicle does not have the
four DIC buttons, pressing the trip odometer reset stem
will acknowledge the message and clear it from the
DIC display.
3-60

After Off-Road Driving
Remove any brush or debris that has collected on
the underbody, chassis, or under the hood. These
accumulations can be a re hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires, and exhaust system
for damage. Also, check the fuel lines and cooling system
for any leakage.
Your vehicle will require more frequent service due to
off-road use. Refer to the Maintenance Schedule for
additional information.
Driving at Night
Night driving is more dangerous than day driving. One
reason is that some drivers are likely to be impaired — by
alcohol or drugs, with night vision problems, or by fatigue.
Here are some tips on night driving.
Drive defensively.
Do not drink and drive.
Adjust the inside rearview mirror to reduce the glare
from headlamps behind you.
Since you cannot see as well, you may need to
slow down and keep more space between you
and other vehicles.
Slow down, especially on higher speed roads. Your
vehicle’s headlamps can light up only so much road
ahead.
In remote areas, watch for animals.
If you are tired, pull off the road in a safe place
and rest.
No one can see as well at night as in the daytime. But as
we get older these differences increase. A 50-year-old
driver may require at least twice as much light to see the
same thing at night as a 20-year-old.
4-32

Hill and Mountain Roads
Driving on steep hills or mountains is different from
driving in at or rolling terrain.If you drive regularly in steep country, or if you are
planning to visit there, here are some tips that can
make your trips safer and more enjoyable. See
Off-Road Driving on page 4-16for information about
driving off-road.
Keep your vehicle in good shape. Check all uid
levels and also the brakes, tires, cooling system,
and transmission. These parts can work hard on
mountain roads.
{CAUTION:
If you do not shift down, your brakes could get
so hot that they would not work well. You would
then have poor braking or even none going
down a hill. You could crash. Shift down to let
your engine assist your brakes on a steep
downhill slope.
4-40

Trailer Brakes
If your trailer weighs more than 2,000 lbs (900 kg)
loaded, then it needs its own brakes – and they must be
adequate. Be sure to read and follow the instructions for
the trailer brakes so you’ll be able to install, adjust and
maintain them properly.
Your trailer brake system can tap into the vehicle’s
hydraulic brake system only if:
The trailer parts can withstand
3,000 psi (20 650 kPa) of pressure.
The trailer’s brake system will use less than
0.02 cubic inch (0.3 cc) of uid from your vehicle’s
master cylinder. Otherwise, both braking systems
won’t work well. You could even lose your brakes.
If everything checks out this far, make the brake tap at
the port on the master cylinder that sends the uid to the
rear brakes. But don’t use copper tubing for this. If you
do, it will bend and nally break off. Use steel brake
tubing.
Driving with a Trailer
{CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon monoxide
(CO) could come into your vehicle. You cannot
see or smell CO. It can cause unconsciousness
or death. SeeEngine Exhaust on page 2-57.To
maximize your safety when towing a trailer:
Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main heating
or cooling system on and with the fan on
any speed. This will bring fresh, outside air
into your vehicle. Do not use the climate
control setting for maximum air because it
only recirculates the air inside your vehicle.
SeeClimate Control System on page 3-21.
4-88

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
Start your engine
Shift into a gear
Release the parking brake
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. SeeScheduled Maintenance (Gasoline
Engine) on page 6-4for more information. Things that
are especially important in trailer operation are automatic
transmission uid (don’t overll), engine oil, axle
lubricant, belt, cooling system and brake system. Each of
these is covered in this manual, and the Index will help
you nd them quickly. If you’re trailering, it’s a good idea
to review these sections before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
Your vehicle is equipped with one of the following wiring
harnesses for towing a trailer or hauling a slide-in
camper.
Basic Trailer Wiring
All regular, extended cab and crew cab pickups have an
eight-wire trailer towing harness.
For vehicles not equipped with heavy duty trailering, the
harness is clipped to the vehicle’s frame behind the spare
tire mount. The harness requires the installation of a
trailer connector, which is available through your dealer.
4-92

Service............................................................5-4
Accessories and Modications..........................5-4
California Proposition 65 Warning.....................5-4
Doing Your Own Service Work.........................5-5
Adding Equipment to the Outside of
Your Vehicle..............................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-6
Gasoline Specications....................................5-6
California Fuel...............................................5-7
Additives.......................................................5-7
Fuel E85 (85% Ethanol)..................................5-8
Fuels in Foreign Countries...............................5-9
Filling the Tank............................................5-10
Filling a Portable Fuel Container.....................5-11
Checking Things Under the Hood....................5-12
Hood Release..............................................5-13
Engine Compartment Overview.......................5-14
Engine Oil (Gasoline Engine)..........................5-20
Engine Oil Life System (Gasoline Engine)........5-23
Engine Air Cleaner/Filter (Gasoline Engines).......5-25
Automatic Transmission Fluid
(Except Allison Transmission
®) ....................5-28Automatic Transmission Fluid
(Allison Transmission
®) ...............................5-30
Manual Transmission Fluid.............................5-33
Hydraulic Clutch...........................................5-34
Engine Coolant.............................................5-35
Coolant Surge Tank Pressure Cap..................5-37
Engine Overheating.......................................5-37
Overheated Engine Protection Operating Mode
(V8 Engines Only)......................................5-39
Cooling System............................................5-40
Engine Fan Noise.........................................5-45
Power Steering Fluid.....................................5-45
Windshield Washer Fluid................................5-46
Brakes........................................................5-47
Battery........................................................5-51
Jump Starting...............................................5-52
Rear Axle.......................................................5-58
Four-Wheel Drive............................................5-59
Front Axle......................................................5-60
Noise Control System.....................................5-62
Tampering with Noise Control System
Prohibited.................................................5-62
Section 5 Service and Appearance Care
5-1

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter (Gasoline Engines) on page 5-25.
B. Coolant Surge Tank and Pressure Cap. SeeEngine
Coolant on page 5-35andCoolant Surge Tank
Pressure Cap on page 5-37.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter (Gasoline Engines) on
page 5-25.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-20.
E. Automatic Transmission Fluid Dipstick (If Equipped).
See “Checking the Fluid Level” underAutomatic
Transmission Fluid (Except Allison Transmission
®)
on page 5-28orAutomatic Transmission Fluid
(Allison Transmission
®) on page 5-30.
F. Engine Cooling Fan. SeeCooling System on
page 5-40.
G. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-20.H. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-45.
I. Remote Negative (−) Terminal (GND). SeeJump
Starting on page 5-52.
J. Remote Positive (+) Terminal. SeeJump Starting on
page 5-52.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 5-47.
L. Clutch Fluid Reservoir (If Equipped). SeeHydraulic
Clutch on page 5-34.
M. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-127.
N. Battery. SeeBattery on page 5-51.
O. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-46.
5-15

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter (Gasoline Engines) on page 5-25.
B. Coolant Surge Tank and Pressure Cap. SeeEngine
Coolant on page 5-35andCoolant Surge Tank
Pressure Cap on page 5-37.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter (Gasoline Engines)
on page 5-25.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-20.
E. Automatic Transmission Fluid Dipstick (If Equipped).
See “Checking the Fluid Level” underAutomatic
Transmission Fluid (Except Allison Transmission
®)
on page 5-28orAutomatic Transmission Fluid
(Allison Transmission
®) on page 5-30.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-20.
G. Engine Cooling Fan. SeeCooling System on
page 5-40.H. Remote Negative (−) Terminal (GND). SeeJump
Starting on page 5-52.
I. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-45.
J. Remote Positive (+) Terminal. SeeJump Starting on
page 5-52.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 5-47.
L. Clutch Fluid Reservoir (If Equipped). SeeHydraulic
Clutch on page 5-34.
M. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-127.
N. Battery. SeeBattery on page 5-51.
O. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-46.
5-17