2008 GMC SIERRA coolant temperature

ENGINE POWER IS REDUCED
This message displays and a chime sounds when the
cooling system temperature gets too hot and the engine
further enters the engine coolant protection mode.
SeeEngine Overheating on page 5-30for further
information.
This message also displays when the vehicle’s engine
power is reduced. Reduced engine power can affect the
vehicle’s ability to accelerate. If this message is on,
but there is no reduction in performance, proceed
to your destination. The performance may be reduced
the next time the vehicle is driven. The vehicle may
be driven at a reduced speed while this message is on,
but acceleration and speed may be reduced. Anytime
this message stays on, the vehicle should be taken
to your dealer/retailer for service as soon as possible.
FAST IDLE ON
If your vehicle has this feature, this message displays
when the fast idle feature is on. SeeFast Idle System on
page 2-25for more information.
FUEL LEVEL LOW
This message displays and a chime sounds if the fuel
level is low. Refuel as soon as possible. SeeFuel Gage
on page 3-53andFuel on page 5-6for more
information.
HOOD OPEN
This message displays and a chime sounds if the hood is
not fully closed. Stop and turn off the vehicle, check the
hood for obstructions, and close the hood again. Check to
see if the message still appears on the DIC.
LEFT REAR DOOR OPEN (Crew Cab)
This message displays and a chime sounds if the driver
side rear door is not fully closed and the vehicle is in
a drive gear. Stop and turn off the vehicle, check
the door for obstructions, and close the door again.
Check to see if the message still appears on the DIC.
OIL PRESSURE LOW STOP ENGINE
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 5-15for
more information.
This message displays if low oil pressure levels occur.
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 the oil as soon as possible
and have your vehicle serviced by your dealer/retailer.
SeeEngine Oil (Gasoline Engine) on page 5-15.
3-66

Turn Signals When Towing a Trailer
The arrows on your instrument panel will ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don’t shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.You can tow in DRIVE (D). You may want to shift the
transmission to lower gear selection if the transmission
shifts too often (e.g., under heavy loads and/or hilly
conditions).
You may also want to activate the tow/haul mode if the
transmission shifts too often. SeeTow/Haul Mode
Light on page 3-53.
When towing at high elevation on steep uphill grades,
consider the following: Engine coolant at higher
elevations will boil at a lower temperature than at or
near sea level. If you turn your engine off immediately
after towing at high elevation on steep uphill grades,
your vehicle may show signs similar to engine
overheating. To avoid this, let the engine run while
parked, preferably on level ground, with the transmission
in PARK (P) at least ve minutes before turning the
engine off. If you do get the overheat warning, see
Engine Overheating on page 5-30.
4-88

Engine Coolant
If your vehicle has the DURAMAX®Diesel engine, see
the DURAMAX®Diesel manual for more information.
The cooling system in your vehicle is lled with
DEX-COOL
®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-30.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL®coolant which will not damage
aluminum parts. If you use this coolant mixture, you do
not need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
CAUTION: (Continued)
5-28

Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixture at the surge tank, but only when the
engine is cool. SeeCooling System on page 5-34
for more information.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
Coolant Surge Tank Pressure Cap
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.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 5-14for more
information on location.
Engine Overheating
If your vehicle has the DURAMAX®Diesel engine, see
the DURAMAX®Diesel manual for more information.
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 ENGINE OVERHEATED STOP
ENGINE, ENGINE OVERHEATED IDLE ENGINE,
and ENGINE POWER IS REDUCED messages in the
Driver Information Center (DIC) on the instrument panel.
SeeDIC Warnings and Messages on page 3-63.
5-30

3. Fill the coolant surge tank with the proper mixture,
to the FULL COLD mark.4. With the coolant surge tank pressure cap off,
start the engine and let it run until the engine
coolant temperature gage indicates approximately
195°F (90°C).
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches the FULL COLD mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
6. Verify coolant level after engine is shut off and the
coolant is cold. If necessary, repeat coolant ll
procedure Steps 1 through 6.
5-38

(e)Make sure the safety belt reminder light and safety
belt assemblies 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 see Checking
the Restraint Systems on page 1-87.
(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. Check to be sure vent hose
is unobstructed, clear, and free of debris.(h)Change automatic transmission fluid and filter 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, flush, and refill cooling system. This service can
be complex; you should have your dealer/retailer perform
this service. See Engine Coolant on page 5-28for what to
use. Inspect hoses. Clean radiator, condenser, pressure
cap, and ller neck. Pressure test the cooling system and
pressure cap.
(j)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the fluid level checked. Add fluid 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, if the vehicle has one, works
properly. Replace as needed.
6-10

Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp...............................................5-61
Center Seat...................................................1-12
Chains, Tire...................................................5-90
Charging System Light....................................3-43
Check
Engine Light...............................................3-48
Checking Things Under the Hood......................5-12
Chemical Paint Spotting.................................5-120
Child Restraints
Child Restraint Systems...............................1-42
Infants and Young Children...........................1-38
Lower Anchors and Tethers for Children..........1-45
Older Children.............................................1-35
Securing a Child Restraint in a Rear
Seat Position...........................................1-55
Securing a Child Restraint in the Center
Front Seat Position...................................1-57
Securing a Child Restraint in the Right Front
Seat Position...........................1-58, 1-62, 1-66
Where to Put the Restraint...........................1-44
Cigarette Lighter.............................................3-24
Cleaning
Aluminum or Chrome-Plated Wheels.............5-118
Exterior Lamps/Lenses................................5-116
Fabric/Carpet............................................5-114
Finish Care...............................................5-116
Instrument Panel, Vinyl, and Other Plastic
Surfaces...............................................5-115Cleaning (cont.)
Interior.....................................................5-112
Leather....................................................5-114
Tires........................................................5-119
Underbody Maintenance.............................5-119
Washing Your Vehicle.................................5-116
Weatherstrips............................................5-115
Windshield and Wiper Blades......................5-117
Climate Control System...........................3-25, 3-27
Dual Automatic............................................3-28
Outlet Adjustment........................................
3-33
Clock, Setting.................................................3-81
Collision Damage Repair..................................7-11
Compass...............................................2-55, 2-57
Content Theft-Deterrent....................................2-18
Control of a Vehicle.......................................... 4-3
Coolant
Engine Temperature Gage............................3-46
Heater, Engine............................................2-26
Surge Tank Pressure Cap.............................5-30
Cooling System..............................................5-34
Cruise Control................................................3-14
Cruise Control Light........................................3-52
Cupholder(s)..................................................2-75
Customer Assistance Information
Courtesy Transportation.................................. 7-9
Customer Assistance for Text
Telephone (TTY) Users............................... 7-5
Customer Assistance Offices........................... 7-5
3

Electrical System (cont.)
Instrument Panel Fuse Block.......................5-124
Power Windows and Other Power Options....5-123
Underhood Fuse Block...............................5-126
Windshield Wiper Fuses.............................5-123
Engine
Air Cleaner/Filter.........................................5-19
Check and Service Engine Soon Light............3-48
Coolant......................................................5-28
Coolant Heater............................................2-26
Coolant Temperature Gage...........................3-46
Drive Belt Routing.......................................6-18
Engine Compartment Overview......................5-14
Exhaust.....................................................2-53
Fan Noise..................................................5-39
Fast Idle System.........................................2-25
Oil .............................................................5-15
Oil Life System...........................................5-18
Overheated Protection Operating Mode...........5-33
Overheating................................................5-30
Running While Parked..................................2-54
Starting......................................................2-24
Entry Lighting.................................................3-21
Event Data Recorders.....................................7-17
Exit Lighting...................................................3-21
Extender, Safety Belt.......................................1-35
Exterior Lamps...............................................3-17F
Fast Idle System............................................2-25
Filter
Engine Air Cleaner......................................5-19
Finish Damage.............................................5-119
Fixed Mast Antenna.......................................3-126
Flashers, Hazard Warning.................................. 3-8
Flash-to-Pass.................................................3-11
Flat Tire........................................................5-91
Flat Tire, Changing.........................................5-92
Flat Tire, Storing...........................................5-108
Fluid.....................................................5-22, 5-25
Power Steering...........................................5-39
Windshield Washer......................................5-40
Fog Lamp
Fog ...........................................................3-20
Fog Lamp Light..............................................3-52
Four-Wheel Drive....................................2-36, 5-52
Four-Wheel-Drive Light....................................3-53
Front Axle......................................................5-54
Fuel............................................................... 5-6
Additives...................................................... 5-7
California Fuel.............................................. 5-7
E85 (85% Ethanol)........................................ 5-8
Filling a Portable Fuel Container....................5-12
Filling the Tank...........................................5-10
5