2010 GMC SIERRA engine overheat

Starting Procedure
1. With your foot off the accelerator pedal, turn theignition key to START. When the engine starts, let
go of the key. The idle speed will go down as your
engine gets warm. Do not race the engine
immediately after starting it. Operate the engine
and transmission gently to allow the oil to warm up
and lubricate all moving parts.
The vehicle has a Computer-Controlled Cranking
System. This feature assists in starting the engine
and protects components. If the ignition key is
turned to the START position, and then released
when the engine begins cranking, the engine will
continue cranking for a few seconds or until the
vehicle starts. If the engine does not start and the
key is held in START for many seconds, cranking
will be stopped after 15 seconds to prevent
cranking motor damage. To prevent gear damage,
this system also prevents cranking if the engine
is already running. Engine cranking can be
stopped by turning the ignition switch to the
ACC/ACCESSORY or LOCK/OFF position.
Notice: Cranking the engine for long periods of
time, by returning the key to the START position
immediately after cranking has ended, can overheat
and damage the cranking motor, and drain the
battery. Wait at least 15 seconds between each try,
to let the cranking motor cool down. 2. If the engine does not start after 5‐10 seconds,
especially in very cold weather (below 0°F or
−18°C), it could be flooded with too much gasoline.
Try pushing the accelerator pedal all the way to the
floor and holding it there as you hold the key in
START for up to 15 seconds. Wait at least
15 seconds between each try, to allow the cranking
motor to cool down. When the engine starts, let go
of the key and accelerator. If the vehicle starts
briefly but then stops again, do the same thing.
This clears the extra gasoline from the engine.
Do not race the engine immediately after starting it.
Operate the engine and transmission gently until
the oil warms up and lubricates all moving parts.
Notice: The engine is designed to work with the
electronics in the vehicle. If you add electrical
parts or accessories, you could change the way
the engine operates. Before adding electrical
equipment, check with your dealer/retailer. If you
do not, the engine might not perform properly.
Any resulting damage would not be covered by the
vehicle warranty.
3-24

To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.The cord is secured to the Engine Compartment
Fuse Block with a clip. Carefully remove the wire
tie which bundles the electrical plug. Do not cut the
electrical cord.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
{WARNING:
Plugging the cord into an ungrounded outlet could
cause an electrical shock. Also, the wrong kind of
extension cord could overheat and cause a fire.
You could be seriously injured. Plug the cord into
a properly grounded three-prong 110-volt AC
outlet. If the cord will not reach, use a heavy-duty
three-prong extension cord rated for at least
15 amps.
4. Before starting the engine, be sure to unplug and store the cord as it was before to keep it away from
moving engine parts. If you do not, it could be
damaged. The length of time the heater should remain plugged in
depends on several factors. Ask a dealer/retailer in the
area where you will be parking the vehicle for the best
advice on this.
Active Fuel Management™
Vehicles with V8 engines may have Active Fuel
Management™. This system allows the engine to
operate on either all or half of its cylinders, depending
on the driving conditions.
When less power is required, such as cruising at a
constant vehicle speed, the system will operate in the
half cylinder mode, allowing the vehicle to achieve
better fuel economy. When greater power demands are
required, such as accelerating from a stop, passing,
or merging onto a freeway, the system will maintain
full-cylinder operation.
If the vehicle has an Active Fuel Management™
indicator, see
DIC Operation and Displays (With DIC
Buttons)
on page 4‑51or DIC Operation and Displays
(Without DIC Buttons)on page 4‑58for more
information on using this display .
3-27

Leaving the Vehicle With the Engine
Running
{WARNING:
It can be dangerous to leave the vehicle with the
engine running. The vehicle could move suddenly
if the shift lever is not fully in P (Park) with the
parking brake firmly set.
If you have four-wheel drive and the transfer case
is in N (Neutral), the vehicle will be free to roll,
even if the shift lever is in P (Park). So be sure
the transfer case is in a drive gear—not in
N (Neutral).
And, if you leave the vehicle with the engine
running, it could overheat and even catch fire.
You or others could be injured. Do not leave the
vehicle with the engine running unless you
have to. If you have to leave the vehicle with the engine running,
be sure your vehicle is in P (Park) and the parking
brake is firmly set before you leave it. After you move
the shift lever into P (Park), hold the regular brake pedal
down. Then, see if you can move the shift lever away
from P (Park) without first pulling it toward you. If you
can, it means that the shift lever was not fully locked
into P (Park).
Torque Lock
If you are parking on a hill and you do not shift your
transmission into P (Park) properly, the weight of the
vehicle may put too much force on the parking pawl in
the transmission. You may find it difficult to pull the
shift lever out of P (Park). This is called torque lock.
To prevent torque lock, set the parking brake and then
shift into P (Park) properly before you leave the driver
seat. To find out how, see
Shifting Into Park
on
page 3‑51.
When you are ready to drive, move the shift lever out
of P (Park) before you release the parking brake.
If torque lock does occur, you may need to have
another vehicle push yours a little uphill to take some of
the pressure from the parking pawl in the transmission,
then you will be able to pull the shift lever out of
P (Park).
3-52

StabiliTrak®Indicator Light
For vehicles with the
StabiliTrak®system, this
light comes on briefly
while starting the engine.
If it does not, have the vehicle serviced by your
dealer/retailer. If the system is working normally the
indicator light then goes off.
If the light comes on and stays on while driving, there
could be a problem with the StabiliTrak
®system and the
vehicle might need service. When this warning light is
on, the StabiliTrak
®system is off and does not limit
wheel spin.
The light flashes if the system is active and is working
to assist the driver with directional control of the vehicle
in difficult driving conditions.
See StabiliTrak
®Systemon page 5‑6for more
information.
Engine Coolant Temperature Gage
United StatesCanada
This gage shows the engine coolant temperature.
It also provides an indicator of how hard the vehicle is
working. During a majority of the operation, the gage
will read 210°F (100°C) or less. If the vehicle is pulling a
load or going up hills, it is normal for the temperature to
fluctuate and go over the 235°F (113°C) mark. However,
if the gage reaches the 260°F (125°C) mark, it indicates
that the cooling system is working beyond its capacity.
See Engine Overheating on page 6‑34.
4-41

ENGINE OVERHEATED IDLE ENGINE
Notice:If you drive your vehicle while the engine is
overheating, severe engine damage may occur. If an
overheat warning appears on the instrument panel
cluster and/or DIC, stop the vehicle as soon as
possible. See Engine Overheating
on page 6‑34for
more information.
This message displays when the engine coolant
temperature is too hot. Stop and allow the vehicle to
idle until it cools down. See Engine Coolant
Temperature Gage on page 4‑41.
See Overheated Engine Protection Operating Mode
on
page 6‑36for information on driving to a safe place in
an emergency.
ENGINE OVERHEATED STOP ENGINE
Notice: If you drive your vehicle while the engine is
overheating, severe engine damage may occur. If an
overheat warning appears on the instrument panel
cluster and/or DIC, stop the vehicle as soon as
possible. See Engine Overheating
on page 6‑34for
more information.
This message displays and a chime may sound if the
engine cooling system reaches unsafe temperatures for
operation. Stop and turn off the vehicle as soon as it is
safe to do so to avoid severe damage. This message
clears when the engine has cooled to a safe operating
temperature.
ENGINE POWER IS REDUCED
This message displays and a chime may sound when
the cooling system temperature gets too hot and the
engine further enters the engine coolant protection
mode. See Engine Overheating
on page 6‑34for
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. See Fast Idle System
on page 3‑25for more information.
FUEL LEVEL LOW
This message displays and a chime may sound if the
fuel level is low. Refuel as soon as possible. See Fuel
Gage
on page 4‑49and Fuelon page 6‑6for more
information.
4-67

STABILITRAK OFF
If your vehicle has StabiliTrak, this message displays
when you turn off StabiliTrak, or when the stability
control has been automatically disabled. To limit
wheel spin and realize the full benefits of the stability
enhancement system, you should normally leave
StabiliTrak on. However, you should turn StabiliTrak off
if your vehicle gets stuck in sand, mud, ice, or snow and
you want to rock your vehicle to attempt to free it, or if
you are driving in extreme off-road conditions and
require more wheel spin. SeeIf Your Vehicle is Stuck in
Sand, Mud, Ice, or Snow
on page 5‑28. To turn the
StabiliTrak system on or off, see StabiliTrak®Systemon page 5‑6.
There are several conditions that can cause this
message to appear.
.One condition is overheating, which could occur if
StabiliTrak®activates continuously for an extended
period of time.
.The message also displays if the brake system
warning light is on. See Brake System Warning
Light on page 4‑39.
.The message could display if the stability system
takes longer than usual to complete its diagnostic
checks due to driving conditions.
.The message displays if an engine or vehicle
related problem has been detected and the vehicle
needs service. See your dealer/retailer.
.The message also displays if the vehicle is shifted
into 4LO.
The message turns off as soon as the conditions
that caused the message to be displayed are no
longer present.
TIGHTEN GAS CAP
This message may display along with the check engine
light on the instrument panel cluster if the vehicle's fuel
cap is not tightened properly. See Malfunction Indicator
Lamp
on page 4‑42. Reinstall the fuel cap fully. See
Filling the Tankon page 6‑11. The diagnostic system
can determine if the fuel cap has been left off or
improperly installed. A loose or missing fuel cap allows
fuel to evaporate into the atmosphere. A few driving
trips with the cap properly installed should turn this light
and message off.
4-72

TRAILER CONNECTED
On vehicles with the Integrated Trailer Brake
Control (ITBC) system, this message displays
briefly when a trailer with electric brakes is
first connected to the vehicle.
This message clears itself after several seconds. This
message also clears if you acknowledge it. After this
message clears, the TRAILER GAIN/OUTPUT display
appears in the DIC.
See“TRAILER GAIN/OUTPUT” underDIC Operation
and Displays (With DIC Buttons)
on page 4‑51or DIC
Operation and Displays (Without DIC Buttons)on
page 4‑58and “Integrated Trailer Brake Control
System” underTowing a Traileron page 5‑50for
more information.
TRANSMISSION HOT IDLE ENGINE
Notice: If you drive your vehicle while the
transmission fluid is overheating and the
transmission temperature warning is displayed on
the instrument panel cluster and/or DIC, you can
damage the transmission. This could lead to costly
repairs that would not be covered by your warranty.
Do not drive your vehicle with overheated
transmission fluid or while the transmission
temperature warning is displayed. This message displays and a chime may sound if the
transmission fluid in the vehicle gets hot. Driving with
the transmission fluid temperature high can cause
damage to the vehicle. Stop the vehicle and let it idle to
allow the transmission to cool. This message clears and
the chime stops when the fluid temperature reaches a
safe level.
TURN SIGNAL ON
This message displays and a chime may sound if a turn
signal is left on for 3/4 of a mile (1.2 km). Move the turn
signal/multifunction lever to the off position.
WASHER FLUID LOW ADD FLUID
This message displays when the windshield washer
fluid is low. Fill the windshield washer fluid reservoir as
soon as possible. See
Engine Compartment Overview
on page 6‑16for the location of the windshield washer
fluid reservoir. Also, see Windshield Washer Fluidon
page 6‑38for more information.
4-74

{WARNING:
Heavy braking when going down a hill can cause
your brakes to overheat and fade. This could
cause loss of control and a serious accident.
Apply the brakes lightly when descending a
hill and use a low gear to keep vehicle speed
under control.
Things not to do when driving down a hill:
.When driving downhill, avoid turns that take you
across the incline of the hill. A hill that is not too
steep to drive down might be too steep to drive
across. The vehicle could roll over.
.Never go downhill with the transmission in
N (Neutral), called free-wheeling. The brakes will
have to do all the work and could overheat
and fade. Vehicles are much more likely to stall when going uphill,
but if it happens when going downhill:
1. Stop the vehicle by applying the regular brakes and apply the parking brake.
2. Shift to P (Park) and, while still braking, restart the engine.
3. Shift back to a low gear, release the parking brake, and drive straight down.
4. If the engine will not start, get out and get help.
5-19