2010 GMC YUKON engine

Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:The vehicle does not need an elaborate
break-in. But it will perform better in the long run if
you follow these guidelines:
.Keep your speed at 55 mph (88 km/h) or less
for the first 500 miles (805 km).
.Do not drive at any one constant speed,
fast or slow, for the first 500 miles (805 km).
Do not make full-throttle starts. Avoid
downshifting to brake or slow the vehicle.
.Avoid making hard stops for the first
200 miles (322 km) or so. During this time
the new brake linings are not yet broken in.
Hard stops with new linings can mean
premature wear and earlier replacement.
Follow this breaking-in guideline every time
you get new brake linings.
.Do not tow a trailer during break-in. See
Towing a Trailer
on page 5‑49for the trailer
towing capabilities of the vehicle and more
information.
Following break‐in, engine speed and load can be
gradually increased.
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B (ACC/ACCESSORY):This position lets things like
the radio and the windshield wipers operate while the
engine is off. Use this position if the vehicle must be
pushed or towed.
C (ON/RUN): This position can be used to operate the
electrical accessories and to display some instrument
panel cluster warning and indicator lights. The switch
stays in this position when the engine is running.
The transmission is also unlocked in this position
on automatic transmission vehicles.
If you leave the key in the ACC/ACCESSORY or
ON/RUN position with the engine off, the battery could
be drained. You may not be able to start the vehicle if
the battery is allowed to drain for an extended period
of time.
D (START): This is the position that starts the engine.
When the engine starts, release the key. The ignition
switch returns to ON/RUN for driving.
A warning tone will sound when the driver door is
opened, the ignition is in ACC/ACCESSORY or
LOCK/OFF and the key is in the ignition.Retained Accessory Power (RAP)
The following vehicle accessories can be used for up to
10 minutes after the engine is turned off:
.Audio System
.Power Windows
.OnStar®System (if equipped)
.Sunroof (if equipped)
These features work when the key is in ON/RUN
or ACC/ACCESSORY. Once the key is turned from
ON/RUN to LOCK/OFF, the windows and sunroof
continue to work up to 10 minutes until any door
is opened. The radio continues to work for up to
10 minutes or until the driver door is opened.
Starting the Engine
If the vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
Move the shift lever to P (Park) or N (Neutral).
The engine will not start in any other position. To restart
the engine when the vehicle is are already moving,
use N (Neutral) only.
Notice: Do not try to shift to P (Park) if the
vehicle is moving. If you do, you could damage
the transmission. Shift to P (Park) only when the
vehicle is stopped.
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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 the
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 a maximum of 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. If you do
not, the engine might not perform properly.
Any resulting damage would not be covered
by the vehicle warranty.
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Adjustable Throttle and Brake Pedal
On vehicles with this feature, you can change the
position of the throttle and brake pedals.
No adjustment to the pedals can be made when the
vehicle is in R (Reverse) or while using the cruise
control.
The switch used to adjust
the pedals is located on
the instrument panel
below the climate control
system.Press the arrow at the bottom of the switch to move the
pedals closer to your body. Press the arrow at the top of
the switch to move the pedals away from your body.
Before you start driving, fully press the brake pedal to
confirm the adjustment is right for you. While driving,
make only small adjustments.
The vehicle may have a memory function which lets
pedal settings be saved and recalled. See
Memory
Seat, Mirrors, and Pedals
on page 2‑10for more
information.
Engine Coolant Heater
The engine coolant heater can provide easier starting
and better fuel economy during engine warm-up in cold
weather conditions at or below −18°C (0°F). Vehicles
with an engine heater should be plugged in at least
four hours before starting. An internal thermostat in
the plug-end of the cord may exist which will prevent
engine coolant heater operation at temperatures above
−18°C (0°F).
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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 secures the electrical cord. 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 in the area
where you will be parking the vehicle for the best advice
on this.
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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, seeDIC Operation and Displays (With DIC
Buttons)
on page 4‑48or DIC Operation and Displays
(Without DIC Buttons)on page 4‑55for more
information on using this display .
Automatic Transmission Operation
If the vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
If the vehicle is has an automatic transmission, it has an
electronic shift position indicator within the instrument
panel cluster. This display comes on when the ignition
key is turned to the ON/RUN position.
There are several different positions for the shift lever.
Hydra-Matic®4-Speed
Automatic Transmission
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Heavy Duty 6-Speed Automatic Transmission Shown(Light Duty Similar)
See “Range Selection Mode” later in this section.
P (Park): This position locks the rear wheels. It is the
best position to use when starting the engine because
the vehicle cannot move easily. When parked on a hill,
especially when the vehicle has a heavy load, you
might notice an increase in the effort to shift out of
P (Park). See Torque Lock (Automatic Transmission)
under Shifting Into Park
on page 3‑49for more
information.
{WARNING:
It is dangerous to get out of the vehicle if the shift
lever is not fully in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the vehicle when the engine is
running unless you have to. If you have left the
engine running, the vehicle can move suddenly.
You or others could be injured. To be sure the
vehicle will not move, even when you are on fairly
level ground, always set the parking brake and
move the shift lever to P (Park). See Shifting Into
Park
on page 3‑49. If you are pulling a trailer,
see Towing a Trailer on page 5‑49.
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{WARNING:
If the vehicle has a four-wheel drive transfer
case with a N (Neutral) position, and the transfer
case is in N (Neutral), the vehicle will be free to
roll—even if the shift lever is in P (Park). Be sure
the transfer case is in a drive gear, Two-Wheel
Drive High or Four-Wheel Drive High or
Four-Wheel Drive Low —not in N (Neutral).
See Shifting Into Park
on page 3‑49. Always
set the parking brake.
R (Reverse): Use this gear to back up.
Notice: Shifting to R (Reverse) while the vehicle is
moving forward could damage the transmission.
The repairs would not be covered by the vehicle
warranty. Shift to R (Reverse) only after the vehicle
is stopped.
To rock the vehicle back and forth to get out of snow,
ice, or sand without damaging the transmission, see If
Your Vehicle is Stuck in Sand, Mud, Ice, or Snow
on
page 5‑29. N (Neutral):
In this position, the engine does not
connect with the wheels. To restart the engine when the
vehicle is already moving, use N (Neutral) only. Also,
use N (Neutral) when the vehicle is being towed.
{WARNING:
Shifting into a drive gear while the engine is
running at high speed is dangerous. Unless your
foot is firmly on the brake pedal, the vehicle could
move very rapidly. You could lose control and hit
people or objects. Do not shift into a drive gear
while the engine is running at high speed.
Notice: Shifting out of P (Park) or N (Neutral) with
the engine running at high speed may damage the
transmission. The repairs would not be covered by
the vehicle warranty. Be sure the engine is not
running at high speed when shifting the vehicle.
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