check engine GMC YUKON 2015 Service Manual

Black plate (22,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
10-22 Vehicle Care
There are only two reasons why the
brake fluid level in the reservoir
might go down:
.The brake fluid level goes down
because of normal brake lining
wear. When new linings are
installed, the fluid level goes
back up.
.A fluid leak in the brake
hydraulic system can also cause
a low fluid level. Have the brake
hydraulic system fixed, since a
leak means that sooner or later
the brakes will not work well.
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove brake fluid,
as necessary, only when work is
done on the brake hydraulic system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged.
Add brake fluid only when work is
done on the brake hydraulic
system. See “Checking Brake
Fluid” in this section.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light on page 5-21.
Refer to the Maintenance Schedule
to determine when to check the
brake fluid. See Maintenance
Schedule on page 11-2.
Checking Brake Fluid
Check brake fluid by looking at the
brake fluid reservoir. See Engine
Compartment Overview on
page 10-5.
The fluid level should be above
MIN. If it is not, have the brake
hydraulic system checked to see if
there is a leak.
After work is done on the brake
hydraulic system, make sure the
level is above MIN but not over the
MAX mark.
What to Add
Use only new DOT 3 brake fluid
from a sealed container. See
Recommended Fluids and
Lubricants on page 11-12.

Black plate (27,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
Vehicle Care 10-27
Starter Switch Check
{Warning
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle.
2. Apply both the parking brake and the regular brake.
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts.
3. Try to start the engine in each gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
Automatic Transmission
Shift Lock Control
Function Check
{Warning
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. It should be
parked on a level surface.
2. Apply the parking brake. Be ready to apply the regular brake
immediately if the vehicle begins
to move.
3. With the engine off, turn the ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.
Ignition Transmission
Lock Check
If equipped with a key type ignition,
while parked and with the parking
brake set, try to turn the ignition to
LOCK/OFF in each shift lever
position.
.The ignition should turn to
LOCK/OFF only when the shift
lever is in P (Park).
.The ignition key should come
out only in LOCK/OFF.
Contact your dealer if service is
required.

Black plate (28,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
10-28 Vehicle Care
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move.
Park on a fairly steep hill, with the
vehicle facing downhill. Keeping
your foot on the regular brake, set
the parking brake.
.To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.
.To check the P (Park)
mechanism's holding ability:
With the engine running, shift to
P (Park). Then release the
parking brake followed by the
regular brake.
Contact your dealer if service is
required.
Wiper Blade Replacement
Windshield wiper blades should be
inspected for wear or cracking. See
Maintenance Schedule on
page 11-2.
For the proper type and size, see
Maintenance Replacement Parts on
page 11-14.
Front Wiper Blade
Replacement
To replace the wiper blade
assembly:
1. Pull the windshield wiper assembly away from the
windshield.
2. Lift up on the latch in the middle
of the wiper blade where the
wiper arm attaches.
3. With the latch open, pull the wiper blade down toward the
windshield far enough to release
it from the J-hooked end of the
wiper arm.
4. Remove the wiper blade. Allowing the wiper blade arm to
touch the windshield when no
wiper blade is installed could
damage the windshield. Any
damage that occurs would not
be covered by the vehicle

Black plate (34,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
10-34 Vehicle Care
headlamp wiring checked right away
if the lamps go on and off or
remain off.
Windshield Wipers
If the wiper motor overheats due to
heavy snow or ice, the windshield
wipers will stop until the motor cools
and will then restart.
Although the circuit is protected
from electrical overload, overload
due to heavy snow or ice may
cause wiper linkage damage.
Always clear ice and heavy snow
from the windshield before using the
windshield wipers.
If the overload is caused by an
electrical problem and not snow or
ice, be sure to get it fixed.
Fuses
The wiring circuits in the vehicle are
protected from short circuits by
fuses. This greatly reduces the
chance of fires caused by electrical
problems.Look at the silver-colored band
inside the fuse. If the band is broken
or melted, replace the fuse. Be sure
you replace a bad fuse with a new
one of the identical size and rating.
Fuses of the same amperage can
be temporarily borrowed from
another fuse location, if a fuse goes
out. Replace the fuse as soon as
you can.
Engine Compartment
Fuse Block
The engine compartment fuse block
is in the engine compartment, on
the driver side of the vehicle.
Lift the cover to access the fuse
block.
{Caution
Spilling liquid on any electrical
component on the vehicle may
damage it. Always keep the
covers on any electrical
component.
A fuse puller is available in the left
instrument panel fuse block.

Black plate (77,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
Vehicle Care 10-77
Jump Starting
For more information about the
vehicle battery, seeBattery on
page 10-23.
If the vehicle's battery (or batteries)
has run down, you may want to use
another vehicle and some jumper
cables to start your vehicle. Be sure
to use the following steps to do it
safely.
{Warning
Batteries can hurt you. They can
be dangerous because:
.They contain acid that can
burn you.
.They contain gas that can
explode or ignite.
.They contain enough
electricity to burn you.
If you do not follow these steps
exactly, some or all of these
things can hurt you.
{Caution
Ignoring these steps could result
in costly damage to the vehicle
that would not be covered by the
vehicle warranty. Trying to start
the vehicle by pushing or pulling it
will not work, and it could damage
the vehicle.
1. Check the other vehicle. It must have a 12-volt battery with a
negative ground system.
{Caution
If the other vehicle does not have
a 12-volt system with a negative
ground, both vehicles can be
damaged. Only use a vehicle that
has a 12-volt system with a
negative ground for jump starting.
2. If the vehicle is equipped with dual batteries, using the battery
that is closer to the starter will reduce electrical resistance. This
is located on the passenger
side, in the rear of the engine
compartment.
3. Get the vehicles close enough so the jumper cables can reach,
but be sure the vehicles are not
touching each other. If they are,
it could cause an unwanted
ground connection. You would
not be able to start your vehicle,
and the bad grounding could
damage the electrical systems.
To avoid the possibility of the
vehicles rolling, set the parking
brake firmly on both vehicles
involved in the jump start
procedure. Put the automatic
transmission in P (Park) or a
manual transmission in Neutral
before setting the parking brake.
If you have a four-wheel-drive
vehicle, be sure the transfer
case is in a drive gear, not in
N (Neutral).

Black plate (79,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
Vehicle Care 10-79
{Warning
Fans or other moving engine
parts can injure you badly. Keep
your hands away from moving
parts once the engine is running.
6. Check that the jumper cables do not have loose or missing
insulation. If they do, you could
get a shock. The vehicles could
be damaged too.
Before you connect the cables,
here are some basic things you
should know. Positive (+) will go
to positive (+) or to a remote
positive (+) terminal if the
vehicle has one. Negative (−)
will go to a heavy, unpainted
metal engine part or to a remote
negative (−) terminal if the
vehicle has one.
Do not connect positive (+) to
negative (−) or you will get a
short that would damage the
battery and maybe other parts too. And do not connect the
negative (−) cable to the
negative (−) terminal on the
dead battery because this can
cause sparks.
7. Connect the red positive (+)
cable to the positive (+) terminal
of the vehicle with the dead
battery.
8. Do not let the other end touch metal. Connect it to the
positive (+) terminal of the good
battery. Use a remote
positive (+) terminal if the
vehicle has one. 9. Connect the black negative (−)
cable to the negative (−) terminal
of the good battery. Use a
remote negative (−) terminal if
the vehicle has one.
Do not let the other end touch
anything until the next step.
10. Connect the other end of the
negative (−) cable to the metal
bracket that is bolted to the
engine and supports the
resonator, on the vehicle with
the dead battery.

Black plate (82,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
10-82 Vehicle Care
{Warning
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or others could
be injured. Set the parking brake
before shifting the transfer case
to N (Neutral).
Follow these steps to dinghy tow:
1. Position the vehicle being towed behind the tow vehicle, facing
forward and on a level surface.
2. Securely attach the vehicle being towed to the tow vehicle.
3. Apply the parking brake and start the engine.
For vehicles with electric parking
brakes, the parking brake cannot
be applied and the tires must be
chocked. 4. Shift the transfer case to
N (Neutral). See “Shifting into
N (Neutral)” underFour-Wheel
Drive on page 9-36 for the
proper procedure. Check that
the vehicle is in N (Neutral) by
shifting the transmission to
R (Reverse) and then to D
(Drive). There should be no
movement of the vehicle while
shifting.
5. With the transmission in D (Drive), turn the ignition to ACC/
ACCESSORY. Vehicles with
Keyless Access, turn the
engine off.
{Caution
Failure to disconnect the negative
battery cable or to have it contact
the terminals can cause damage
to the vehicle.
6. Disconnect the negative battery cable at the battery and secure
the nut and bolt. Cover the negative battery post with a
non-conductive material to
prevent any contact with the
negative battery terminal.
7. Shift the transmission to P (Park).
{Caution
If the steering column is locked,
vehicle damage may occur.
9. Move the steering wheel to make sure the steering column
is unlocked.
10. Release the parking brake.
11. Keep the ignition key in the towed vehicle in ACC/
ACCESSORY to prevent the
steering column from locking.
Vehicles with Keyless Access,
keep the RKA fob outside of
the vehicle, and manually lock
doors. Access vehicle same as
dead vehicle/fob process (back
up key in door lock).

Black plate (83,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
Vehicle Care 10-83
Disconnecting the Towed Vehicle
Before disconnecting the towed
vehicle:
1. Park on a level surface.
2. Set the parking brake, shift thetransmission to P (Park).
3. Connect the battery.
4. Apply the brake pedal.
5. Start the engine, then shift the transfer case out of N (Neutral)
to Two-Wheel Drive High. See
Four-Wheel Drive on page 9-36
for directions on shifting out of
N (Neutral).
6. Check that the vehicle is in Two-Wheel Drive High by
shifting the transmission to
R (Reverse) and then to D
(Drive). There should be
movement of the vehicle while
shifting.
7. Shift the transmission to P (Park) and turn off the ignition.
8. Disconnect the vehicle from the tow vehicle. 9. Release the parking brake.
10. Reset any lost presets.
The outside temperature
display will default to 32°F but
will reset with normal usage.
Dolly Towing –Front Towing
(Front Wheels Off the Ground)
Two-Wheel-Drive Vehicles and
Four-Wheel Drive Vehicles with a
Single Speed Automatic
Transfer Case
{Caution
If a two-wheel-drive vehicle is
towed with the rear wheels on the
ground, the transmission could be
damaged. The repairs would not
be covered by the vehicle
warranty. Never tow the vehicle
with the rear wheels on the
ground.
Two-wheel-drive vehicles and
four-wheel drive vehicles with a
single speed automatic transfer
case should not be towed with the
rear wheels on the ground.
Two-wheel-drive transmissions have
no provisions for internal lubrication
while being towed. Four-wheel drive
vehicles with a single speed
automatic transfer case have no
neutral position and will spin the
transmission when the rear
wheels turn.

Black plate (2,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
11-2 Service and Maintenance
Because of the way people use
vehicles, maintenance needs vary.
There may need to be more
frequent checks and services. The
Additional Required Services -
Normal are for vehicles that:
.Carry passengers and cargo
within recommended limits on
the Tire and Loading Information
label. SeeVehicle Load Limits
on page 9-14.
.Are driven on reasonable road
surfaces within legal driving
limits.
.Use the recommended fuel. See
Fuel on page 9-70.
Refer to the information in the
Maintenance Schedule Additional
Required Services - Normal chart.
The Additional Required Services -
Severe are for vehicles that are:
.Mainly driven in heavy city traffic
in hot weather.
.Mainly driven in hilly or
mountainous terrain.
.Frequently towing a trailer.
.Used for high speed or
competitive driving.
.Used for taxi, police, or delivery
service.
Refer to the information in the
Maintenance Schedule Additional
Required Services - Severe chart.
{Warning
Performing maintenance work can
be dangerous and can cause
serious injury. Perform
maintenance work only if the
required information, proper tools,
and equipment are available.
If they are not, see your dealer to
have a trained technician do the
work. See Doing Your Own
Service Work on page 10-3.
Maintenance
Schedule
Owner Checks and Services
At Each Fuel Stop
.Check the engine oil level. See
Engine Oil on page 10-6.
Once a Month
.Check the tire inflation
pressures. See Tire Pressure on
page 10-51.
.Inspect the tires for wear. See
Tire Inspection on page 10-58.
.Check the windshield washer
fluid level. See Washer Fluid on
page 10-20.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km/600 mi. If driven
under the best conditions, the
engine oil life system might not
indicate the need for vehicle service

Black plate (3,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
Service and Maintenance 11-3
for more than a year. The engine oil
and filter must be changed at least
once a year and the oil life system
must be reset. Your trained dealer
technician can perform this work.
If the engine oil life system is reset
accidentally, service the vehicle
within 5 000 km/3,000 mi since the
last service. Reset the oil life
system when the oil is changed.
SeeEngine Oil Life System on
page 10-9.
Tire Rotation and Required
Services Every 12 000 km/
7,500 mi
Rotate the tires, if recommended for
the vehicle, and perform the
following services. See Tire
Rotation on page 10-58.
.Check engine oil level and oil
life percentage. If needed,
change engine oil and filter, and
reset oil life system. See Engine
Oil on page 10-6 andEngine Oil
Life System on page 10-9.
.Check engine coolant level. See
Engine Coolant on page 10-15.
.Check windshield washer fluid
level. See Washer Fluid on
page 10-20.
.Visually inspect windshield wiper
blades for wear, cracking,
or contamination. See Exterior
Care on page 10-86. Replace
worn or damaged wiper blades.
See Wiper Blade Replacement
on page 10-28.
.Check tire inflation pressures.
See Tire Pressure on
page 10-51.
.Inspect tire wear. See Tire
Inspection on page 10-58.
.Visually check for fluid leaks.
.Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter on
page 10-13.
.Inspect brake system.
.Visually inspect steering,
suspension, and chassis
components for damaged, loose, or missing parts or signs of wear
at least once a year. See
Exterior Care on page 10-86.
Lubricate the suspension and
steering components at least
every other oil
change. (If equipped with grease
fittings)
.Check restraint system
components. See
Safety System
Check on page 3-27.
.Visually inspect fuel system for
damage or leaks.
.Visually inspect exhaust system
and nearby heat shields for
loose or damaged parts.
.Lubricate body components. See
Exterior Care on page 10-86.
.Check starter switch. See Starter
Switch Check on page 10-27.
.Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function Check on
page 10-27.