2012 GMC YUKON engine coolant

Black plate (21,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-21
4. With the coolant surge tankpressure cap off, start the
engine and let it run until the
upper radiator hose can be felt
getting hot. Watch out for the
engine cooling fan.
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. 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
fill procedure Steps 1 through 6.
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.
Engine Overheating
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge on your vehicle's instrument
panel. See Engine Coolant
Temperature Gauge on page 5‑16. In addition, ENGINE OVERHEATED
STOP ENGINE, ENGINE
OVERHEATED IDLE ENGINE, and
an ENGINE POWER IS REDUCED
message comes on in the Driver
Information Center (DIC) on the
instrument panel. See
Engine
Cooling System Messages on
page 5‑39 andEngine Power
Messages on page 5‑41.
If the decision is made not to lift the
hood when this warning appears,
but instead get service help right
away. See Roadside Assistance
Program on page 13‑5.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.

Black plate (22,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-22 Vehicle Care
Then check to see if the engine
cooling fans are running. If the
engine is overheating, both fans
should be running. If they are not,
do not continue to run the engine
and have the vehicle serviced.
Notice:Engine damage from
running the engine without
coolant is not covered by the
vehicle warranty. See Overheated
Engine Protection Operating
Mode on page 10‑23 for
information on driving to a safe
place in an emergency.
Notice: If the engine catches fire
while driving with no coolant, the
vehicle can be badly damaged.
The costly repairs would not be
covered by the vehicle warranty.
See Overheated Engine
Protection Operating Mode on
page 10‑23 for information on
driving to a safe place in an
emergency.If Steam Is Coming from the
Engine Compartment
{WARNING
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or hear
steam coming from it. Turn it off
and get everyone away from the
vehicle until it cools down. Wait
until there is no sign of steam or
coolant before you open
the hood.
If you keep driving when the
vehicles engine is overheated,
the liquids in it can catch fire. You
or others could be badly burned.
Stop the engine if it overheats,
and get out of the vehicle until the
engine is cool.
(Continued)
WARNING (Continued)
SeeOverheated Engine
Protection Operating Mode on
page 10‑23 for information on
driving to a safe place in an
emergency.
If No Steam Is Coming from
the Engine Compartment
The ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem.
If an engine overheat warning is
displayed but no steam can be seen
or heard, the problem may not be
too serious. Sometimes the engine
can get a little too hot when the
vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.

Black plate (23,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-23
.Idles for long periods in traffic.
.Tows a trailer. SeeTrailer
Towing on page 9‑72.
If the overheat warning is displayed
with no sign of steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest
fan speed. Open the windows as
necessary.
3. In heavy traffic, let the engine idle in N (Neutral) while stopped.
If it is safe to do so, pull off the
road, shift to P (Park) or
N (Neutral) and let the
engine idle.
If the temperature overheat gauge
is no longer in the overheat zone
or an overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally. If the warning continues, pull
over, stop, and park the vehicle
right away.
If there is no sign of steam, idle
the engine for three minutes
while parked. If the warning is still
displayed, turn off the engine until it
cools down. Also, see
“Overheated
Engine Protection Operating Mode”
later in this section.
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message is displayed,
an overheat protection mode which
alternates firing groups of cylinders
helps prevent engine damage. In
this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe place
in an emergency. Driving extended distances and/or towing a trailer in
the overheat protection mode
should be avoided.
Notice:
After driving in the
overheated engine protection
operating mode, to avoid engine
damage, allow the engine to cool
before attempting any repair.
The engine oil will be severely
degraded. Repair the cause of
coolant loss, change the oil and
reset the oil life system. See
Engine Oil on page 10‑8.
Engine Fan
If the vehicle has a clutched engine
cooling fan, when the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and the
clutch is not fully engaged.
This improves fuel economy and
reduces fan noise. Under heavy
vehicle loading, trailer towing, and/
or high outside temperatures, the
fan speed increases as the clutch

Black plate (25,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-25
The level should be at the FULL
COLD mark. If necessary, add only
enough fluid to bring the level up to
the mark.
What to Use
To determine what kind of fluid to
use, seeRecommended Fluids and
Lubricants on page 11‑11. Always
use the proper fluid.
Notice: Use of the incorrect fluid
may damage the vehicle and the
damages may not be covered by
the vehicle's warranty. Always
use the correct fluid listed in
Recommended Fluids and
Lubricants on page 11‑11.
Washer Fluid
What to Use
When windshield washer fluid needs
to be added, be sure to read the
manufacturer's instructions before
use. Use a fluid that has sufficient
protection against freezing in an
area where the temperature may fall
below freezing.
Adding Washer Fluid
The vehicle has a low washer fluid
message on the DIC that comes
on when the washer fluid is low.
The message is displayed for
15 seconds at the start of each
ignition cycle. When the WASHER
FLUID LOW ADD FLUID message
displays, washer fluid will need to
be added to the windshield washer
fluid reservoir.
Open the cap with the washer
symbol on it. Add washer fluid until
the tank is full. See Engine
Compartment Overview on
page 10‑6 for reservoir location. Notice
.When using concentrated
washer fluid, follow the
manufacturer's instructions
for adding water.
.Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
to freeze and damage the
washer fluid tank and other
parts of the washer system.
Also, water does not clean as
well as washer fluid.
.Fill the washer fluid tank only
three-quarters full when it is
very cold. This allows for
fluid expansion if freezing
occurs, which could damage
the tank if it is
completely full.
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system
and paint.

Black plate (3,1)GMC Yukon/Yukon XL Owner Manual - 2012
Service and Maintenance 11-3
Maintenance
Schedule
Owner Checks and Services
At Each Fuel Stop
.Check the engine oil level. See
Engine Oil on page 10‑8.
Once a Month
.Check the tire inflation
pressures. See Tire Pressure on
page 10‑56.
.Inspect the tires for wear. See
Tire Inspection on page 10‑62.
.Check the windshield washer
fluid level. See Washer Fluid on
page 10‑25.
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
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.
See Engine Oil Life System on
page 10‑10.
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 10‑62.
.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 10‑8 andEngine Oil
Life System on page 10‑10.
.Check engine coolant level. See
Engine Coolant on page 10‑17.
.Check windshield washer fluid
level. See Washer Fluid on
page 10‑25.

Black plate (4,1)GMC Yukon/Yukon XL Owner Manual - 2012
11-4 Service and Maintenance
.Visually inspect windshield wiper
blades for wear, cracking,
or contamination. SeeExterior
Care on page 10‑98. Replace
worn or damaged wiper blades.
See Wiper Blade Replacement
on page 10‑33.
.Check tire inflation pressures.
See Tire Pressure on
page 10‑56.
.Inspect tire wear. See Tire
Inspection on page 10‑62.
.Visually check for fluid leaks.
.Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter on
page 10‑15.
.Inspect brake system.
.Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of
wear. See Exterior Care on
page 10‑98.
.Check restraint system
components. See Safety System
Check on page 3‑29.
.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 10‑98.
.Check starter switch. See Starter
Switch Check on page 10‑32.
.Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function Check on
page 10‑32.
.Check ignition transmission lock.
See Ignition Transmission Lock
Check on page 10‑33.
.Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism Check on
page 10‑33.
.Check accelerator pedal for
damage, high effort, or binding.
Replace if needed.
.Visually inspect gas strut for
signs of wear, cracks, or other
damage. Check the hold open
ability of the strut. See your
dealer if service is required.
.Inspect sunroof track and seal,
if equipped. See Sunroof on
page 2‑22.
.Check hybrid low pressure
coolant level, if equipped.

Black plate (11,1)GMC Yukon/Yukon XL Owner Manual - 2012
Service and Maintenance 11-11
Recommended Fluids, Lubricants, and Parts
Recommended Fluids and Lubricants
Fluids and lubricants identified below by name, part number, or specification can be obtained from your dealer.Usage Fluid/Lubricant
Engine Oil Use only engine oil licensed to the dexos1 specfication, or equivalent, of
the proper SAE viscosity grade. ACDelco dexos1 Synthetic Blend is
recommended. See
Engine Oil on page 10‑8.
Engine Coolant 50/50 mixture of clean, drinkable water and use only DEX-COOL Coolant.
See
Engine Coolant on page 10‑17.
Hydraulic Brake System DOT 3 Hydraulic Brake Fluid (GM Part No. 12377967, in
Canada 89021320).
Windshield Washer Optikleen
®Washer Solvent.
Power Steering System GM Power Steering Fluid (GM Part No. 89021184, in Canada 89021186).
Automatic Transmission DEXRON
®-VI Automatic Transmission Fluid.
Key Lock Cylinders Multi-Purpose Lubricant, Superlube (GM Part No. 12346241, in
Canada 10953474).
Chassis Lubrication Chassis Lubricant (GM Part No. 12377985, in Canada 88901242) or
lubricant meeting requirements of NLGI #2, Category LB or GC-LB.
Front Axle (1500 Series Vehicles with Four-Wheel Drive) SAE 80W-90 Axle Lubricant (GM Part No. 89021671, in
Canada 89021672).

Black plate (3,1)GMC Yukon/Yukon XL Owner Manual - 2012
INDEX i-3
Chains, Tire . . . . . . . . . . . . . . . . . . 10-70
Charging System Light . . . . . . . . 5-20
CheckEngine Light . . . . . . . . . . . . . . . . . . 5-21
IgnitionTransmission Lock . . . . . . . . 10-33
Child Restraints
Infants and YoungChildren . . . . . . . . . . . . . . . . . . . . . 3-47
Lower Anchors and Tethers for Children . . . . . . . . . 3-53
Older Children . . . . . . . . . . . . . . . . 3-45
Securing . . . . . . . . . . . . . . . . 3-60, 3-63
Systems . . . . . . . . . . . . . . . . . . . . . . 3-50
Circuit Breakers . . . . . . . . . . . . . . 10-40
Cleaning Exterior Care . . . . . . . . . . . . . . . 10-98
Interior Care . . . . . . . . . . . . . . . 10-101
Climate Control Systems . . . . . . . 8-1 Air Conditioning . . . . . . . . . . . . . . . 8-1
Dual Automatic . . . . . . . . . . . . . . . . 8-4
Heating . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Rear . . . . . . . . . . . . . . . . . . . . 8-10, 8-11 Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Cluster, Instrument . . . . . . . . . . . . 5-12
Collision Damage Repair . . . . . . 13-9
Compass . . . . . . . . . . . . . . . . . . . . . . . 5-6
Connections, OnStar
®. . . . . . . . . 14-4
Continuous Damping Control (CDC) . . . . . . . . . . . . . . . . 9-50
Control of a Vehicle . . . . . . . . . . . . . 9-3
Convex Mirrors . . . . . . . . . . . . . . . . 2-17
Coolant Engine . . . . . . . . . . . . . . . . . . . . . . 10-17
Engine Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 5-16
Cooling System . . . . . . . . . . . . . . . 10-16 Engine Messages . . . . . . . . . . . . 5-39
Courtesy Transportation
Program . . . . . . . . . . . . . . . . . . . . . . 13-8
Cover Cargo . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Cruise Control . . . . . . . . . . . . . . . . . 9-51 Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
Cupholders . . . . . . . . . . . . . . . . . . . . . 4-1 Customer Assistance . . . . . . . . . . 13-4
Offices . . . . . . . . . . . . . . . . . . . . . . . . 13-3
Text Telephone (TTY)
Users . . . . . . . . . . . . . . . . . . . . . . . 13-4
Customer Information Service PublicationsOrdering Information . . . . . . 13-12
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . 13-1
D
Damage Repair, Collision . . . . . . 13-9
Danger, Warnings, andCautions . . . . . . . . . . . . . . . . . . . . . . . . iv
Data Recorders, Event . . . . . . . 13-14
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 6-3
Defensive Driving . . . . . . . . . . . . . . . 9-3
Delayed Locking . . . . . . . . . . . . . . . . 2-8
Devices, Auxiliary . . . . . . . . . . . . . 7-30
Diagnostics, OnStar
®. . . . . . . . . . 14-5
Distracted Driving . . . . . . . . . . . . . . . 9-2
Dome Lamps . . . . . . . . . . . . . . . . . . . 6-8