2012 GMC YUKON check engine

Black plate (33,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-33
3. With the engine off, turn theignition 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
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.
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 11‑3.
Replacement blades come in
different types and are removed in
different ways.
Front Wiper Blade
Replacement
1. Pull the windshield wiper arm connector away from the
windshield.

Black plate (91,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-91
5. Check that the jumper cablesdo 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.
6. Connect the red positive (+)
cable to the positive (+) terminal
of the vehicle with the dead
battery. Use a remote
positive (+) terminal if the
vehicle has one.
7. 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. 8. Now 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. The
other end of the negative (−)
cable does not go to the dead
battery. It goes to a heavy,
unpainted metal engine part or
to the remote negative (−)
terminal on the vehicle with the
dead battery.
9. Connect the other end of the negative (−) cable to the remote
negative (−) terminal, on the
vehicle with the dead battery.
10. Now start the vehicle with the good battery and run the
engine for a while.

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 (8,1)GMC Yukon/Yukon XL Owner Manual - 2012
11-8 Service and Maintenance
Footnotes—Maintenance
Schedule Additional Required
Services —Severe
a) 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.
b) Or every four years, whichever
comes first.
c) Do not directly power wash the
transfer case output seals. High
pressure water can overcome the
seals and contaminate the transfer
case fluid. Contaminated fluid will
decrease the life of the transfer
case and should be replaced.
d) Or every five years, whichever
comes first. See Cooling System on
page 10‑16.
e) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage;
replace, if needed.Special Application
Services
.Severe Commercial Use
Vehicles Only: Lubricate
chassis components every
5 000 km/3,000 mi.
.Have underbody flushing service
performed once a year.
Additional
Maintenance and Care
Your vehicle is an important
investment and caring for it properly
may help to avoid future costly
repairs. To maintain vehicle
performance, additional
maintenance services may be
required. It is recommended that
your dealer perform these
services —their trained dealer
technicians know your vehicle best.
Your dealer can also perform a
thorough assessment with a
multi‐point inspection to recommend
when your vehicle may need
attention. The following list is
intended to explain the services and
conditions to look for that may
indicate services are required.
Battery
The battery supplies power to start
the engine and operate any
additional electrical accessories.

Black plate (9,1)GMC Yukon/Yukon XL Owner Manual - 2012
Service and Maintenance 11-9
.To avoid break‐down or failure to
start the vehicle, maintain a
battery with full cranking power.
.Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion‐free.
Belts
.Belts may need replacing if they
squeak or show signs of
cracking or splitting.
.Trained dealer technicians can
inspect the belts and
recommend replacement when
necessary.
Brakes
Brakes stop the vehicle and are
crucial to safe driving.
.Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping.
.Trained dealer technicians have
access to tools and equipment
to inspect the brakes and
recommend quality parts
engineered for the vehicle.
Fluids
Proper fluid levels and approved
fluids protect the vehicle’s systems
and components. See
Recommended Fluids and
Lubricants on page 11‑11 for GM
approved fluids.
.Engine oil and windshield
washer fluid levels should be
checked at every fuel fill.
.Instrument cluster lights may
come on to indicate that fluids
may be low and need to be
filled.
Hoses
Hoses transport fluids and should
be regularly inspected to ensure
that there are no cracks or leaks.
With a multi‐point inspection, your
dealer can inspect the hoses and
advise if replacement is needed. Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road.
.Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage.
The brake lamps need to be
checked periodically to ensure
that they light when braking.
.With a multi‐point inspection,
your dealer can check the lamps
and note any concerns.
Shocks and Struts
Shocks and struts help aid in control
for a smoother ride.
.Signs of wear may include
steering wheel vibration, bounce/
sway while braking, longer
stopping distance, or uneven
tire wear.

Black plate (12,1)GMC Yukon/Yukon XL Owner Manual - 2012
13-12 Customer Information
Service Publications
Ordering Information
Service Manuals
Service Manuals have the diagnosis
and repair information on the
engines, transmission, axle,
suspension, brakes, electrical,
steering, body, etc.
Service Bulletins
Service Bulletins give additional
technical service information
needed to knowledgeably service
General Motors cars and trucks.
Each bulletin contains instructions
to assist in the diagnosis and
service of the vehicle.
Owner Information
Owner publications are written
specifically for owners and intended
to provide basic operational
information about the vehicle. The
Owner Manual includes the
Maintenance Schedule for all
models.
In-Portfolio: Includes a Portfolio,
Owner Manual, and Warranty
Booklet.
RETAIL SELL PRICE:
$35.00 (U.S.) plus handling and
shipping fees.
Without Portfolio: Owner
Manual only.
RETAIL SELL PRICE:
$25.00 (U.S.) plus handling and
shipping fees.
Current and Past Models
Technical Service Bulletins and
Manuals are available for current
and past model GM vehicles.
ORDER TOLL FREE:
1-800-551-4123 Monday - Friday
8:00 AM - 6:00 PM Eastern Time
For Credit Card Orders Only
(VISA-MasterCard-Discover), visit
Helm, Inc. at: www.helminc.com.
Or write to:
Helm, Incorporated
P.O. Box 07130
Detroit, MI 48207
Prices are subject to change without
notice and without incurring
obligation. Allow ample time for
delivery.
All listed prices are quoted in U.S.
funds. Make checks payable in U.S.
funds.

Black plate (5,1)GMC Yukon/Yukon XL Owner Manual - 2012
OnStar 14-5
Diagnostics
OnStar Vehicle Diagnostics will
perform a vehicle check every
month. It will check the engine,
transmission, antilock brakes, and
major vehicle systems. It also
checks the tire pressures, if the
vehicle is equipped with the Tire
Pressure Monitoring System. If a
diagnostics check is needed
between e-mails, push
Q, and an
Advisor can run a check.
OnStar Additional
Information
Transferring Service
PushQto request account transfer
eligibility information. The Advisor
can assist in canceling or removing
account information. If OnStar
receives information that vehicle
ownership has changed, OnStar
may send a voice message to the
vehicle, requesting updated account
information.
Reactivation for Subsequent
Owners
PushQand follow the prompts to
speak to an Advisor as soon as
possible after acquiring the vehicle.
The Advisor will update vehicle
records and will explain the OnStar
service offers and options available.
How OnStar Service Works
Automatic Crash Response,
Emergency Services, Crisis Assist,
Stolen Vehicle Assistance, Vehicle
Diagnostics, Remote Door Unlock,
Roadside Assistance, Turn-by-Turn
Navigation, and Hands-Free Calling
are available on most vehicles. Not
all OnStar services are available
everywhere or on all vehicles. For
more information, a full description
of OnStar services, system
limitations, and OnStar terms and
conditions, see www.onstar.com
(U.S.) or www.onstar.ca (Canada);
contact OnStar at 1-888-4-ONSTAR
(1‐888‐466‐7827) or TTY 1‐877‐
248‐2080; or push
Qto speak with
an Advisor. OnStar services require
a vehicle electrical system, wireless
service, and GPS satellite
technologies to be available and
operating for features to function
properly. These systems may not
operate if the battery is discharged
or disconnected.