check transmission fluid GMC YUKON 2012 Owner's Manual

Black plate (45,1)GMC Yukon/Yukon XL Owner Manual - 2012
Instruments and Controls 5-45
is re-learning the tire positions on
your vehicle. The tire positions must
be re-learned after rotating the tires
or after replacing a tire or sensor.
SeeTire Inspection on page 10‑62,
Tire Rotation on page 10‑62, Tire
Pressure Monitor System on
page 10‑58, and Tire Pressure on
page 10‑56 for more information.
TIRE LOW ADD AIR TO TIRE
On vehicles with the Tire Pressure
Monitor System (TPMS), this
message displays when the
pressure in one or more of the
vehicle's tires needs to be checked.
This message also displays LEFT
FRT (left front), RIGHT FRT (right
front), LEFT RR (left rear),
or RIGHT RR (right rear) to indicate
the location of the low tire. The low
tire pressure warning light will also
come on. See Tire Pressure Light
on page 5‑26. You can receive more
than one tire pressure message at a
time. To read the other messages
that may have been sent at the same time, press the set/reset
button or the trip odometer reset
stem. If a tire pressure message
appears on the DIC, stop as soon
as you can. Have the tire pressures
checked and set to those shown on
the Tire Loading Information label.
See
Tires on page 10‑48, Vehicle
Load Limits on page 9‑16, and Tire
Pressure on page 10‑56. The DIC
also shows the tire pressure values.
See “DIC Operation and Displays
(With DIC Buttons)” earlier in this
section.
Transmission Messages
SERVICE 4 WHEEL DRIVE
This message displays if a problem
occurs with the four-wheel-drive
system. If this message appears,
stop as soon as possible and turn
off the vehicle. Make sure the key is
in the LOCK/OFF position for at
least one minute and then restart
the vehicle and check for the
message on the DIC display. If the message is still displayed or
appears again when you begin
driving, the four-wheel-drive system
needs service. See your dealer.
TRANSMISSION HOT IDLE
ENGINE
Notice:
If you drive the 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 the warranty. Do not
drive the vehicle with overheated
transmission fluid or while the
transmission temperature
warning is displayed.
This message displays along with a
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.

Black plate (13,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-13
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips for
driving in these conditions include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Shift to a lower gear when going
down steep or long hills.
{WARNING
If you do not shift down, the
brakes could get so hot that they
would not work well. You would
then have poor braking or even
none going down a hill. You could
crash. Shift down to let the engine
assist the brakes on a steep
downhill slope.
{WARNING
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. The brakes will have
to do all the work of slowing down
and they could get so hot that
they would not work well. You
would then have poor braking or
even none going down a hill. You
could crash. Always have the
engine running and the vehicle in
gear when going downhill.
.Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in your
own lane.
.Be alert on top of hills,
something could be in your lane
(stalled car, accident).
.Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is snow
or ice between the tires and the
road, creating less traction or grip.
Wet ice can occur at about 0°C
(32°F) when freezing rain begins to
fall, resulting in even less traction.
Avoid driving on wet ice or in
freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the
condition. Accelerate gently so
traction is not lost. Accelerating too
quickly causes the wheels to spin
and makes the surface under the
tires slick, so there is even less
traction.

Black plate (71,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-71
3. When the wheel chocks are inplace, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. If the vehicle is four-wheel-drive and has a two-speed transfer
case, be sure the transfer case
is in a drive gear and not in
N (Neutral).
6. Release the brake pedal.
{WARNING
It can be 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.
If the engine has been left
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will (Continued)
WARNING (Continued)
not move, even when on fairly
level ground, use the steps that
follow.
Always put the shift lever fully in
P (Park) with the parking brake
firmly set.
If the transfer case on a
four-wheel-drive vehicle 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 —not in
N (Neutral).
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear. 4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is
clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance When Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11‑3. Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.

Black plate (1,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-3
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . . 10-8
Engine Oil Life System . . . . . 10-10
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-12
Engine Air Cleaner/Filter . . . . 10-15
Cooling System . . . . . . . . . . . . 10-16
Engine Coolant . . . . . . . . . . . . . 10-17 Engine Overheating . . . . . . . . 10-21
Overheated Engine
Protection
Operating Mode . . . . . . . . . . . 10-23
Engine Fan . . . . . . . . . . . . . . . . . 10-23
Power Steering Fluid . . . . . . . 10-24
Washer Fluid . . . . . . . . . . . . . . . 10-25
Brakes . . . . . . . . . . . . . . . . . . . . . 10-26
Brake Fluid . . . . . . . . . . . . . . . . . 10-27
Battery . . . . . . . . . . . . . . . . . . . . . 10-28
Four-Wheel Drive . . . . . . . . . . . 10-29
Front Axle . . . . . . . . . . . . . . . . . . 10-30
Rear Axle . . . . . . . . . . . . . . . . . . 10-31
Starter Switch Check . . . . . . . 10-32
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-32
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-33
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-33
Wiper Blade Replacement . . . . . . . . . . . . . . 10-33
Glass Replacement . . . . . . . . 10-34
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-35
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-37
Halogen Bulbs . . . . . . . . . . . . . . 10-37
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-37
License Plate Lamp . . . . . . . . 10-38
Replacement Bulbs . . . . . . . . . 10-39
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-39
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-40
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-41
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-45
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-48
Tire Sidewall Labeling . . . . . . 10-50
Tire Designations . . . . . . . . . . . 10-52
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . 10-53
Tire Pressure . . . . . . . . . . . . . . . 10-56
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-58

Black plate (7,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-7
A.Engine Air Cleaner/Filter on
page 10‑15.
B. Coolant Surge Tank and Pressure Cap. See Cooling
System on page 10‑16.
C. Remote Positive (+) Terminal. See Jump Starting on
page 10‑88.
D. Battery on page 10‑28.
E. Remote Negative (−) Terminal (Out of View). See Jump
Starting on page 10‑88.
F. Automatic Transmission Dipstick (Out of View). See
“Checking the Fluid Level”
under Automatic Transmission
Fluid on page 10‑12. G. Engine Oil Fill Cap. See
“When
to Add Engine Oil” under
Engine Oil on page 10‑8.
H. Engine Oil Dipstick (Out of View). See “Checking Engine
Oil” under Engine Oil on
page 10‑8.
I. Engine Cooling Fan (Out of View). See Cooling System on
page 10‑16.
J. Power Steering Fluid Reservoir. See Power Steering Fluid on
page 10‑24. K. Brake Master Cylinder
Reservoir. See “Brake Fluid”
under Brake Fluid on
page 10‑27.
L. Engine Compartment Fuse
Block on page 10‑41.
M. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10‑25.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.

Black plate (12,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-12 Vehicle Care
Automatic Transmission
Fluid
When to Check and Change
Automatic Transmission Fluid
It is usually not necessary to
check the transmission fluid level.
The only reason for fluid loss is a
transmission leak or overheated
transmission. If a small leak is
suspected, then use the following
checking procedures to check the
fluid level. However, if there is a
large leak, then it may be necessary
to have the vehicle towed to a
dealer and have it repaired before
driving the vehicle further.
Notice:Use of the incorrect
automatic transmission fluid may
damage the vehicle, and the
damages may not be covered by
the vehicle warranty. Always use
the automatic transmission fluid
listed in Recommended Fluids
and Lubricants on page 11‑11. Change the fluid and filter at the
scheduled maintenance intervals
listed in
Maintenance Schedule on
page 11‑3. Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants on page 11‑11.
How to Check Automatic
Transmission Fluid
Notice: Too much or too
little fluid can damage the
transmission. Too much can
mean that some of the fluid could
come out and fall on hot engine
parts or exhaust system parts,
starting a fire. Too little fluid
could cause the transmission
to overheat. Be sure to get an
accurate reading if checking the
transmission fluid. Before checking the fluid level,
prepare the vehicle as follows:
1. Start the engine and park the
vehicle on a level surface. Keep
the engine running.
2. Apply the parking brake and place the shift lever in P (Park).
3. With your foot on the brake pedal, move the shift lever
through each gear range,
pausing for about three seconds
in each range. Then, move the
shift lever back to P (Park).
4. Allow the engine to idle (500 –800 rpm) for at least
1 minute. Slowly release the
brake pedal.
5. Keep the engine running and press the Trip/Fuel button or
trip odometer reset stem until
TRANS TEMP (Transmission
Temperature) displays on the
Driver Information Center (DIC).

Black plate (13,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-13
6. Using the TRANS TEMPreading, determine and
perform the appropriate check
procedure. If the TRANS TEMP
reading is not within the required
temperature ranges, allow the
vehicle to cool, or operate the
vehicle until the appropriate
transmission fluid temperature is
reached.
Cold Check Procedure
Use this procedure only as a
reference to determine if the
transmission has enough fluid to be
operated safely until a hot check
procedure can be made. The hot
check procedure is the most
accurate method to check the fluid
level. Perform the hot check
procedure at the first opportunity.
Use this cold check procedure to
check fluid level when the
transmission temperature is
between 27°C and 32°C
(80°F and 90°F).
1. Locate the transmission dipstick at the rear of the engine
compartment, on the passenger
side of the vehicle.
See Engine Compartment
Overview on page 10‑6 for more
information.
2. Flip the handle up, then pull out the dipstick and wipe it with a
clean rag or paper towel.
3. Install the dipstick by pushing it back in all the way; wait
three seconds, and then pull it
back out again.
4. Check both sides of the dipstick and read the lower level. Repeat
the check procedure to verify the
reading.5. If the fluid level is below theCOLD check band, add only
enough fluid as necessary to
bring the level into the COLD
band. It does not take much
fluid, generally less than 0.5 L
(1 pt). Do not overfill.
6. Perform a hot check at the first opportunity after the
transmission reaches a normal
operating temperature between
71°C to 93°C (160°F to 200°F).
7. If the fluid level is in the acceptable range, push the
dipstick back in all the way, then
flip the handle down to lock the
dipstick in place.

Black plate (14,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-14 Vehicle Care
Hot Check Procedure
Use this procedure to check the
transmission fluid level when the
transmission fluid temperature is
between 71°C and 93°C (160°F
and 200°F).
The hot check is the most accurate
method to check the fluid level. The
hot check should be performed at
the first opportunity in order to verify
the cold check. The fluid level rises
as fluid temperature increases,
so it is important to ensure the
transmission temperature is within
range.
1. Locate the transmission dipstickat the rear of the engine
compartment, on the passenger
side of the vehicle.
See Engine Compartment
Overview on page 10‑6 for more
information.
2. Flip the handle up, then pull out the dipstick and wipe it with a
clean rag or paper towel.
3. Install the dipstick by pushing it back in all the way; wait
three seconds, and then pull it
back out again.
4. Check both sides of the dipstick and read the lower level. Repeat
the check procedure to verify the
reading.5. Safe operating level is within theHOT cross hatch band on the
dipstick. If the fluid level is not
within the HOT band, and the
transmission temperature is
between 71°C and 93°C (160°F
and 200°F), add or drain fluid as
necessary to bring the level into
the HOT band. If the fluid level is
low, add only enough fluid to
bring the level into the HOT
band. It does not take much
fluid, generally less than 0.5 L
(1 pt). Do not overfill.
6. If the fluid level is in the acceptable range, push the
dipstick back in all the way, then
flip the handle down to lock the
dipstick in place.

Black plate (24,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-24 Vehicle Care
more fully engages, so an increase
in fan noise may be heard. This is
normal and should not be mistaken
as the transmission slipping or
making extra shifts. It is merely the
cooling system functioning properly.
The fan will slow down when
additional cooling is not required
and the clutch disengages.
This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fans, the fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer
towing, high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly.The fans will change to low speed
when additional cooling is no longer
required.
Power Steering Fluid
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
See
Engine Compartment Overview
on page 10‑6 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
How to Check Power Steering
Fluid
Notice:Extremely small amounts
of contamination can cause
steering system damage and
cause it to not work properly. Do
not allow contaminants to contact
the fluid side of the reservoir
cap/dipstick or from entering the
reservoir.
To check the power steering fluid:
1. Turn the key off and let the engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level on the dipstick.

Black plate (32,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-32 Vehicle Care
.For the 2500 series, the proper
level is from 0 mm to 13 mm
(0 in to 1/2 in) below the bottom
of the fill plug hole, located at
the front of the axle. Add only
enough fluid to reach the proper
level.
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. Firmly apply both the parking
brake and the regular brake.
See Parking Brake on
page 9‑45.
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. Firmly apply the parking brake. See Parking Brake on
page 9‑45.
Be ready to apply the regular
brake immediately if the vehicle
begins to move.