
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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292 Vehicle Care
1. Locate the transmissiondipstick at the rear of the
engine compartment, on the
passenger side of the vehicle.
See Engine Compartment
Overview 0284.
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. 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
dipstick at the rear of the
engine compartment, on the
passenger side of the vehicle.
See Engine Compartment
Overview 0284.

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Vehicle Care 293
2. Flip the handle up, then pull outthe 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
the HOT 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.
Consistency of Readings
Always check the fluid level at least
twice using the procedure described
previously. Consistency (repeatable
readings) is important to maintaining
proper fluid level. If readings are still
inconsistent, contact the dealer.
Automatic Transmission
Fluid (8 and 10 Speed
Transmission)
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. This vehicle is not
equipped with a transmission fluid
level dipstick. There is a special
procedure for checking and
changing the transmission fluid in
these vehicles. Because this
procedure is difficult, this should be
done at the dealer. Contact the
dealer for additional information or
the procedure can be found in the
service manual. See
Service
Publications Ordering Information
0 401.
Caution
Use of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
not be covered by the vehicle
warranty. Always use the
automatic transmission fluid listed
in Recommended Fluids and
Lubricants 0384.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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298 Vehicle Care
Turn the pressure cap slowly
counterclockwise about one full
turn. If a hiss is heard, wait for
that to stop. A hiss means
there is still some pressure left.
2. Keep turning the pressure cap slowly, and remove it.
3. Fill the coolant surge tank with the proper mixture to the full
cold mark.
4. With the coolant surge tank pressure cap off, start the
engine and let it run until the
engine coolant temperature
gauge indicates approximately
90 °C (195 °F).
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 tightly. 6. Verify coolant level after the
engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1–6.
Caution
If the pressure cap is not tightly
installed, coolant loss and engine
damage may occur. Be sure the
cap is properly and tightly
secured.
Engine Overheating
Caution
Do not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all
coolant and can damage the
system and vehicle. Have any
leaks fixed right away.
The vehicle has several indicators
to warn of engine overheating. There is a coolant temperature
gauge in the vehicle's instrument
cluster. See
Engine Coolant
Temperature Gauge 0141.
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program
0 396.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
Check to see if the engine cooling
fan(s) are running. If the engine is
overheating, the fans should be
running. If they are not, do not
continue to run the engine. Have the
vehicle serviced.

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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 Access
ignition, while parked and with the
parking brake set, try to turn the
ignition off in each shift lever
position.
.The ignition should turn off only
when the shift lever is in
P (Park).
. The key should come out only
when the ignition is 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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308 Vehicle Care
.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.
For the proper type and size, see
Maintenance Replacement Parts
0 386.
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 warranty. Do not allow the
wiper blade arm to touch the
windshield.
5. Reverse Steps 1–3 for wiper blade replacement.
Rear Wiper Blade Replacement
To replace the rear wiper blade:
1. With the rear wiper in the off position, open the liftglass to
access the rear wiper arm/
blade.
The rear wiper blade will not
lock in a vertical position so
care should be used when
pulling it away from the vehicle.

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Vehicle Care 311
Bulb Replacement
For the proper type of replacement
bulbs, or any bulb changing
procedure not listed in this section,
contact your dealer.
High Intensity Discharge
(HID) Lighting
{Warning
The High Intensity Discharge
(HID) lighting system operates at
a very high voltage. If you try to
service any of the system
components, you could be
seriously injured. Have your
dealer or a qualified technician
service them.
After an HID headlamp bulb has
been replaced, the beam might be a
slightly different shade than it was
originally. This is normal.
LED Lighting
This vehicle has several LED lamps.
For replacement of any LED lighting
assembly, contact your dealer.
Fog Lamps
To replace the front fog lamp bulb: 1. Locate the fog lamp under the front bumper.
2. Disconnect the electrical connector from the fog lamp
bulb assembly by pressing the
connector release. 3. Turn the bulb counterclockwise
to remove it from the housing.
Back-Up Lamps
To replace a back-up bulb:
1. Open the liftgate. See Liftgate
0 45.
2. Remove the taillamp closeout
cover from the lamp assembly
by pulling rearward from the
top and bottom at the same
time to unfasten the snap tabs.

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312 Vehicle Care
3. Remove the two screws fromthe taillamp assembly.
4. Pull the taillamp assembly straight back to remove.5. Turn the bulb socketcounterclockwise to remove it
from the taillamp assembly.
6. Pull the bulb straight out from the socket.
7. Put a new bulb into the socket, insert it into the taillamp
assembly, and turn the bulb
socket clockwise until it clicks.
8. Reinstall the taillamp assembly and tighten the screws.
9. Reinstall the taillamp cover by snapping it into place.
License Plate Lamp
Passenger Side Shown, Driver
Side Similar

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Vehicle Care 313
1. Bulb Socket
2. Bulb
3. Lamp Assembly
To replace one of these bulbs:1. Push the lamp assembly (3) toward the center of the
vehicle.
2. Pull the lamp assembly down to remove.
3. Turn the bulb socket (1) counterclockwise to remove it
from the lamp assembly (3).
4. Pull the bulb (2) straight out of the bulb socket (1).
5. Push the replacement bulb straight into the bulb socket
and turn the bulb socket
clockwise to install it into the
lamp assembly.
6. Push the lamp assembly back into position until the release
tab locks into place.
Electrical System
Electrical System
Overload
The vehicle has fuses to protect
against an electrical system
overload. Fuses also protect power
devices in the vehicle.
Replace a bad fuse with a new one
of the identical size and rating.
If there is a problem on the road and
a fuse needs to be replaced, there
are some spare fuses and a fuse
puller in the left instrument panel
fuse block. The same amperage
fuse can also be borrowed. Choose
some feature of the vehicle that is
not needed to use and replace it as
soon as possible.
Headlamp Wiring
An electrical overload may cause
the lamps to go on and off, or in
some cases to remain off. Have the
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 and Circuit
Breakers
The wiring circuits in the vehicle are
protected from short circuits by a
combination of fuses and circuit
breakers. This greatly reduces the
chance of damage caused by
electrical problems.