2007 GMC YUKON XL fuel cap

If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully
install the cap. SeeFilling the Tank on page 432.
The diagnostic system can determine if the
fuel cap has been left off or improperly installed.
A loose or missing fuel cap will allow fuel to
evaporate into the atmosphere. A few driving trips
with the cap properly installed should turn the
light off.
Did you just drive through a deep puddle of
water?
If so, your electrical system may be wet. The
condition will usually be corrected when the
electrical system dries out. A few driving trips
should turn the light off.Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel.
SeeGasoline Octane on page 428. Poor fuel
quality will cause your engine not to run as
efficiently as designed. You may notice this as
stalling after start-up, stalling when you put
the vehicle into gear, misring, hesitation on
acceleration, or stumbling on acceleration.
(These conditions may go away once the engine
is warmed up.) This will be detected by the
system and cause the light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at
least one full tank of the proper fuel to turn the
light off.
If none of the above steps have made the light
turn off, your dealer can check the vehicle.
Your dealer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that may have developed.
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Fuel Gage
The fuel gage, when the ignition is on, tells you
about how much fuel you have left in your tank.
The gage will rst indicate empty before you
are out of fuel, and you should get more fuel as
soon as possible.
When the fuel tank is low, the FUEL LEVEL LOW
message will appear. SeeDIC Warnings and
Messages on page 254.
Here are some situations you may experience with
your fuel gage. None of these indicate a problem
with the fuel gage.
At the gas station, the fuel pump shuts off
before the gage reads full.
It takes a little more or less fuel to ll up than
the fuel gage indicated. For example, the
gage may have indicated the tank was half full,
but it actually took a little more or less than
half the tank’s capacity to ll the tank.
The gage goes back to empty when you turn
off the ignition.
Low Fuel Warning Light
This light, under the fuel
gage, will come on
briey when you
are starting the engine.
This light and a chime will come on when the fuel
tank is low on fuel. There will also be a “FUEL
LEVEL LOW” message on the Driver Information
Center, seeDIC Warnings and Messages on
page 254for more information. When you add fuel
this light and message should go off. If it does
not, have your vehicle serviced.United StatesCanada
243

TIGHTEN GAS CAP
If the vehicle’s fuel cap is not tightened properly,
this message may display along with the check
engine light on the instrument panel cluster.
SeeMalfunction Indicator Lamp on page 236.
Reinstall the fuel cap fully. SeeFilling the Tank on
page 432. The diagnostic system can determine
if the fuel cap has been left off or improperly
installed. A loose or missing fuel cap will allow fuel
to evaporate into the atmosphere. A few driving
trips with the cap properly installed should turn this
light and message off.
TIRE LEARNING ACTIVE
If your vehicle has a Tire Pressure Monitor (TPM)
system, this message will display when the system
is re-learning the tire positions on your vehicle. See
DIC Operation and Displays (With DIC Buttons) on
page 244orDIC Operation and Displays (Without
DIC Buttons) on page 251for more information.
The tire positions must be re-learned after rotating
the tires or after replacing a tire or sensor. SeeTire
Inspection and Rotation on page 497,Tire Pressure
Monitor System on page 492, andInation - Tire
Pressure on page 490for more information.
TRACTION CONTROL OFF
If your vehicle has StabiliTrak®, this message will
display when the traction control system is
turned off. Adjust your driving accordingly.
SeeStabiliTrak
®System on page 348for more
information.
TRANSMISSION HOT IDLE ENGINE
Notice:If you drive your vehicle while
the transmission uid 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 your warranty. Do not drive your
vehicle with overheated transmission uid
or while the transmission temperature warning
is displayed.
If the transmission uid in the vehicle gets hot, this
message will display along with a continuous
chime. Driving with the transmission uid
temperature high can cause damage to the vehicle.
Stop the vehicle and let it idle to allow the
transmission to cool. This message will clear and
the chime will stop when the uid temperature
reaches a safe level.
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Certication/Tire Label
A vehicle specic Certication/Tire label is found
on the rear edge of the driver’s door. The
label shows the size of your vehicle’s original tires
and the ination pressures needed to obtain the
gross weight capacity of your vehicle. This is called
Gross Vehicle Weight Rating (GVWR). The
GVWR includes the weight of the vehicle, all
occupants, fuel, and cargo.
The Certication/Tire label also tells you the
maximum weights for the front and rear axles,
called Gross Axle Weight Rating (GAWR).To nd out the actual loads on your front and rear
axles, you need to go to a weigh station and
weigh your vehicle. Your dealer can help you with
this. Be sure to spread out your load equally on
both sides of the centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
The Certication/Tire label also contains
information about your Front Axle Reserve
Capacity.
And, if you do have a heavy load, you should
spread it out.{CAUTION:
Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (GAWR). If you do,
parts on your vehicle can break, and it
can change the way your vehicle handles.
These could cause you to lose control
and crash. Also, overloading can shorten
the life of your vehicle.
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Here are some guidelines for safely carrying a
snow plow on your vehicle:
Make sure the weight on the front and rear
axles does not exceed the axle rating
for each.
For the front axle, if more cargo or passengers
must be carried, appropriate counter ballast
must be installed rear of the rear axle. Counter
ballast must be properly secured so it will
not move during driving.
Follow the snow plow manufacturer’s
recommendations regarding rear ballast. Rear
ballast may be required to ensure a proper
front and rear weight distribution ratio,
even though the actual weight at the front axle
may be less than the front axle rating.
The snow plow manufacturer or installer can
assist you in determining the amount of rear
ballast required, to help make sure your
snowplow/vehicle combination does not
exceed the GVW rating, the front and rear
axle ratings, and the front and rear weight
distribution ratio.
The total vehicle must not exceed the GVW
rating.
Q:What is front axle reserve capacity, and
how do I calculate it?
A:Front axle reserve capacity is the difference
between your front gross axle weight rating
(GAWR) and the front axle weight of your
vehicle with full fuel and passengers. Basically,
it is the amount of weight you can add to
your front axle before reaching your
front GAWR.
The front axle reserve capacity for your vehicle
can be found in the lower right corner of the
Certication/Tire label, as shown.
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397

Q:What is total vehicle reserve capacity?
A:This is the difference between your GVWR and
the weight of your vehicle with full fuel and
passengers. It is the amount of weight you can
add to your vehicle before reaching your
GVWR. Keep in mind that reserve capacity
numbers are intended as a guide when
selecting the amount of equipment or cargo
your vehicle can carry. If you are unsure
of your vehicle’s front, rear, or total weight, go
to a weigh station and weigh your vehicle.
Your dealer can also help you with this.
The total vehicle reserve capacity for your
vehicle can be found in the lower right corner
of the Certication/Tire label as shown
previously.
See your dealer for additional advice and
information about using a snow plow on your
vehicle. Also, seeLoading Your Vehicle on
page 390.
Emergency Roof Lamp Provisions
Vehicles with the RPO VYU snow plow prep
package also have an emergency roof lamp
provision package, RPO TRW. Wiring for the
emergency roof lamp is provided above the
overhead console. SeeAuxiliary Roof Mounted
Lamp on page 203for switch location.
Towing
Towing Your Vehicle
Consult your dealer or a professional towing
service if you need to have your disabled vehicle
towed. SeeRoadside Assistance Program on
page 577.
If you want to tow your vehicle behind another
vehicle for recreational purposes (such as behind
a motorhome), see “Recreational Vehicle
Towing” following.
400

Service.........................................................426
Accessories and Modications....................426
California Proposition 65 Warning...............427
Doing Your Own Service Work...................427
Adding Equipment to the Outside of
Your Vehicle...........................................428
Fuel..............................................................428
Gasoline Octane........................................428
Gasoline Specications...............................428
California Fuel............................................429
Additives....................................................429
Fuel E85 (85% Ethanol).............................430
Fuels in Foreign Countries.........................431
Filling the Tank..........................................432
Filling a Portable Fuel Container................434
Checking Things Under the Hood..............434
Hood Release............................................435
Engine Compartment Overview...................436
Engine Oil..................................................438
Engine Oil Life System...............................441
Engine Air Cleaner/Filter.............................443
Automatic Transmission Fluid.....................445
Engine Coolant...........................................449Coolant Surge Tank Pressure Cap.............451
Engine Overheating....................................452
Overheated Engine Protection
Operating Mode......................................454
Cooling System..........................................455
Engine Fan Noise......................................460
Power Steering Fluid..................................461
Windshield Washer Fluid............................462
Brakes.......................................................463
Battery.......................................................466
Jump Starting.............................................467
Rear Axle.....................................................472
Four-Wheel Drive.........................................473
Front Axle....................................................474
Headlamp Aiming........................................475
Bulb Replacement........................................478
Halogen Bulbs............................................478
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps.......................................478
License Plate Lamp....................................480
Replacement Bulbs....................................481
Section 5 Service and Appearance Care
423

Those stations that do have E85 should have a
label indicating ethanol content. Do not use the fuel
if the ethanol content isgreaterthan 85%.
At a minimum, E85 should meet ASTM
Specication D 5798.
To ensure quick starts in the wintertime, the
E85 fuel must be formulated properly for your
climate according to ASTM specication D 5798.
If you have trouble starting on E85, it may be
because your E85 fuel is not properly formulated
for your climate. If this happens, switching to
gasoline or adding gasoline to your fuel tank may
improve starting. For good starting and heater
efficiency below 32°F (0°C), the fuel mix in the fuel
tank should contain no more than 70% ethanol.
It is best not to alternate repeatedly between
gasoline and E85. If you do switch fuels, it is
recommended that you add as much fuel as
possible — do not add less than ve gallons
(18.9 L) when refueling. You should drive the
vehicle immediately after refueling for at least
ve miles (8 km).
E85 has less energy per gallon than gasoline, so
you will need to rell your fuel tank more often
when using E85 than when you are using gasoline.
Regular unleaded gasoline is recommendedwhen pulling a trailer. For payload capacity with
ethanol fuel, seeLoading Your Vehicle on
page 390.
Notice:Some additives are not compatible
with E85 fuel and may harm your fuel system.
Damage caused by additives would not be
covered by your new vehicle warranty. Do not
use additives with E85 fuel.
Notice:Your vehicle was not designed for
fuel that contains methanol. Do not use
fuel containing methanol. It can corrode metal
parts in your fuel system and also damage
the plastic and rubber parts. That damage
would not be covered under your warranty.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be
hard to nd. Never use leaded gasoline or any other
fuel not recommended in the previous text on fuel.
Costly repairs caused by use of improper fuel would
not be covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business
in the country where you will be driving.
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