Maintenance When Trailer Towing
The vehicle needs service more often when pulling a
trailer. See this manual's Maintenance Schedule or
Index for more information. 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.
Trailer Wiring Harness
Heavy-Duty Trailer Wiring Harness Package
The vehicle has a seven-pin universal heavy-duty trailer
connector attached to the rear bumper beam next to the
integrated trailer hitch.The seven-wire harness contains the following
trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red w/ Black Stripe: Battery Feed*
.Dark Blue: Trailer Brake*
*The fuses for these two circuits are installed in the
underhood electrical center, but the wires are not
connected. They should be connected by your
dealer/retailer or a qualified service center.
If charging a remote (non-vehicle) battery, press the
tow/haul mode button located at the end of the shift
lever. This will boost the vehicle system voltage and
properly charge the battery. If the trailer is too light for
tow/haul mode, turn on the headlamps as a second way
to boost the vehicle system and charge the battery.
6-53
Section 7 Service and Appearance Care
Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Accessories and Modifications . . . . . . . . . . . . . . . . . . 7-4
California Proposition 65 Warning . . . . . . . . . . . . . . . 7-5
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
Doing Your Own Service Work . . . . . . . . . . . . . . . . . . 7-5
Adding Equipment to the Outside of the Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
Gasoline Octane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
Gasoline Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
California Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
Fuel E85 (85% Ethanol) . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Fuels in Foreign Countries . . . . . . . . . . . . . . . . . . . . . . 7-9
Filling the Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10
Filling a Portable Fuel Container . . . . . . . . . . . . . . . 7-12
Checking Things Under the Hood . . . . . . . . . . . . . . .7-12
Hood Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13
Engine Compartment Overview . . . . . . . . . . . . . . . . 7-14
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
Engine Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 7-18
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . . 7-20 Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . 7-22
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-26
Engine Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-27
Engine Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-33
Overheated Engine Protection
Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-35
Engine Fan Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-35
Power Steering Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 7-36
Windshield Washer Fluid . . . . . . . . . . . . . . . . . . . . . . 7-37
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-38
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-41
Jump Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-42
All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-47
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-48
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-49
Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-50
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-53
High Intensity Discharge (HID) Lighting . . . . . . . . 7-53
Taillamps, Turn Signal, Sidemarker, Stoplamps and Back-up Lamps . . . . . . . . . . . . . . . . . . . . . . . . . 7-53
License Plate Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-55
Replacement Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-55
7-1
experiences problems due to dirty injectors or valves,
look for gasoline that is advertised as TOP TIER
Detergent Gasoline.
For customers who do not use TOP TIER Detergent
Gasoline regularly, one bottle of GM Fuel System
Treatment PLUS, added to the fuel tank at every engine
oil change, can help clean deposits from fuel injectors
and intake valves. GM Fuel System Treatment PLUS is
the only gasoline additive recommended by General
Motors.
Also, your dealer/retailer has additives that will help
correct and prevent most deposit‐related problems.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines might be available
in your area. We recommend that you use these
gasolines, if they comply with the specifications
described earlier. However, E85 (85% ethanol) and
other fuels containing more than 10% ethanol must not
be used in vehicles that were not designed for those
fuels.
Notice:This vehicle was not designed for fuel that
contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in the fuel
system and also damage plastic and rubber parts.
That damage would not be covered under the
vehicle warranty. Some gasolines that are not reformulated for low
emissions can contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. We recommend against
the use of such gasolines. Fuels containing MMT can
reduce the life of spark plugs and the performance of
the emission control system could be affected. The
malfunction indicator lamp might turn on. If this occurs,
return to your dealer/retailer for service.
Fuel E85 (85% Ethanol)
This vehicle can use either unleaded gasoline or
85% ethanol fuel (E85). We encourage the use of
E85 in vehicles that are designed to use it. The ethanol
in E85 is a
“renewable” fuel, meaning it is made from
renewable sources such as corn and other crops.
Many service stations will not have an 85% ethanol
fuel (E85) pump available. The U.S. Department
of Energy has an alternative fuels website
(www.eere.energy.gov/afdc/infrastructure/locator.html)
that can help you find E85 fuel. Those stations that do
have E85 should have a label indicating ethanol
content. Do not use the fuel if the ethanol content is
greater than 85%.
7-8
Filling a Portable Fuel Container
{WARNING:
Never fill a portable fuel container while it is in the
vehicle. Static electricity discharge from the
container can ignite the fuel vapor. You can be
badly burned and the vehicle damaged if this
occurs. To help avoid injury to you and others:
.Dispense fuel only into approved containers.
.Do not fill a container while it is inside a
vehicle, in a vehicle's trunk, pickup bed, or on
any surface other than the ground.
.Bring the fill nozzle in contact with the inside
of the fill opening before operating the nozzle.
Contact should be maintained until the filling is
complete.
.Do not smoke while pumping fuel.
.Do not use a cellular phone while
pumping fuel.
Checking Things Under
the Hood
{WARNING:
An electric fan under the hood can start up and
injure you even when the engine is not running.
Keep hands, clothing, and tools away from any
underhood electric fan.
{WARNING:
Things that burn can get on hot engine parts and
start a fire. These include liquids like fuel, oil,
coolant, brake fluid, windshield washer and other
fluids, and plastic or rubber. You or others could
be burned. Be careful not to drop or spill things
that will burn onto a hot engine.
7-12
A.Engine Air Cleaner/Filter on page 7‑20.
B. Coolant Surge Tank and Pressure Cap. See Cooling System on page 7‑26.
C. Remote Positive (+) Terminal. See Jump Starting
on page 7‑42.
D. Battery on page 7‑41.
E. Engine Oil Fill Cap. See “When to Add Engine Oil”
under Engine Oil on page 7‑15.
F. Automatic Transmission Dipstick (Out of View). See “Checking the Fluid Level” underAutomatic
Transmission Fluid on page 7‑22.
G. Remote Negative (−) Terminal (GND) (Out of View). See Jump Starting on page 7‑42.
H. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 7‑15.
I. Engine Cooling Fan (Out of View). See Cooling
System on page 7‑26.
J. Power Steering Fluid Reservoir (Out of View). See Power Steering Fluid on page 7‑36.
K. Brake Master Cylinder Reservoir. See “Brake
Fluid” under Brakes on page 7‑38.
L. Underhood Fuse Block on page 7‑108.
M. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on
page 7‑37.
Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil level at each
fuel fill. In order to get an accurate reading, the oil must
be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop. See
Engine Compartment Overview
on page 7‑14for the
location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes to drain back into the oil pan. If this is not done, the
oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
7-15
When to Add Engine Oil
If the oil is below the cross-hatched area at the tip
of the dipstick, add at least one quart/liter of the
recommended oil. This section explains what kind of
oil to use. For engine oil crankcase capacity, see
Capacities and Specifications on page 7‑112.
Notice:Do not add too much oil. If the engine has
so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, the engine could be damaged.
See Engine Compartment
Overviewon page 7‑14for the location of the
engine oil fill cap.
Add enough oil to put the level somewhere in the proper
operating range. Push the dipstick all the way back in
when through.
7-16
What Kind of Engine Oil to Use
Look for three things:
.GM4718M
This vehicle's engine requires a special oil
meeting GM Standard GM4718M. Oils meeting
this standard may be identified as synthetic.
However, not all synthetic oils will meet this
GM standard. Use only an oil that meets GM
Standard GM4718M.
Notice: Using oils that do not have the GM4718M
Standard designation can cause engine damage not
covered by the vehicle warranty.
.SAE 5W-30
SAE 5W-30 is best for the vehicle. These
numbers on an oil container show its viscosity,
or thickness. Do not use other viscosity oils
such as SAE 20W-50.
.American Petroleum Institute (API) starburst
symbol
Oils meeting these
requirements should have
the starburst symbol on
the container. This symbol
indicates that the oil has
been certified by the
American Petroleum
Institute (API).
This vehicle's engine was filled at the factory with a
Mobil 1
®synthetic oil meeting all requirements for this
vehicle.
Substitute Engine Oil: When adding oil to maintain
engine oil level, oil meeting GM Standard GM4718M
might not be available. You can add substitute oil
designated SAE 5W-30 with the starburst symbol
at all temperatures. Substitute oil not meeting
GM Standard GM4718M should not be used for an
oil change.
7-17
Engine Oil Additives / Engine Oil
Flushes
Do not add anything to the oil. The recommended oils
with the starburst symbol that meet GM standards are
all that is needed for good performance and engine
protection.
Engine oil system flushes are not recommended and
could cause engine damage not covered by the vehicle
warranty.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that indicates when
to change the engine oil and filter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change is indicated can vary considerably.
For the oil life system to work properly, the system must
be reset every time the oil is changed.When the system has calculated that oil life has been
diminished, it indicates that an oil change is necessary.
A CHANGE ENGINE OIL SOON message comes on.
See
DIC Warnings and Messages
on page 4‑48.
Change the oil as soon as possible within the next
600 miles (1 000 km). It is possible that, if driving under
the best conditions, the oil life system might not indicate
that an oil change is necessary for over a year.
However, the engine oil and filter must be changed at
least once a year and at this time the system must be
reset. Your dealer/retailer has trained service people
who will perform this work using genuine parts and
reset the system. It is also important to check the oil
regularly and keep it at the proper level.
If the system is ever reset accidentally, the oil must be
changed at 3,000 miles (5 000 km) since the last oil
change. Remember to reset the oil life system
whenever the oil is changed.
7-18