{WARNING:
Snow can trap engine exhaust under the vehicle.
This may cause exhaust gases to get inside.
Engine exhaust contains carbon monoxide (CO)
which cannot be seen or smelled. It can cause
unconsciousness and even death.
If the vehicle is stuck in the snow:
.Clear away snow from around the base of
your vehicle, especially any that is blocking
the exhaust pipe.
.Check again from time to time to be sure
snow does not collect there.
.Open a window about 5 cm (two inches) on
the side of the vehicle that is away from the
wind to bring in fresh air.
.Fully open the air outlets on or under the
instrument panel.
.Adjust the Climate Control system to a setting
that circulates the air inside the vehicle and
set the fan speed to the highest setting.
See Climate Control System in the Index.
(Continued)
WARNING: (Continued)
For more information about carbon monoxide, see
Engine Exhaust on page 3!41.
Snow can trap exhaust gases under your vehicle.
This can cause deadly CO (carbon monoxide) gas
to get inside. CO could overcome you and kill you.
You cannot see it or smell it, so you might not
know it is in your vehicle. Clear away snow from
around the base of your vehicle, especially any
that is blocking the exhaust.
Run the engine for short periods only as needed tokeep warm, but be careful.
To save fuel, run the engine for only short periods asneeded to warm the vehicle and then shut the engineoff and close the window most of the way to save heat.Repeat this until help arrives but only when you feelreally uncomfortable from the cold. Moving about tokeep warm also helps.
If it takes some time for help to arrive, now and thenwhen you run the engine, push the accelerator pedalslightly so the engine runs faster than the idle speed.This keeps the battery charged to restart the vehicleand to signal for help with the headlamps. Do this aslittle as possible to save fuel.
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Trailer Wiring Harness
Heavy-Duty Trailer Wiring Harness Package
The vehicle has a seven-pin universal heavy-duty trailerconnector attached to the rear bumper beam next to theintegrated trailer hitch.
The seven-wire harness contains the followingtrailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
*The fuses for these two circuits are installed in theunderhood electrical center, but the wires are notconnected. They should be connected by yourdealer/retailer or a qualified service center.
If charging a remote (non-vehicle) battery, press thetow/haul mode button located at the end of the shiftlever. This will boost the vehicle system voltage andproperly charge the battery. If the trailer is too light fortow/haul mode, turn on the headlamps as a second wayto boost the vehicle system and charge the battery.
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Section 7 Service and Appearance Care
Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4Accessories and Modifications . . . . . . . . . . . . . . . . . . 7-4California Proposition 65 Warning . . . . . . . . . . . . . . . 7-5California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5Doing Your Own Service Work . . . . . . . . . . . . . . . . . . 7-6Adding Equipment to the Outside of theVehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
Fuel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7Gasoline Octane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8Gasoline Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 7-8California Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9Fuel E85 (85% Ethanol) . . . . . . . . . . . . . . . . . . . . . . . . . 7-9Fuels in Foreign Countries . . . . . . . . . . . . . . . . . . . . . 7-10Filling the Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11Filling a Portable Fuel Container . . . . . . . . . . . . . . . 7-13
Checking Things Under the Hood. . . . . . . . . . . . . . . 7-14Hood Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15Engine Compartment Overview . . . . . . . . . . . . . . . . 7-16Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-17Engine Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 7-20Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . . 7-22
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . 7-24Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-28Engine Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-29Engine Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-34Overheated Engine ProtectionOperating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-37Engine Fan Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-37Power Steering Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 7-38Windshield Washer Fluid . . . . . . . . . . . . . . . . . . . . . . 7-39Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-40Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-43Jump Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-44
All-Wheel Drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-49
Rear Axle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-50
Front Axle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-51
Headlamp Aiming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-52
Bulb Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-54High Intensity Discharge (HID) Lighting . . . . . . . . 7-54LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-55Back-Up Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-55License Plate Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-56Replacement Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-56
7-1
Headlamp Aiming
The vehicle has a visual optical headlamp aimingsystem. The aim of the headlamps have been preset atthe factory and should need no further adjustment.
However, if the vehicle is damaged in a crash, the aimof the headlamps may be affected and adjustment maybe necessary.
If oncoming vehicles flash their high beams at you, thismay mean the vertical aim of your headlamps needs tobe adjusted.
It is recommended that the vehicle is taken to yourdealer/retailer for service if the headlamps need to beadjusted. It is possible however, to re-aim theheadlamps as described.
The vehicle should:
.Be placed so the headlamps are 25 ft. (7.6 m) froma light colored wall or other flat surface.
.Have all four tires on a level surface which is levelall the way to the wall or other flat surface.
.Be placed so it is perpendicular to the wall or otherflat surface.
.Not have any snow, ice, or mud on it.
.Be fully assembled and all other work stoppedwhile headlamp aiming is being performed.
.Be normally loaded with a full tank of fuel and oneperson or 160 lbs (75 kg) sitting on the driver seat.
.Have the tires properly inflated.
.Have the spare tire is in its proper location in thevehicle.
Headlamp aiming is done with the vehicle's low-beamheadlamps. The high-beam headlamps will be correctlyaimed if the low-beam headlamps are aimed properly.
To adjust the vertical aim:
1. Open the hood. SeeHood Releaseon page 7!15for more information.
2. Locate the center ofthe projector lens ofthe low!beamheadlamp.
3. Record the distance from the ground to the centerof the projector lens of the low!beam headlamp.
7-52
4. At a wall, measure from the ground upward (A) tothe recorded distance from Step 3 and mark it.
5. Draw or tape a horizontal line (B) on the wall thewidth of the vehicle at the height of the mark inStep 4.
Notice:Do not cover a headlamp to improve beamcut-off when aiming. Covering a headlamp maycause excessive heat build-up which may causedamage to the headlamp.
6. Turn on the low-beam headlamps and place apiece of cardboard or equivalent in front of theheadlamp not being adjusted. This allows only thebeam of light from the headlamp being adjusted tobe seen on the flat surface.
7. Locate the vertical headlamp aiming screws, whichare under the hood near each headlamp assembly.
The adjustment screw can be turned with aE8 Torx®socket.
8. Turn the vertical aiming screw until the headlampbeam is aimed to the horizontal tape line. Turn itclockwise or counterclockwise to raise or lower theangle of the beam.
7-53
9. Make sure that the light from the headlamp ispositioned at the bottom edge of the horizontaltape line. The lamp on the left (A) shows thecorrect headlamp aim. The lamp on the right (B)shows the incorrect headlamp aim.
10. Repeat Steps 7 through 9 for the oppositeheadlamp.
Bulb Replacement
For the proper type of replacement bulbs, seeReplacement Bulbs on page 7!56.
For any bulb changing procedure not listed in thissection, contact your dealer/retailer.
High Intensity Discharge (HID)
Lighting
{WARNING:
The low beam high intensity discharge 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/
retailer or a qualified technician service them.
The vehicle may have HID headlamps. After an HIDheadlamp bulb has been replaced, you may notice thatthe beam is a slightly different shade than it wasoriginally. This is normal.
7-54
LED Lighting
The vehicle may have LED headlamps. Forreplacement of the LED lighting assembly contactyour dealer/retailer.
Back-Up Lamps
To replace this bulb:
1. Open the liftgate. SeePower Liftgateonpage 3!14for moreinformation.
2. Remove the twoscrews from thetaillamp assembly.
3. Pull the taillamp assembly rearward until youdisengage the inner pins on the taillamp assemblyfrom the vehicle.
4. Press the release tab, if the bulb socket has one,and turn the socket counterclockwise to remove itfrom the taillamp assembly.
5. Pull the old bulb straight out from the socket.
6. Press a new bulb into the socket, insert the socketinto the taillamp assembly and turn the socketclockwise into the taillamp assembly until it clicks.
7-55
If you need to replace any of your wheels, wheel bolts,wheel nuts, or Tire Pressure Monitor System (TPMS)sensors, replace them only with new GM originalequipment parts. This way, you will be sure to havethe right wheel, wheel bolts, wheel nuts, and TPMSsensors for your vehicle.
{WARNING:
Using the wrong replacement wheels, wheel bolts,
or wheel nuts on your vehicle can be dangerous.
It could affect the braking and handling of your
vehicle, make your tires lose air and make you
lose control. You could have a collision in which
you or others could be injured. Always use the
correct wheel, wheel bolts, and wheel nuts for
replacement.
Notice:The wrong wheel can also cause problemswith bearing life, brake cooling, speedometer orodometer calibration, headlamp aim, bumper height,vehicle ground clearance, and tire or tire chainclearance to the body and chassis.
SeeChanging a Flat Tireon page 7!80for moreinformation.
Used Replacement Wheels
{WARNING:
Putting a used wheel on the vehicle is dangerous.
You cannot know how it has been used or how
far it has been driven. It could fail suddenly and
cause a crash. If you have to replace a wheel,
use a new GM original equipment wheel.
Tire Chains
{WARNING:
Do not use tire chains. There is not enough
clearance. Tire chains used on a vehicle without
the proper amount of clearance can cause
damage to the brakes, suspension, or other
vehicle parts. The area damaged by the tire
chains could cause you to lose control of the
vehicle and you or others may be injured in a
crash. Use another type of traction device only if
its manufacturer recommends it for use on the
(Continued)
7-78