Trailer Brakes
A loaded trailer that weighs more than 2,000 lbs(900 kg) needs to have its own brake system that isadequate for the weight of the trailer. Be sure to readand follow the instructions for the trailer brakes so theyare installed, adjusted and maintained properly.
Since the vehicle is equipped with StabiliTrak®, thetrailer brakes cannot tap into the vehicle's hydraulicsystem.
Driving with a Trailer
{WARNING:
When towing a trailer, exhaust gases may collect
at the rear of the vehicle and enter if the liftgate,
trunk/hatch, or rear-most window is open.
Engine exhaust contains carbon monoxide (CO)
which cannot be seen or smelled. It can cause
unconsciousness and even death.
To maximize safety when towing a trailer:
.Have the exhaust system inspected for
leaks and make necessary repairs before
starting a trip.
(Continued)
WARNING: (Continued)
.Never drive with the liftgate, trunk/hatch,
or rear-most window open.
.Fully open the air outlets on or under the
instrument panel.
.Adjust the Climate Control system to a setting
that brings in only outside air and set the fan
speed to the highest setting. See Climate
Control System in the Index.
For more information about carbon monoxide, see
Engine Exhaust on page 3!41.
Towing a trailer requires a certain amount ofexperience. The combination you are driving is longerand not as responsive as the vehicle itself. Getacquainted with the handling and braking of the rigbefore setting out for the open road.
Before starting, check all trailer hitch parts andattachments, safety chains, electrical connectors,lamps, tires and mirrors. If the trailer has electricbrakes, start the combination moving and then applythe trailer brake controller by hand to be sure thebrakes work.
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During the trip, check occasionally to be sure that theload is secure and the lamps and any trailer brakesstill work.
Following Distance
Stay at least twice as far behind the vehicle ahead asyou would when driving the vehicle without a trailer.This can help to avoid heavy braking and sudden turns.
Passing
More passing distance is needed when towing a trailer.The combination will not accelerate as quickly and islonger so it is necessary to go much farther beyond thepassed vehicle before returning to the lane.
Backing Up
Hold the bottom of the steering wheel with one hand.Then, to move the trailer to the left, move that hand tothe left. To move the trailer to the right, move your handto the right. Always back up slowly and, if possible,have someone guide you.
Making Turns
Notice:Making very sharp turns while traileringcould cause the trailer to come in contact with thevehicle. The vehicle could be damaged. Avoidmaking very sharp turns while trailering.
When turning with a trailer, make wider turns thannormal. Do this so the trailer will not strike softshoulders, curbs, road signs, trees or other objects.Avoid jerky or sudden maneuvers. Signal wellin advance.
If the trailer turn signal bulbs burn out, the arrowson the instrument panel will still flash for turns. It isimportant to check occasionally to be sure the trailerbulbs are still working.
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Driving On Grades
Reduce speed and shift to a lower gearbeforestartingdown a long or steep downgrade. If the transmission isnot shifted down, the brakes might get hot and nolonger work well.
Vehicles can tow in D (Drive). Shift the transmission toa lower gear if the transmission shifts too often underheavy loads and/or hilly conditions.
The tow/haul mode may be used if the transmissionshifts too often. SeeTow/Haul Mode on page 3!36.
When towing at high altitude on steep uphill grades,consider the following: Engine coolant will boil at alower temperature than at normal altitudes. If the engineis turned off immediately after towing at high altitude onsteep uphill grades, the vehicle may show signs similarto engine overheating. To avoid this, let the engine runwhile parked, preferably on level ground, with theautomatic transmission in P (Park) for a few minutesbefore turning the engine off. If the overheat warningcomes on, seeEngine Overheating on page 7!34.
Parking on Hills
{WARNING:
Parking the vehicle on a hill with the trailer
attached can be dangerous. If something goes
wrong, the rig could start to move. People can be
injured, and both the vehicle and the trailer can be
damaged. When possible, always park the rig on
a flat surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift intoP (Park) yet. Turn the wheels into the curb if facingdownhill or into traffic if facing uphill.
2. Have someone place chocks under the trailerwheels.
3. When the wheel chocks are in place, release theregular brakes until the chocks absorb the load.
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4. Reapply the brake pedal. Then apply the parkingbrake and shift into P (Park).
5. 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 not move, even
when on fairly level ground, always put the shift
lever fully in P (Park) with the parking brake
firmly set.
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 storethe chocks.
Maintenance When Trailer Towing
The vehicle needs service more often when pulling atrailer. See this manual's Maintenance Schedule orIndex for more information. Things that are especiallyimportant in trailer operation are automatic transmissionfluid, engine oil, axle lubricant, belts, cooling systemand brake system. It is a good idea to inspect thesebefore and during the trip.
Check periodically to see that all hitch nuts and boltsare tight.
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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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Electric Brake Control Wiring
Provisions
These wiring provisions are included with the vehicle aspart of the trailer wiring package. These provisions arefor an electric brake controller. The instrument panelcontains blunt cut wires near the data link connector forthe trailer brake controller. The harness contains thefollowing wires:
.Dark Blue: Brake Signal to Trailer Connector
.Red/Black: Battery
.Light Blue/White: Brake Switch
.White: Ground
It should be installed by your dealer/retailer or aqualified service center.
Trailer Recommendations
Subtract the hitch loads from the Cargo Weight Rating(CWR). CWR is the maximum weight of the load thevehicle can carry. It does not include the weight of thepeople inside, but you can figure about 150 lbs. (68 kg)for each passenger. The total cargo load must not bemore than the vehicles CWR.
Weigh the vehicle with the trailer attached, so theGVWR or GAWR are not exceeded. If using aweight-distributing hitch, weigh the vehicle without thespring bars in place.
The best performance is obtained by correctlyspreading out the weight of the load and choosing thecorrect hitch and trailer brakes.
For more information seeTowing a Traileronpage 6!42.
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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
Service
For service and parts needs, visit your dealer/retailer.You will receive genuine GM parts and GM-trained andsupported service people.
Genuine GM parts have one of these marks:
Accessories and Modifications
When non!dealer/non!retailer accessories are added tothe vehicle, they can affect vehicle performance andsafety, including such things as airbags, braking,stability, ride and handling, emissions systems,aerodynamics, durability, and electronic systems likeantilock brakes, traction control, and stability control.Some of these accessories could even causemalfunction or damage not covered by the vehiclewarranty.
Damage to vehicle components resulting from theinstallation or use of non!GM certified parts, includingcontrol module modifications, is not covered under theterms of the vehicle warranty and may affect remainingwarranty coverage for affected parts.
7-4