2008 PONTIAC GRAND PRIX Owners Manual

Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important weight
to measure because it affects the total or gross weight
of the vehicle. The Gross Vehicle Weight (GVW)
includes the curb weight of the vehicle, any cargo
in it, and the people who will be riding in the vehicle.
If there are a lot of options, equipment, passengers
and cargo in the vehicle, it will reduce the tongue
weight the vehicle can carry, which will also reduce
the trailer weight the vehicle can tow. And if towing
a trailer, the tongue load must be added to the GVW
because the vehicle will be carrying that weight, too.
SeeLoading Your Vehicle on page 4-22for more
information about your vehicle’s maximum load
capacity.When using a weight-carrying hitch or a
weight-distributing hitch, the trailer tongue (A)
should weigh 10 to 15 percent of the total loaded
trailer weight (B).
After the trailer is loaded, weigh the trailer and then
the tongue, separately, to see if the weights are
proper. The correct weight could be achieved simply
by moving some items around in the trailer.
4-31

Total Weight on Your Vehicle’s Tires
Be sure the vehicle’s tires are inated to the upper
limit for cold tires. These numbers can be found on
the Tire and Loading Information label, that is located
on the driver’s side center B-pillar. SeeLoading
Your Vehicle on page 4-22. Be sure not to go over
the GVW limit for the vehicle, or the GAWR, including
the weight of the trailer tongue. If a weight distribution
hitch is used, make sure not to go over the rear axle limit
before applying the weight distribution spring bars.
Hitches
It is important to have the correct hitch equipment.
Crosswinds, large trucks going by, and rough roads
are a few reasons why the correct hitch is needed.
Here are some rules to follow:
The rear bumper on the vehicle is not intended
for hitches. Do not attach rental hitches or
other bumper-type hitches to it. Use only a
frame-mounted hitch that does not attach
to the bumper.
If any holes need to be made in the body of the
vehicle to install a trailer hitch, then be sure to
seal the holes later when the hitch is removed.
If the holes are not sealed, deadly carbon monoxide
(CO) from the exhaust can get into the vehicle.
SeeEngine Exhaust on page 2-36. Dirt and
water can, too.
Safety Chains
Always attach chains between the vehicle and the
trailer. Cross the safety chains under the tongue of the
trailer so that the tongue will not drop to the road if
it becomes separated from the hitch. Instructions about
safety chains may be provided by the hitch manufacturer
or by the trailer manufacturer. Follow the manufacturer’s
recommendation for attaching safety chains and do
not attach them to the bumper. Always leave just
enough slack so the rig can be turned around. And,
never allow safety chains to drag on the ground.
4-32

Trailer Brakes
Does your trailer have its own brakes? Be sure to read
and follow the instructions for the trailer brakes so
you’ll be able to install, adjust and maintain them
properly.
If your vehicle has anti-lock brakes, do not try to
tap into your vehicle’s brake system. If you do,
both brake systems won’t work well, or at all.
Even if your vehicle doesn’t have anti-lock brakes,
don’t tap into your vehicle’s brake system if the
trailer’s brake system will use more than
0.02 cubic inch (0.3 cc) of uid from your vehicle’s
master cylinder. If it does, both braking systems
won’t work well. You could even lose your brakes.
Will the trailer brake parts take 3,000 psi
(20 650 kPa) of pressure? If not, the trailer brake
system must not be used with your vehicle.
If everything checks out this far, then make the
brake uid tap at the upper rear master cylinder
port. But don’t use copper tubing for this. If you do,
it will bend and break off. Use steel brake tubing.
Driving with a Trailer
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, get to know the rig.
Acquaint yourself with the feel of handling and braking
with the added weight of the trailer. And always keep in
mind that the vehicle is now a good deal longer and not
nearly as responsive as the vehicle is by itself.
Before starting, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires, and mirror adjustment. If the trailer has
electric brakes, start the vehicle and trailer moving
and then apply the trailer brake controller by hand to
be sure the brakes are working. This lets you check
the electrical connection at the same time.
During your trip, check occasionally to be sure that
the load is secure, and that the lamps and any
trailer brakes are still working.
4-33

Following Distance
Stay at least twice as far behind the vehicle ahead as
when driving the vehicle without a trailer. This can
prevent situations that require heavy braking and
sudden turns.
Passing
More passing distance is needed up ahead when
towing a trailer. And, because the vehicle and trailer are
a good deal longer, distances between any vehicles
that are passed must be greater, before returning to
the proper lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, move that hand
to the left. To move the trailer to the right, move
that hand to the right. Always back up slowly and,
if possible, have someone guide you.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When turning with a trailer, make wider turns than
normal. Do this so the trailer will not strike soft
shoulders, curbs, road signs, trees, or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
Turn Signals When Towing a Trailer
When towing a trailer, the vehicle may need a different
turn signal asher and/or extra wiring. Check with
your dealer/retailer. The arrows on the instrument panel
will ash whenever signaling a turn or lane change.
Properly hooked up, the trailer lamps will also ash,
telling other drivers the vehicle and trailer are about to
turn, change lanes, or stop.
When towing a trailer, the arrows on the instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. You may think drivers behind you
are seeing the turn signal when they are not. It is
important to check occasionally to be sure the trailer
bulbs are still working.
4-34

The vehicle has bulb warning lights. When a trailer
lighting system is plugged into the vehicle’s lighting
system, its bulb warning lights may not indicate if one of
the lamps goes out. So, when a trailer lighting system
is plugged in, be sure to check the vehicle and
trailer lamps from time to time to be sure they are all
working. Once the trailer lamps have been disconnected,
the bulb warning lights can once again indicate if one
of the vehicle lamps is out.
Driving On Grades
Reduce speed and shift to a lower gear before starting
down a long or steep downgrade. If the vehicle is
not shifted down, the brakes may have to be used so
much that they would get hot and no longer work well.
On a long uphill grade, shift down and reduce the
vehicle’s speed to around 45 mph (70 km/h) to reduce
the possibility of engine and transmission overheating.
If the vehicle has overdrive, it may be driven in
THIRD (3) instead of DRIVE (D).
Parking on Hills
{CAUTION:
You really should not park your vehicle, with
a trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if the rig ever has to be parked on a hill, here is
how to do it:
1. Apply the regular brakes, but do not shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply the
parking brake, and then shift to PARK (P).
5. Release the regular brakes.
4-35

When You Are Ready to Leave After
Parking on a Hill
1. Apply the regular brakes and hold the pedal
down while you:
Start the engine
Shift into a gear
Release the parking brake
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store
the chocks.
Maintenance When Trailer Towing
The vehicle will need service more often when it
pulls a trailer. SeeScheduled Maintenance on page 6-4
for more information. Things that are especially
important in trailer operation are automatic transmission
uid, which should not be overlled, engine oil, drive
belts, cooling, and brake systems. Each of these
is covered in this manual, and the Index will help locate
them quickly. If trailering, it is a good idea to review
this information before starting on a trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily overheat during
severe operating conditions. SeeEngine Overheating
on page 5-27.
4-36

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-3
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-22
Engine Coolant.............................................5-24
Pressure Cap...............................................5-27
Engine Overheating.......................................5-27Overheated Engine Protection
Operating Mode........................................5-29
Cooling System............................................5-30
Power Steering Fluid.....................................5-39
Windshield Washer Fluid................................5-40
Brakes........................................................5-41
Battery........................................................5-45
Jump Starting...............................................5-46
Headlamp Aiming...........................................5-51
Bulb Replacement..........................................5-54
Halogen Bulbs..............................................5-54
Headlamps and Sidemarker Lamps.................5-54
Front Turn Signal, Parking and Fog Lamps......5-57
Taillamps, Turn Signal, and Stoplamps............5-58
Back-Up Lamps............................................5-59
License Plate Lamp......................................5-60
Replacement Bulbs.......................................5-60
Windshield Replacement.................................5-61
Windshield Wiper Blade Replacement..............5-61
Tires..............................................................5-62
Tire Sidewall Labeling...................................5-63
Tire Terminology and Denitions.....................5-66
Ination - Tire Pressure.................................5-69
Tire Pressure Monitor System.........................5-71
Section 5 Service and Appearance Care
5-1

Tire Pressure Monitor Operation.....................5-72
Tire Inspection and Rotation...........................5-75
When It Is Time for New Tires.......................5-77
Buying New Tires.........................................5-78
Different Size Tires and Wheels......................5-80
Uniform Tire Quality Grading..........................5-80
Wheel Alignment and Tire Balance..................5-82
Wheel Replacement......................................5-82
Tire Chains..................................................5-84
If a Tire Goes Flat........................................5-85
Tire Sealant and Compressor Kit (GXP)...........5-86
Changing a Flat Tire.....................................5-96
Removing the Spare Tire and Tools................5-98
Removing the Flat Tire and Installing the
Spare Tire..............................................5-100
Storing a Flat or Spare Tire and Tools...........5-107
Compact Spare Tire....................................5-109
Appearance Care..........................................5-109
Interior Cleaning.........................................5-109
Fabric/Carpet..............................................5-111
Leather......................................................5-112
Ultra Lux Suede..........................................5-113
Instrument Panel, Vinyl, and Other Plastic
Surfaces.................................................5-113
Care of Safety Belts....................................5-114Weatherstrips.............................................5-114
Washing Your Vehicle..................................5-114
Cleaning Exterior Lamps/Lenses....................5-115
Finish Care................................................5-115
Windshield and Wiper Blades.......................5-116
Aluminum Wheels.......................................5-116
Tires.........................................................5-117
Sheet Metal Damage...................................5-117
Finish Damage...........................................5-117
Underbody Maintenance...............................5-117
Chemical Paint Spotting...............................5-118
Vehicle Care/Appearance Materials................5-118
Vehicle Identication.....................................5-119
Vehicle Identication Number (VIN)................5-119
Service Parts Identication Label...................5-120
Electrical System..........................................5-120
Add-On Electrical Equipment.........................5-120
Headlamp Wiring........................................5-120
Windshield Wiper Fuses...............................5-121
Power Windows and Other Power Options......5-121
Fuses and Circuit Breakers..........................5-121
Instrument Panel Fuse Block........................5-122
Underhood Fuse Block................................5-124
Capacities and Specications........................5-128
Section 5 Service and Appearance Care
5-2