2007 CHEVROLET EXPRESS PASSANGER engine

If you’ll be pulling a trailer that, when loaded, will
weigh more than 5,000 lbs (2 270 kg), be sure
to use a properly mounted weight-distributing hitch
and sway control of the proper size. This
equipment is very important for proper vehicle
loading and good handling when you’re driving.
You should always use a sway control if your
trailer will weigh more than these limits. You can
ask a hitch dealer/retailer about sway controls.
Will you have to make any holes in the body
of your vehicle when you install a trailer hitch?
If you’re using the wiring provided with the
factory-installed trailering package, you should not
need to make any holes in the body of your vehicle.
However, if you have an aftermarket hitch installed,
you may need to make holes in the body.
If you do, then be sure to seal the holes later
when you remove the hitch. If you don’t seal them,
deadly carbon monoxide (CO) from your exhaust
can get into your vehicle as well as dirt and water.
See “Carbon Monoxide” underEngine Exhaust
on page 132.Safety Chains
You should always attach chains between your
vehicle and your trailer. Cross the safety
chains under the tongue of the trailer to help
prevent the tongue from contacting 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
you can turn with your rig. Never allow safety
chains to drag on the ground.
Trailer Brakes
If your trailer weighs more than 1,000 lbs (450 kg)
loaded, then it needs its own brakes – and they
must be adequate. 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 StabiliTrak
®, your trailer
brake system cannot tap into the vehicle’s
hydraulic brake system.
281

Driving with a Trailer
{CAUTION:
If you have a rear-most window open and
you pull a trailer with your vehicle, carbon
monoxide (CO) could come into your
vehicle. You can not see or smell CO. It
can cause unconsciousness or death. See
Engine Exhaust on page 132. To maximize
your safety when towing a trailer:
Have your exhaust system inspected
for leaks, and make necessary repairs
before starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with
the fan on any speed. This will bring
fresh, outside air into your vehicle.
CAUTION: (Continued)
CAUTION: (Continued)
Do not use the climate control
setting for maximum air because it
only recirculates the air inside your
vehicle. See Climate Control System
in the Index.
Towing a trailer requires a certain amount of
experience. Before setting out for the open road,
you’ll want to get to know your 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 you are driving is
now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer
moving and then apply the trailer brake controller
by hand to be sure the brakes are working.
This lets you check your electrical connection at
the same time.
282

Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle has to have
extra wiring and a heavy-duty turn signal
flasher (included in the optional trailering package).
The arrows on your instrument panel will flash
whenever you signal a turn or lane change.
Properly hooked up, the trailer lamps will also
flash, telling other drivers you’re about to
turn, change lanes or stop.
When towing a trailer, the arrows on your
instrument panel will flash for turns even if the bulbs
on the trailer are burned out. Thus, you may think
drivers behind you are seeing your signal when
they are not. It’s important to check occasionally to
be sure the trailer bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbefore
you start down a long or steep downgrade. If you
don’t shift down, you might have to use your
brakes so much that they would get hot and no
longer work well.
You can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or a lower gear
under heavy loads and/or hilly conditions.
When towing at high altitude on steep uphill
grades, consider the following: Engine coolant will
boil at a lower temperature than at normal
altitudes. If you turn your engine off immediately
after towing at high altitude on steep uphill grades,
your vehicle may show signs similar to engine
overheating. To avoid this, let the engine run while
parked (preferably on level ground) with the
automatic transmission in PARK (P) for a few
minutes before turning the engine off. If you do get
the overheat warning, seeEngine Overheating
on page 315.
284

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 you ever have to park your rig on a hill,
here’s how to do it:
1. Apply your regular brakes, but don’t shift
into PARK (P) yet. Then turn your wheels
into the curb if facing downhill or into traffic
if facing uphill.
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 your
parking brake and then shift to PARK (P).
5. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal
down while you:
•start your engine,
•shift into a gear, and
•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.
285

Maintenance When Trailer Towing
Your vehicle will need service more often when
you’re pulling a trailer. See the Maintenance
Schedule for more on this. Things that are
especially important in trailer operation are
automatic transmission fluid (don’t overfill), engine
oil, axle lubricant, belt, cooling system and
brake system. Each of these is covered in this
manual, and the Index will help you find them
quickly. If you’re trailering, it’s a good idea
to review these sections before you start your trip.
Check periodically to see that all hitch nuts and
bolts are tight.
Trailer Wiring Harness
The optional heavy-duty trailer wiring package
includes a seven-wire harness assembly at the rear
of the vehicle and a four-wire harness assembly
under the left hand side of the instrument panel.
The seven-wire harness assembly is taped together
and located in a frame pocket at the driver side rear
left corner of the frame. The seven-wire harness
includes a 30-amp feed wire.Both harnesses come without connectors and
should be wired by a qualified electrical technician.
The technician can use the following color code
chart when connecting the wiring harness to your
trailer and trailer brake controller.
Seven-Wire Harness
•Light Green: Back-up lamps
•Brown: Parking lamps
•Yellow: Left stoplamp and turn signal
•Dark Green: Right stoplamp and turn signal
•Dark Blue: Use for electric trailer brakes
•Red/Black Stripe: Trailer accessory
•White (heavy gage): Ground wire
Four-Wire Harness (Trailer Brake Controller)
•Black: Ground
•Red/White Stripe: Fused Battery
•Dark Blue: Trailer Brake Feed
•Light Blue: Fused Stoplamp/CHMSL
286

Service........................................................ 290
Accessories and Modifications................... 290
California Proposition 65 Warning.............. 291
Doing Your Own Service Work.................. 291
Adding Equipment to the Outside of
Your Vehicle.......................................... 292
Fuel............................................................. 292
Gasoline Octane........................................ 293
Gasoline Specifications.............................. 293
California Fuel........................................... 293
Additives................................................... 294
Fuel E85 (85% Ethanol)............................ 295
Fuels in Foreign Countries........................ 296
Filling the Tank......................................... 297
Filling a Portable Fuel Container............... 299
Checking Things Under the Hood.............. 300
Hood Release........................................... 300
Engine Compartment Overview.................. 302
Engine Oil (Gasoline Engine).................... 303
Engine Oil Life System
(Gasoline Engine).................................. 306
Engine Air Cleaner/Filter............................ 308
Automatic Transmission Fluid.................... 309
Engine Coolant.......................................... 312Radiator Pressure Cap.............................. 315
Engine Overheating................................... 315
Cooling System......................................... 317
Engine Fan Noise..................................... 323
Power Steering Fluid................................. 323
Windshield Washer Fluid........................... 324
Brakes...................................................... 325
Battery...................................................... 329
Jump Starting............................................ 330
All-Wheel Drive........................................... 336
Rear Axle.................................................... 337
Front Axle................................................... 338
Noise Control System................................. 338
Tampering with Noise Control System
Prohibited.............................................. 338
Bulb Replacement....................................... 340
Halogen Bulbs........................................... 340
Headlamps................................................ 340
Front Turn Signal, Sidemarker and
Parking Lamps....................................... 342
Center High-Mounted Stoplamp (CHMSL) ... 342
Taillamps................................................... 343
Replacement Bulbs................................... 344
Section 5 Service and Appearance Care
287

Electrical System........................................ 393
Add-On Electrical Equipment..................... 393
Headlamp Wiring....................................... 393
Windshield Wiper Fuses............................ 393Fuses and Circuit Breakers....................... 393
Floor Console Fuse Block......................... 394
Engine Compartment Fuse Block............... 395
Capacities and Specications.................... 398
Section 5 Service and Appearance Care
289

California Proposition 65 Warning
Most motor vehicles, including this one, contain
and/or emit chemicals known to the State of
California to cause cancer and birth defects or
other reproductive harm. Engine exhaust, many
parts and systems (including some inside the
vehicle), many fluids, and some component wear
by-products contain and/or emit these chemicals.
Doing Your Own Service Work
{CAUTION:
You can be injured and your vehicle could
be damaged if you try to do service work
on a vehicle without knowing enough
about it.
Be sure you have sufficient knowledge,
experience, the proper replacement
parts, and tools before you attempt
any vehicle maintenance task.
CAUTION: (Continued)
CAUTION: (Continued)

Be sure to use the proper nuts, bolts,
and other fasteners. English and
metric fasteners can be easily
confused. If you use the wrong
fasteners, parts can later break or
fall off. You could be hurt.
If you want to do some of your own service
work, you should use the proper service manual.
It tells you much more about how to service
your vehicle than this manual can. To order the
proper service manual, seeService Publications
Ordering Information on page 440.
Your vehicle has an airbag system. Before
attempting to do your own service work, see
Servicing Your Airbag-Equipped Vehicle on
page 96.
You should keep a record with all parts receipts
and list the mileage and the date of any service
work you perform. SeeMaintenance Record
on page 419.
291