engine CHEVROLET EXPRESS PASSANGER 2007 1.G Workshop Manual

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

Adding Equipment to the Outside
of Your Vehicle
Things you might add to the outside of your
vehicle can affect the airflow around it. This may
cause wind noise and affect windshield washer
performance. Check with your dealer before
adding equipment to the outside of your vehicle.
Fuel
If your vehicle has a diesel engine, see
“Diesel Fuel Requirements and Fuel System”
in the DURAMAX
®Diesel Supplement.
For vehicles with gasoline engines, please
read this.
Gasoline
Use of the recommended fuel is an important
part of the proper maintenance of your vehicle.
To help keep the engine clean and maintain
optimum vehicle performance, GM recommends
the use of gasoline advertised as TOP TIER
Detergent Gasoline.
The 8th digit of the Vehicle Identification
Number (VIN) shows the code letter or number
that identifies your vehicle’s engine. The VIN
is at the top left of the instrument panel.
SeeVehicle Identication Number (VIN)
on page 392.
If your vehicle has the 5.3L V8 engine
(VIN Code Z), you can use either regular
unleaded gasoline or ethanol fuel containing
up to 85% ethanol (E85); also seeFuel E85
(85% Ethanol) on page 295. In all other gasoline
engines, use only regular unleaded gasoline.
292

Gasoline Octane
Use regular unleaded gasoline with a posted
octane rating of 87 or higher. If the octane rating
is less than 87, you might notice an audible
knocking noise when you drive, commonly referred
to as spark knock. If this occurs, use a gasoline
rated at 87 octane or higher as soon as possible.
If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, the engine
needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM
specification D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines may
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl
(MMT). General Motors recommends against the
use of gasolines containing MMT. SeeAdditives
on page 294for additional information.
California Fuel
If your vehicle is certified to meet California
Emissions Standards, it is designed to operate
on fuels that meet California specifications.
See the underhood emission control label.
If this fuel is not available in states adopting
California emissions standards, your vehicle will
operate satisfactorily on fuels meeting federal
specifications, but emission control system
performance may be affected. The malfunction
indicator lamp may turn on and your vehicle may
fail a smog-check test. SeeMalfunction Indicator
Lamp on page 178. If this occurs, return to
your authorized GM dealer for diagnosis. If it is
determined that the condition is caused by the
type of fuel used, repairs may not be covered
by your warranty.
293

Additives
To provide cleaner air, all gasolines in the
United States are now required to contain additives
that will help prevent engine and fuel system
deposits from forming, allowing your emission
control system to work properly. In most cases,
you should not have to add anything to your
fuel. However, some gasolines contain only the
minimum amount of additive required to meet
U.S. Environmental Protection Agency regulations.
To help keep fuel injectors and intake valves
clean, or if your vehicle experiences problems due
to dirty injectors or valves, look for gasoline that
is advertised as TOP TIER Detergent Gasoline.
Also, your dealer has additives that will help
correct and prevent most deposit-related problems.
Gasolines containing oxygenates, such as
ethers and ethanol, and reformulated gasolines
may be available in your area. General Motors
recommends 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:Your 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 your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT); ask the attendant where you
buy gasoline whether the fuel contains MMT.
General Motors recommends against the use of
such gasolines. Fuels containing MMT can reduce
the life of spark plugs and the performance of
the emission control system may be affected.
The malfunction indicator lamp may turn on.
If this occurs, return to your dealer for service.
294

Fuel E85 (85% Ethanol)
The 8th digit of the Vehicle Identification
Number (VIN) shows the code letter or number
that identifies your vehicle’s engine. The VIN is
at the top left of the instrument panel. See
Vehicle Identication Number (VIN) on page 392.
If your vehicle has the 5.3L V8 engine (VIN Code Z
only), you can use either regular unleaded gasoline
or ethanol fuel containing up to 85% ethanol (E85);
also seeFuel on page 292. In all other engines,
use only the unleaded gasoline described under
Gasoline Octane on page 293.
Only vehicles that have the 5.3L V8 engine
(VIN Code Z) can use 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%.At a minimum, E85 should meet ASTM
Specification D 5798. By definition, this means
that fuel labeled E85 will have an ethanol content
between 70% and 85%. Filling the fuel tank
with fuel mixtures that do not meet ASTM
specifications can affect driveability and could
cause the check engine light to come on.
To ensure quick starts in the wintertime, the
E85 fuel must be formulated properly for your
climate according to ASTM specification D 5798.
If you have trouble starting on E85, it could
be because the E85 fuel is not properly formulated
for your climate. If this happens, switching to
gasoline or adding gasoline to the fuel tank can
improve starting. For good starting and heater
efficiency below 32°F (0°C), the fuel mix in the fuel
tank should contain no more than 70% ethanol.
It is best not to alternate repeatedly between
gasoline and E85. If you do switch fuels, it
is recommended that you add as much fuel as
possible — do not add less than three gallons
(11 L) when refueling. You should drive the
vehicle immediately after refueling for at least
seven miles (11 km) to allow the vehicle to adapt
to the change in ethanol concentration.
295