2007 CHEVROLET EXPRESS PASSANGER check engine

Hill and Mountain Roads
Driving on steep hills or mountains is different
from driving in flat or rolling terrain.If you drive regularly in steep country, or if you are
planning to visit there, here are some tips that
can make your trips safer and more enjoyable.
•Keep your vehicle in good shape. Check
all fluid levels and also the brakes, tires,
cooling system, and transmission. These parts
can work hard on mountain roads.
{CAUTION:
If you do not shift down, the brakes could
get so hot that they would not work well.
You would then have poor braking or
even none going down a hill. You could
crash. Shift down to let the engine assist
the brakes on a steep downhill slope.
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{CAUTION:
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 pipe and/or the fuel operated
heater exhaust system, if equipped. And
check around again from time to time to
be sure snow does not collect there. If
your vehicle has a diesel engine and a
fuel operated heater, see “Fuel Operated
Heater (FOH)” in the diesel engine
supplement.
Open a window just a little on the side of
the vehicle that is away from the wind.
This will help keep CO out.Run your engine only as long as you must. This
saves fuel. When you run the engine, make it go a
little faster than just idle. That is, push the
accelerator slightly. This uses less fuel for the heat
that you get and it keeps the battery (or batteries)
charged. You will need a well-charged battery (or
batteries) to restart the vehicle, and possibly for
signaling later on with your headlamps. Let the
heater run for a while.
Then, shut the engine off and close the window
almost all the way to preserve the heat. Start
the engine again and repeat this only when you
feel really uncomfortable from the cold. But do it as
little as possible. Preserve the fuel as long as
you can. To help keep warm, you can get out of
the vehicle and do some fairly vigorous exercises
every half hour or so until help comes.
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Towing a Trailer
If your vehicle has a diesel engine, see the
DURAMAX®Diesel manual for more information.
{CAUTION:
If you do not use the correct equipment
and drive properly, you can lose control
when you pull a trailer. For example, if the
trailer is too heavy, the brakes may not
work well — or even at all. You and your
passengers could be seriously injured.
You may also damage your vehicle; the
resulting repairs would not be covered by
your warranty. Pull a trailer only if you
have followed all the steps in this section.
Ask your dealer/retailer for advice and
information about towing a trailer with
your vehicle.Notice:Pulling a trailer improperly can
damage your vehicle and result in costly repairs
that would not be covered by your warranty.
Always follow the instructions in this section
and check with your dealer/retailer for more
information about towing a trailer with your
vehicle.
To identify the trailering capacity of your vehicle,
you should read the information in “Weight of
the Trailer” that appears later in this section.
Trailering is different than just driving your vehicle
by itself. Trailering means changes in acceleration,
braking, handling, durability and fuel economy.
Successful, safe trailering takes correct equipment,
and it has to be used properly.
That’s the reason for this part. In it are many
time-tested, important trailering tips and safety
rules. Many of these are important for your safety
and that of your passengers. So please read
this section carefully before you pull a trailer.
269

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

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

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