2007 CHEVROLET EXPRESS PASSANGER transmission

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.
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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
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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

A. Battery. SeeBattery on page 329.
B. Radiator Pressure Cap. SeeRadiator Pressure
Cap on page 315.
C. Coolant Recovery Tank. SeeCooling System
on page 317.
D. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 309.
E. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil (Gasoline Engine) on
page 303.
F. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil (Gasoline Engine) on
page 303.
G. Engine Air Cleaner/Filter. SeeEngine
Air Cleaner/Filter on page 308.
H. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 323.
I. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 325.
J. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 324.Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see “Engine
Oil” in the DURAMAX®Diesel Engine Supplement.
Checking Engine Oil
It is a good idea to check the engine oil every time
you get fuel. In order to get an accurate reading,
the oil must be warm and the vehicle must be
on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 302
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several
minutes to drain back into the oil pan. If you
do not do this, the oil dipstick might not
show the actual level.
2. Pull out the dipstick and clean it with a paper
towel or cloth, then push it back in all the
way. Remove it again, keeping the tip down,
and check the level.
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3. Clean the engine air cleaner/filter housing.
4. Inspect or replace the engine air cleaner/filter.
Make sure that the filter fits properly into the
housing.
5. Reinstall the cover and fasten the
retaining clips.
{CAUTION:
Operating the engine with the air cleaner/
lter off can cause you or others to be
burned. The air cleaner not only cleans the
air; it helps to stop ames if the engine
backres. If it is not there and the engine
backres, you could be burned. Do not
drive with it off, and be careful working on
the engine with the air cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre
can cause a damaging engine re. And, dirt
can easily get into your engine, which will
damage it. Always have the air cleaner/lter
in place when you are driving.
Automatic Transmission Fluid
If your vehicle has the DURAMAX®Diesel engine,
see the DURAMAX®Diesel manual for more
information.
When to Check and Change
Automatic Transmission Fluid
A good time to check your automatic transmission
fluid level is when the engine oil is changed.
Change the fluid and filter at the intervals listed in
Additional Required Services (Gasoline Engine)
on page 408, and be sure to use the transmission
fluid listed inRecommended Fluids and
Lubricants on page 415.
309

How to Check Automatic
Transmission Fluid
Because this operation can be a little difficult, you
may choose to have this done at the dealer/retailer
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading
on the dipstick.
Notice:Too much or too little uid can
damage your transmission. Too much can
mean that some of the uid could come out
and fall on hot engine parts or exhaust system
parts, starting a re. Too little uid could
cause the transmission to overheat. Be sure
to get an accurate reading if you check
your transmission uid.
Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:
•When outside temperatures are
above 90°F (32°C).
•At high speed for quite a while.
•In heavy traffic — especially in hot weather.
•While pulling a trailer.To get the right reading, the fluid should be
at normal operating temperature, which is
180°F to 200°F (82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are
above 50°F (10°C). If it is colder than 50°F (10°C),
drive the vehicle in DRIVE (D) until the engine
temperature gage moves and then remains
steady for 10 minutes.
A cold fluid check can be made after the vehicle
has been sitting for eight hours or more with
the engine off, but this is used only as a reference.
Let the engine run at idle for five minutes if
outside temperatures are 50°F (10°C) or more.
If it is colder than 50°F (10°C), you may have
to idle the engine longer. Should the fluid level be
low during this cold check, you must check the
fluid hot before adding fluid. Checking the fluid
hot will give you a more accurate reading of
the fluid level.
310

Checking the Fluid Level
Prepare your vehicle as follows:
1. Park your vehicle on a level place. Keep the
engine running.
2. With the parking brake applied, place the shift
lever in PARK (P).
3. With your foot on the brake pedal, move the
shift lever through each gear range, pausing
for about three seconds in each range.
Then, position the shift lever in PARK (P).
4. Let the engine run at idle for three minutes
or more.
Then, without shutting off the engine, follow
these steps:
The transmission
dipstick is located near
the center of the
engine compartment
and will be labeled with
the graphic shown.SeeEngine Compartment Overview on page 302
for more information on location.
1. Flip the handle up and then pull out the
dipstick and wipe it with a clean rag or
paper towel.
2. Push it back in all the way, wait three seconds
and then pull it back out again.
3. Check both sides of the dipstick, and read the
lower level. The fluid level must be in the
COLD area for a cold check or in the HOT
or cross-hatched area for a hot check. Be sure
to keep the dipstick pointed down to get an
accurate reading.
4. If the fluid level is in the acceptable range,
push the dipstick back in all the way; then
flip the handle down to lock the dipstick
in place.
311

How to Add Automatic
Transmission Fluid
Refer to the Maintenance Schedule to determine
what kind of transmission fluid to use. See
Recommended Fluids and Lubricants on page 415.
Using a funnel, add fluid down the transmission
dipstick tube only after checking the transmission
fluid while it is hot. A cold check is used only
as a reference. If the fluid level is low, add only
enough of the proper fluid to bring the level up to
the HOT area for a hot check. It does not take
much fluid, generally less than one pint (0.5 L).
Do not overfill.
Notice:Use of the incorrect automatic
transmission uid may damage your vehicle,
and the damages may not be covered by
your warranty. Always use the automatic
transmission uid listed inRecommended
Fluids and Lubricants on page 415.
•After adding fluid, recheck the fluid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
•When the correct fluid level is obtained, push
the dipstick back in all the way; then flip the
handle down to lock the dipstick in place.
Engine Coolant
If your vehicle has the DURAMAX®Diesel engine,
see the DURAMAX®Diesel manual for more
information.
The cooling system in your vehicle is filled with
DEX-COOL
®engine coolant. This coolant is
designed to remain in your vehicle for five years
or 150,000 miles (240 000 km), whichever
occurs first, if you add only DEX-COOL
®
extended life coolant.
The following explains your cooling system and
how to add coolant when it is low. If you have
a problem with engine overheating, seeEngine
Overheating on page 315.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
•Give freezing protection down to−34°F (−37°C).
•Give boiling protection up to 265°F (129°C).
•Protect against rust and corrosion.
•Help keep the proper engine temperature.
•Let the warning lights and gages work as
they should.
312