
Malfunction Indicator Lamp
Service Engine Soon Light
If this light comes on or
flashes while you are
driving, two things may
happen.
First, you will not notice any difference in engine
performance, but your tail pipe emissions may increase.
Second, your engine may not run properly or may
stall without warning. If either of these things happen,
drive or tow your vehicle to your dealer for service.
This light should come on when the ignition is on, but
the engine is not running, as a check to show you
it is working. If it does not come on at all, have
it repaired.
Notice:If you keep driving your vehicle with this
light on, after awhile, your emission controls
may not work as well, your fuel economy may not
be as good, and your engine may not run as
smoothly. This could lead to costly repairs that may
not be covered by your warranty.
Oil Pressure Gage
The engine oil pressure gage, on the lower right portion
of your instrument panel cluster, shows engine oil
pressure in psi (pounds per square inch) or in kPa
(kilopascals). Oil pressure may vary with outside
temperature and oil viscosity, but readings of
30 to 40 psi (205 to 275 kPa) on gasoline engines at
operating temperature and moderate road speeds
are normal. If you have a diesel engine, the normal
operating range should be between 35 and 70 psi
(240 to 480 kPa).
United StatesCanada
3-38

A reading in the low pressure zone may be caused by a
dangerously low oil level or other problem.
If you have a Caterpillar
®diesel engine, also see your
Caterpillar®Operation & Maintenance Manual.
{CAUTION:
Do not keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.
Low Oil Level Light
This light should come on
as a check, when you start
your engine. If the light
fails to come on, have it
repaired as soon as
possible so you will be
aware when the oil level
is low.
Vehicles equipped with Caterpillar
®diesel engines may
not have a low oil level light. In this case, the light
will neither come on as a check when you start your
engine, nor will it come on to indicate a low oil level.
If this light comes on and stays on, it means your engine
is low on oil. You need to check the oil level right
away. SeeEngine Oil (Caterpillar
®Diesel Engine) on
page 5-24orEngine Oil (DURAMAX®Diesel) on
page 5-24orEngine Oil (Gasoline Engine) on page 5-28
for further information.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.
3-39

Change Engine Oil Light
The change engine oil light
should come on briefly as
a bulb check when you
start the engine. If the light
does not come on, have
it serviced.
If the change engine oil light comes on and stays on
after you start the engine, have the oil changed.
For additional information on when to change engine oil
for gasoline engines or DURAMAX
®diesel engines,
seeEngine Oil (Caterpillar®Diesel Engine) on page 5-24
orEngine Oil (DURAMAX®Diesel) on page 5-24or
Engine Oil (Gasoline Engine) on page 5-28and
Scheduled Maintenance on page 6-5. To reset the
change engine oil light, seeEngine Oil Life System
(Gasoline Engine) on page 5-31orEngine Oil Life
System (DURAMAX
®Diesel) on page 5-33orEngine
Oil Life System (Caterpillar®Diesel Engine) on
page 5-34.
Engine Overspeed Warning Light
If your vehicle has this
light, it will come on if your
engine is operating at
too many revolutions
per minute (rpm).
It will also come on for a moment as a check when you
start your engine.
If it comes on when you’re driving, reduce your engine
speed immediately.
Engine Shutdown Warning Light
If your vehicle has the
engine shutdown feature,
this light will come on
when engine shutdown is
active.
For more information, seeEngine Alarm and Automatic
ShutdownunderStarting the Diesel Engine on
page 2-15.
3-40

Transmission Temperature Gage
If you have an automatic
transmission and this
gage, it is located above
the switchbank in the
center of the instrument
panel.
When your ignition is on, the gage shows the
temperature of the transmission oil. A reading in the
warning zone, the red area beginning at 300°F (150°C),
means you must stop driving and check into the
cause. One possible cause is a low oil level in the
transmission.
Notice:If you drive your vehicle with the
transmission temperature gage above normal
operating range, you can damage the transmission.
This could lead to costly repairs that would not
be covered by your warranty. Do not drive your
vehicle while the transmission temperature gage
reading is above normal. See your dealer for service.
Exhaust Brake Indicator Light
If your vehicle is equipped
with an exhaust brake, you
will have this light,
located above the climate
controls in the center
of the instrument panel.
The exhaust brake indicator light will come on and stay
on whenever the diesel engine exhaust brake or
exhaust restrictor is active. For more information, see
Diesel Engine Exhaust Brake on page 2-27andExhaust
Restrictor (Engine Warm-Up) on page 2-22.
3-41

Low Washer Fluid Warning Light
This light will come on
when your vehicle is low
on windshield washer fluid.
For more information, seeWindshield Washer Fluid on
page 5-48.
Check Gages Warning Light
This light will come on as
you’re starting the engine,
just as a check.
If this light comes on and stays on while you are driving.
It means that either your engine coolant temperature
gage or your engine oil pressure gage may be showing
a reading in the warning zone.
When the check gages light comes on, you will also
hear a warning tone. The tone and the light will
stay activated until the problem is corrected.
This light may also come on if your vehicle is equipped
with the optional automatic engine shutdown system
and engine shutdown has begun. SeeEngine Alarm and
Automatic ShutdownunderStarting the Diesel Engine
on page 2-15.
3-44

Service............................................................5-3
California Proposition 65 Warning.....................5-3
Doing Your Own Service Work.........................5-4
Engine Fan Breakage.....................................5-5
Fuel................................................................5-6
Gasoline Octane............................................5-6
Gasoline Specifications....................................5-6
Additives.......................................................5-6
Diesel Engine Fuel.........................................5-7
What Fuel to Use...........................................5-8
Very Cold Weather Operation.........................5-10
Water in Fuel...............................................5-10
Running Out of Fuel.....................................5-17
Fuel Filter Replacement.................................5-18
Fuels in Foreign Countries.............................5-19
Filling the Tank............................................5-20
Filling a Portable Fuel Container.....................5-21
Checking Things Under the Hood....................5-22
Hood Latches...............................................5-22
Engine Oil (Caterpillar
®Diesel Engine).............5-24
Engine Oil (DURAMAX®Diesel)......................5-24
Engine Oil (Gasoline Engine)..........................5-28
Engine Oil Life System (Gasoline Engine)........5-31
Engine Oil Life System (DURAMAX
®Diesel).....5-33
Engine Oil Life System
(Caterpillar
®Diesel Engine).........................5-34Engine Air Cleaner/Filter................................5-35
Automatic Transmission Fluid.........................5-36
Manual Transmission Fluid.............................5-37
Engine Coolant
(Gas and DURAMAX
®Engines)...................5-38
Engine Coolant (Caterpillar®Diesel Engines).....5-40
Coolant Surge Tank Pressure Cap..................5-40
Engine Overheating.......................................5-40
Cooling System
(Gas and DURAMAX
®Engines)...................5-42
Engine Fan Noise.........................................5-47
Power Steering Fluid.....................................5-47
Windshield Washer Fluid................................5-48
Brakes........................................................5-49
Battery........................................................5-58
Jump Starting...............................................5-59
Rear Axle.......................................................5-64
Rear Axle Shift Motor....................................5-65
Four-Wheel Drive............................................5-65
Front Axle......................................................5-66
Noise Control System.....................................5-67
Tampering with Noise Control System
Prohibited.................................................5-67
Bulb Replacement..........................................5-68
Windshield Wiper Blade Replacement..............5-69
Section 5 Service and Appearance Care
5-1

Notice:Your vehicle was not designed for fuel that
contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the 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 authorized GM dealer for
service.Diesel Engine Fuel
For the Caterpillar®diesel, see the Caterpillar®
Operation & Maintenance Manual for information
concerning fuel usage.
Notice:Diesel fuel or fuel additives not
recommended in this manual could damage your
fuel system and engine. Your warranty would
not cover this damage. And:
Diesel fuel that has been mixed with engine oil
or automatic transmission uid could damage
your engine and emission controls.
Aftermarket diesel fuel additives are not tested
by General Motors. Some additives, particularly
those which contain alcohol or water
emulsi ers, may damage your fuel system. If
you believe that unique circumstances call for a
fuel additive to be used, consult your dealer
for advice.
If you ever run out of diesel fuel, it can be
difficult to restart your engine. To avoid
this, never let your tank get empty.
If gasoline is ever accidentally added to the fuel
tank, to avoid severe engine damage, do not run the
engine until the fuel tank can be drained.
If you run out of fuel,Running Out of Fuel on page 5-17
tells you how to restart your engine.
5-7

What Fuel to Use
In the United States, for best results use No. 2-D diesel
fuel year-round (above and below freezing conditions)
as oil companies blend No. 2-D fuel to address climate
differences. No. 1-D diesel fuel may be used in very
cold temperatures (when it stays below 0°F or−18°C);
however, it will produce a power and fuel economy
loss. Avoid the use of No. 1-D diesel fuel in warm or hot
climates. It may result in stalling, poor starting when
the engine is hot, and may damage the fuel injection
system.
At a minimum, the diesel fuel you use should meet the
latest version of ASTM specification D 975 (Grade
Low Sulfur) in the United States. In addition, the Engine
Manufacturers Association (EMA) has identified
properties of an improved diesel fuel for better engine
performance and durability. Diesel fuels corresponding
to the EMA Recommended Guideline on Premium
Diesel Fuel (FQP-1A) could provide better starting, less
noise, and better vehicle performance. If there are
questions about the fuel you are using, contact your fuel
supplier.
If your vehicle has the 6.6L engine, it is acceptable to
use diesel fuel containing up to 5% biodiesel (B5),
but the final blended fuel must meet the same
specification, ASTM D 975 (Grade Low Sulfur), as other
fuels used in your vehicle, and the biodiesel used for
making this fuel must meet the latest version ofASTM specification D 6751. Biodiesel is produced from
vegetable oils or animal fat that have been chemically
modified to reduce the possibility of damage to your fuel
system and engine. Higher concentration (i.e., greater
than B5) biodiesel-containing fuels or the use of
unmodified bio-oils blended into diesel fuel at any
concentration is not recommended and could damage
your fuel system and engine. Such damage would
not be covered by your warranty. If there are questions
about the biodiesel-containing fuels you are using,
contact your fuel supplier.
Diesel fuel may foam when you fill your tank. This can
cause the automatic pump nozzle to shut off, even
though your tank is not full. If this happens, just
wait for the foaming to stop and then continue to fill
your tank.
{CAUTION:
Heat coming from the engine may cause the
fuel to expand and force the fuel out of your
tank. If something ignites the fuel, a re could
start and people could be burned. To help
avoid this, ll your fuel tank only until the
automatic nozzle shuts off. Do not try to top
it off.
5-8