
Timer
Press the trip/fuel button until TIMER displays. This
display can be used as a timer.
To start the timer, press the set/reset button while TIMER
is displayed. The display will show the amount of time
that has passed since the timer was last reset, not
including time the ignition is off. Time will continue to be
counted as long as the ignition is on, even if another
display is being shown on the DIC. The timer will record
up to 99 hours, 59 minutes and 59 seconds (99:59:59)
after which the display will return to zero.
To stop the timer, press the set/reset button briefly while
TIMER is displayed.
To reset the timer to zero, press and hold the set/reset
button while TIMER is displayed.
Average Speed
Press the trip/fuel button until AVERAGE SPEED
displays. This display shows the average speed of the
vehicle in miles per hour (mph) or kilometers per
hour (km/h). This average is calculated based on the
various vehicle speeds recorded since the last reset of
this value. To reset the value, press and hold the
set/reset button. The display will return to zero.
Digital Tachometer
Press the trip/fuel button until Tachometer ##00 RPM
displays. This display shows the engine speed in
revolutions per minute (RPM).
Blank Display
This display shows no information.
Vehicle Information Menu Items
T
(Vehicle Information):Press this button to scroll
through the following menu items:
Oil Life
Press the vehicle information button until OIL LIFE
REMAINING displays. This display shows an estimate of
the oil’s remaining useful life. If you see 99% OIL LIFE
REMAINING on the display, that means 99% of the
current oil life remains. The engine oil life system will alert
you to change the oil on a schedule consistent with your
driving conditions.
When the remaining oil life is low, the CHANGE ENGINE
OIL SOON message will appear on the display. See
“CHANGE ENGINE OIL SOON” underDIC Warnings and
Messages on page 3-50. You should change the oil as
soon as possible. SeeEngine Oil on page 5-15.In
addition to the engine oil life system monitoring the oil life,
additional maintenance is recommended in the
Maintenance Schedule in this manual. SeeScheduled
Maintenance on page 6-4for more information.
3-46

Hydroplaning
Hydroplaning is dangerous. Water can build up under
your vehicle’s tires so they actually ride on the water.
This can happen if the road is wet enough and you are
going fast enough. When your vehicle is hydroplaning, it
has little or no contact with the road.
There is no hard and fast rule about hydroplaning.
The best advice is to slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet weather driving tips
include:
•Allow extra following distance.
•Pass with caution.
•Keep windshield wiping equipment in good shape.
•Keep the windshield washer fluid reservoir filled.
•Have good tires with proper tread depth. SeeTires
on page 5-54.
•Turn off cruise control.
Before Leaving on a Long Trip
To prepare your vehicle for a long trip, consider having
it serviced by your dealer/retailer before departing.
Things to check on your own include:
•Windshield Washer Fluid:Reservoir full? Windows
clean — inside and outside?
•Wiper Blades:In good shape?
•Fuel, Engine Oil, Other Fluids:All levels checked?
•Lamps:Do they all work and are lenses clean?
•Tires:Are treads good? Are tires inflated to
recommended pressure?
•Weather and Maps:Safe to travel? Have
up-to-date maps?
4-13

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.
E85 has less energy per gallon than gasoline, so you
will need to refill the fuel tank more often when using E85
than when you are using gasoline. SeeFilling the Tank
on page 5-10.
Notice:Some additives are not compatible with
E85 fuel and can harm the vehicle’s fuel system.
Do not add anything to E85. Damage caused
by additives would not be covered by the vehicle
warranty.Notice:This 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 the
vehicle warranty.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel might be hard
to find. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel would not
be covered by the vehicle warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in
the country where you will be driving.
5-9

When to Add Engine Oil
If the oil is below the cross-hatched area at the tip
of the dipstick, add at least one quart/liter of the
recommended oil. This section explains what kind
of oil to use. For engine oil crankcase capacity,
seeCapacities and Specifications on page 5-110.
Notice:Do not add too much oil. If the engine
has so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, the engine could be damaged.SeeEngine Compartment
Overview on page 5-14
for the location of the
engine oil fill cap.
Add enough oil to put the level somewhere in the proper
operating range. Push the dipstick all the way back in
when you are through.
5-16

What Kind of Engine Oil to Use
Look for three things:
•GM6094M
Use only an oil that meets GM Standard GM6094M.
•SAE 5W-30
SAE 5W-30 is best for the vehicle. These numbers
on an oil container show its viscosity, or thickness.
Do not use other viscosity oils such as SAE 20W-50.
•American Petroleum Institute (API) starburst symbol
Oils meeting these
requirements should have
the starburst symbol on
the container. This symbol
indicates that the oil has
been certified by the
American Petroleum
Institute (API).
Notice:Use only engine oil identi ed as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certi ed For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
the vehicle warranty.
Cold Temperature Operation
If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), use either an
SAE 5W-30 synthetic oil or an SAE 0W-30 engine oil.
Both provide easier cold starting for the engine at
extremely low temperatures. Always use an oil that
meets the required specification, GM6094M. See
“What Kind of Engine Oil to Use” for more information.
5-17

Engine Oil Additives / Engine Oil
Flushes
Do not add anything to the oil. The recommended
oils with the starburst symbol that meet GM Standard
GM6094M are all you need for good performance and
engine protection.
Engine oil system flushes are not recommended and
could cause engine damage not covered by the vehicle
warranty.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that lets you know
when to change the engine oil and filter. This is based
on engine revolutions and engine temperature, and not
on mileage. Based on driving conditions, the mileage
at which an oil change will be indicated can vary
considerably. For the oil life system to work properly,
you must reset the system every time the oil is changed.When the system has calculated that oil life has been
diminished, it will indicate that an oil change is necessary.
A CHANGE ENGINE OIL SOON message will come on.
SeeDIC Warnings and Messages on page 3-50. Change
the oil as soon as possible within the next 600 miles
(1 000 km). It is possible that, if you are driving under the
best conditions, the oil life system might not indicate that
an oil change is necessary for over a year. However, the
engine oil and filter must be changed at least once a year
and at this time the system must be reset. Your dealer/
retailer has trained service people who will perform this
work using genuine parts and reset the system. It is also
important to check the oil regularly and keep it at the
proper level.
If the system is ever reset accidentally, you must
change the oil at 3,000 miles (5 000 km) since the
last oil change. Remember to reset the oil life system
whenever the oil is changed.
5-18

To inspect or replace the engine air cleaner/filter, do the
following:
1. Unhook the retainer clips and remove the cover.
2. Lift the filter out of the engine air cleaner/filter
housing. Care should be taken to dislodge as
little dirt as possible.
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/filter
off can cause you or others to be burned. The air
cleaner not only cleans the air; it helps to stop
flames if the engine backfires. If it is not there and
the engine backfires, you could be burned. Do not
drive with it off, and be careful working on the
engine with the air cleaner/filter off.Notice:If the air cleaner/ lter is off, a back re
can cause a damaging engine re. And, dirt
can easily get into the 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 on page 6-6, and be sure
to use the transmission fluid listed inRecommended
Fluids and Lubricants on page 6-13.
5-21

What to Use
{CAUTION:
Adding only plain water to the cooling system can
be dangerous. Plain water, or some other liquid
such as alcohol, can boil before the proper coolant
mixture will. The vehicle’s coolant warning system
is set for the proper coolant mixture. With plain
water or the wrong mixture, the engine could get
too hot but you would not get the overheat
warning. The engine could catch fire and you or
others could be burned. Use a 50/50 mixture of
clean, drinkable water and DEX-COOL
®coolant.Use a 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant. If using this mixture, nothing else
needs to be added. This mixture:
•Gives freezing protection down to−34°F (−37°C),
outside temperature.
•Gives boiling protection up to 265°F (129°C),
engine temperature.
•Protects against rust and corrosion.
•Will not damage aluminum parts.
•Helps keep the proper engine temperature.
Notice:If an improper coolant mixture is used,
the engine could overheat and be badly damaged.
The repair cost would not be covered by the vehicle
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core, and
other parts.
Notice:If extra inhibitors and/or additives are used
in the vehicle’s cooling system, the vehicle could
be damaged. Use only the proper mixture of
the engine coolant listed in this manual for the
cooling system. SeeRecommended Fluids and
Lubricants on page 6-13for more information.
5-26