2003 GMC SIERRA DIC

As in the chart shown previously, SAE 5W-30 is the
only viscosity grade recommended for your vehicle.
You should look for and use only oils which have the
API Starburst symbol and which are also identified
as SAE 5W-30. If you cannotfind such SAE 5W-30 oils,
you can use an SAE 10W-30 oil which has the API
Starburst symbol, if it’s going to be 0°F(−18°C)
or above. Do not use other viscosity grade oils, such as
SAE 10W-40 or SAE 20W-50 under any conditions.
Notice:Use only engine oil with the American
Petroleum Institute Certified For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
GM Goodwrench
®oil meets all the requirements for
your vehicle.
If you are in an area of extreme cold, where the
temperature falls below−20°F(−29°C),itis
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Don’t add anything to your oil. The recommended oils
with the starburst symbol are all you will need for
good performance and engine protection.
When to Change Engine Oil (GM Oil
Life System)
Your vehicle has a computer system that lets you know
when to change the engine oil andfilter. 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. Change your oil as soon as possible within
the next two times you stop for fuel. It is possible that,
if you are driving under the best conditions, the oil
life system may not indicate that an oil change is
necessary for over a year. However, your engine oil and
filter must be changed at least once a year and at
this time the system must be reset. Your dealer has
GM-trained service people who will perform this
work using genuine GM parts and reset the system. It is
also important to check your oil regularly and keep it
at the proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed.
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How to Reset the CHANGE ENGINE OIL
Message
The GM Oil Life System calculates when to change
your engine oil andfilter based on vehicle use. Anytime
your oil is changed, reset the system so it can
calculate when the next oil change is required. If a
situation occurs where you can change your oil prior to
a CHANGE ENGINE OIL message being turned on,
reset the system.
To reset the CHANGE ENGINE OIL message, see“GM
Oil Life System”underDIC Operation and Displays
on page 3-42for vehicles equipped with the DIC, or do
the following:
1. Turn the ignition key to RUN with the engine off.
2. Fully press and release the accelerator pedal three
times withinfive seconds.
If the OIL LIFE RESET messageflashes for 10 seconds,
the system is reset. If the system will not reset, try the
procedure again. If the system still does not reset,
see your dealer for service.
What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Don’t let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good
hand cleaner. Wash or properly dispose of clothing or
rags containing used engine oil. See the manufacturer’s
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from the
filter before disposal. Never dispose of oil by putting it
in the trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Instead, recycle it by
taking it to a place that collects used oil. If you have a
problem properly disposing of your used oil, ask
your dealer, a service station or a local recycling center
for help.
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Engine Air Cleaner/Filter
SeeEngine Compartment
Overview on page 5-12for
location of engine air
cleaner/filter and change
indicator (if equipped).
When to Inspect
If your vehicle is equipped with afilter change indicator
it lets you know when thefilter needs to be replaced.
Inspect the air cleaner/filter change indicator every
15,000 miles (25 000 km) and replace thefilter if
necessary. Vehicles without a change indicator inspect
the air cleaner/filter every 15,000 miles (25 000 km)
and replace thefilter every 30,000 miles (50 000 km).
If you are driving in dusty/dirty conditions, inspect
thefilter or change indicator at each engine oil change.
How to Inspect
Locate thefilter change indicator. When the change
indicator turns black or is in the red/orange“change”
zone, replace thefilter and reset the indicator.
To inspect the air cleaner/filter, remove thefilter from
the vehicle and lightly shakefilter to release loose dust
and dirt. If thefilter remains“caked”with dirt, a new
filter is required.
To inspect and replace thefilter and reset the indicator
(if equipped), do the following:
The air cleaner/filter assembly is located on the front
corner of the engine compartment on the passenger’s
side of the vehicle.
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{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap—even a little—when the engine and
radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the FULL
COLD mark.
If the LOW COOLANT LEVEL message comes on and
stays on, it means you’re low on engine coolant.
See“Low Coolant Level”underDIC Warnings and
Messages on page 3-51.
Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixtureat the surge tank, but only when the
engine is cool.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Don’t spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight.
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Coolant Surge Tank Pressure Cap
The coolant surge tank
pressure cap must be fully
installed on the coolant
surge tank.
Notice:Your pressure cap is a pressure-type cap
and must be tightly installed to prevent coolant loss
and possible engine damage from overheating.
See“Capacities and Specifications”for more
information.
Engine Overheating
You willfind a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-36. In addition, you will
find a LOW COOLANT, ENGINE OVERHEATED and a
REDUCED ENGINE POWER message in the DIC on
the instrument panel. SeeDriver Information Center
(DIC) on page 3-42.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternatesfiring
groups of cylinders helps prevent engine damage. In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the oil
life system. See“Engine Oil”in the Index.
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If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant message,
can indicate a serious problem. See“Low Coolant”
underDIC Warnings and Messages on page 3-51.
If you get an engine overheat warning with no low
coolant message, but see or hear no steam, the problem
may not be too serious. Sometimes the engine can
get a little too hot when you:
•Climb a long hill on a hot day.
•Stop after high-speed driving.
•Idle for long periods in traffic.
•Tow a trailer. See“Driving on Grades”under
Towing a Trailer on page 4-53.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If your air conditioner is on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.3. If you’re in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving–AUTOMATIC OVERDRIVE (
X)
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn’t come back on, you can drive
normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you’re parked. If you still have the warning,turn off the
engine and get everyone out of the vehicleuntil it
cools down. Also, see Overheated Engine Protection
Operating Mode listed previously in this section.
You may decide not to lift the hood but to get service
help right away.
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5. Then replace the
pressure cap. Be sure
the pressure cap is
hand-tight and
fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the fan
speed increases as the clutch more fully engages.
So you may hear an increase in fan noise. This
is normal and should not be mistaken as the
transmission slipping or making extra shifts. It is merely
the cooling system functioning properly. The fan will
slow down when additional cooling is not required and
the clutch disengages.You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
Power Steering Fluid
When to Check Power Steering Fluid
It is not necessary to regularly check power steeringfluid
unless you suspect there is a leak in the system or
you hear an unusual noise. Afluid loss in this system
could indicate a problem. Have the system inspected
and repaired. SeeEngine Compartment Overview
on page 5-12for reservoir location.
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Brakes
Brake Fluid
Your brake master cylinder reservoir isfilled with DOT-3
brakefluid. SeeEngine Compartment Overview on
page 5-12for the location of the reservoir.
There are only two reasons why the brakefluid level in
the reservoir might go down. Thefirst is that the
brakefluid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
thefluid level goes back up. The other reason is
thatfluid is leaking out of the brake system. If it is, you
should have your brake systemfixed, since a leak
means that sooner or later your brakes won’t work well,
or won’t work at all.
So, it isn’t a good idea to“top off”your brakefluid.
Adding brakefluid won’t correct a leak. If you addfluid
when your linings are worn, then you’ll have too
muchfluid when you get new brake linings. You should
add (or remove) brakefluid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brakefluid, it can spill on
the engine. Thefluid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
fluid only when work is done on the brake
hydraulic system. See“Checking Brake Fluid”
in this section.
Refer to the Maintenance Schedule to determine when
to check your brakefluid. SeePart C: Periodic
Maintenance Inspections on page 6-14.
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