Page 452 of 614

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 that is needed 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 indicates 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 is indicated can vary considerably.
For the oil life system to work properly, the system must
be reset every time the oil is changed.On some vehicles, when the system has calculated
that oil life has been diminished, a CHANGE ENGINE
OIL SOON message comes on to indicate that an oil
change is necessary. See
DIC Warnings and Messages
on page 4‑61. Change the oil as soon as possible
within the next 1 000 km (600 miles). It is possible that,
if 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. For vehicles without the
CHANGE ENGINE OIL SOON message, an oil change
is needed when the OIL LIFE REMAINING percentage
is near 0%. Your dealer 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, the oil must
be changed at 5 000 km (3,000 miles) since the last
oil change. Remember to reset the oil life system
whenever the oil is changed.
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How to Reset the Engine Oil Life
System
The Engine Oil Life System calculates when to
change the engine oil and filter based on vehicle use.
Whenever the oil is changed, reset the system so it
can calculate when the next oil change is required.
If a situation occurs where the oil is changed prior to
a CHANGE ENGINE OIL SOON message coming on,
reset the system.
Always reset the engine oil life to 100% after every oil
change. It will not reset itself. To reset the Engine Oil
Life System on most vehicles:1. Display the OIL LIFE REMAINING on the DIC. If the vehicle does not have DIC buttons, the
vehicle must be in P (Park) to access this display.
See DIC Operation and Displays (With DIC
Buttons)
on page 4‑48or DIC Operation and
Displays (Without DIC Buttons) on page 4‑55.
2. Press and hold the SET/RESET button on the DIC, or the trip odometer reset stem if the vehicle does
not have DIC buttons, for more than five seconds.
The oil life will change to 100%. On all vehicles, the Engine Oil Life System can be reset
as follows:
1. Turn the ignition to ON/RUN with the engine off
2. Fully press the accelerator pedal slowly three times within five seconds.
3. Display the OIL LIFE REMAINING on the DIC. If the display shows 100%, the system is reset.
See DIC Operation and Displays (With DIC
Buttons)
on page 4‑48or DIC Operation and
Displays (Without DIC Buttons) on page 4‑55.
If the vehicle has a CHANGE ENGINE OIL SOON
message and it comes back on when the vehicle is
started and/or the OIL LIFE REMAINING is near 0%,
the Engine Oil Life System has not reset. Repeat the
procedure.
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Page 471 of 614

Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
ENGINE POWER IS REDUCED message is displayed,
an overheat protection mode which alternates firing
groups of cylinders helps prevent engine damage.
In this mode, you will notice a loss in power and engine
performance. This operating mode allows the 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
on
page 6‑18.
Engine Fan Noise
If the 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.
If the vehicle has electric cooling fans, you may hear
the fans spinning at low speed during most everyday
driving. The fans may turn off if no cooling is required.
Under heavy vehicle loading, trailer towing, and/or high
outside temperatures, or if you are operating the air
conditioning system, the fans may change to high
speed and you may hear an increase in fan noise.
This is normal and indicates that the cooling system is
functioning properly. The fans will change to low speed
when additional cooling is no longer required.
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Page 563 of 614

At your dealer, you can be certain that you will receive
the highest level of service available. Your dealer has
specially trained service technicians, uses genuine
replacement parts, as well as, up to date tools and
equipment to ensure fast and accurate diagnostics.
The proper replacement parts, fluids, and lubricants to
use are listed inRecommended Fluids and Lubricants
on page 7‑11andMaintenance Replacement Partson
page 7‑13. We recommend the use of genuine parts
from your dealer.
Rotation of New Tires
To maintain ride, handling, and performance of the
vehicle, it is important that the first rotation service
for new tires be performed when they have 8 000 to
13 000 km (5,000 to 8,000 miles). See Tire Inspection
and Rotation on page 6‑78.
Scheduled Maintenance
When the Change Engine Oil Soon
Message Displays
Change engine oil and filter. See Engine Oilon
page 6‑18. An Emission Control Service.
When the Change Engine Oil Soon message displays,
service is required for the vehicle as soon as possible,
within the next 1 000 km/600 miles. If driving under the
best conditions, the engine oil life system might not
indicate the need for vehicle service for more than
a year. The engine oil and filter must be changed at
least once a year and the oil life system must be reset.
Your dealer has trained service technicians who will
perform this work and reset the system. If the engine
oil life system is reset accidentally, service the vehicle
within 5 000 km/3,000 miles since the last service.
Reset the oil life system whenever the oil is changed.
See Engine Oil Life System on page 6‑20.
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Scheduled Maintenance
ServiceMaintenanceIMaintenance II
Change engine oil and filter. Reset oil life system. • •
Engine coolant level check. ••
Windshield washer fluid level check. ••
Tire inflation pressures check. ••
Tire wear inspection. ••
Rotate tires. ••
Fluids visual leak check. ••
Engine air cleaner filter inspection (vehicles driven in dusty conditions only). ••
Brake system inspection. ••
Steering and suspension inspection. •
Chassis components lubrication. •
Engine cooling system inspection. •
Windshield wiper blades inspection. •
Body components lubrication. •
Restraint system components check. •
Automatic transmission fluid level check. •
Four‐wheel drive only: Transfer case fluid level check. •
Engine air cleaner filter inspection (vehicles not driven in dusty conditions). •
7-8