Engine Oil Life System
(DURAMAX
®Diesel)
When to Change Engine Oil
If your vehicle has the Engine Oil Life System, it
has a computer system that lets you know when to
change the engine oil and filter. This is based
on injection timing, engine load 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 light will
come on. SeeChange Engine Oil Light on
page 176. Change your oil as soon as possible
within the next 600 miles (1 000 km) or 30 hours of
engine operation, whichever occurs first. 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 15,000 miles (24 000 km),
or 150 hours of engine operation, whichever
occurs first, since your last oil change. Remember
to reset the oil life system whenever the oil is
changed.
How to Reset the Engine Oil Life
System
The Engine Oil Life System calculates when to
change your engine oil and filter 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
change your oil prior to a change engine oil light
being turned on, reset the system.
278
Engine Coolant (Gas and
DURAMAX
®/Isuzu Engines)
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 288.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.
Notice:Using coolant other than
DEX-COOL
®may cause premature engine,
heater core or radiator corrosion. In addition,
the engine coolant may require changing
sooner, at 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any
repairs would not be covered by your
warranty. Always use DEX-COOL
®
(silicate-free) coolant in your vehicle.
284
Scheduled Maintenance
Supplements
If your vehicle has a Caterpillar®diesel engine,
your owner’s manual is supplemented by the
Caterpillar
®Diesel Engine Operation &
Maintenance Manual. If your vehicle has an
Allison Transmission
®, your owner’s manual is
supplemented by an Allison Transmission®
Operator’s Manual. Always refer to these manuals
for related maintenance services.
Scheduled Maintenance
The services shown in this schedule up to
100,000 miles (166 000 km) should be repeated
after 100,000 miles (166 000 km) at the same
intervals for the life of this vehicle. The services
shown after 100,000 miles (166 000 km) should
be repeated at the same miles (km) after
those intervals for the life of this vehicle.Gasoline engine vehicles and some DURAMAX
®
diesel and Isuzu 6H diesel engine vehicles have a
computer that lets you know when to change the
engine oil. This is not based on mileage, but on
engine operation and engine temperature. When
the computer has calculated that the oil needs
changing, the Engine Oil Life System will indicate
that a change is necessary. SeeEngine Oil Life
System (Gasoline Engine) on page 276orEngine
Oil Life System (DURAMAX
®Diesel) on page 278
orEngine Oil Life System (Caterpillar®Diesel
Engine) on page 279.
The “Footnotes” at the end of this Maintenance
Schedule further explain maintenance services.
SeeService Publications Ordering Information
on page 415.
100 Miles (160 km)
❑Wheel stud nut service.(36)
1,000 Miles (1 600 km)
❑Wheel stud nut service.(36)
❑Rear axle air shift motor service.(10)
363
E
Electrical System
Add-On Equipment................................... 340
Fuses and Circuit Breakers...................... 341
Fusible Links............................................ 341
Headlamp Wiring..................................... 341
Instrument Panel Fuse Block................... 342
Power Windows and Other Power
Options................................................. 341
Underhood Fuse Block............................. 344
Windshield Wiper Fuses........................... 341
Engine
Air Cleaner/Filter...................................... 280
Alarm and Automatic Shutdown................ 104
Battery..................................................... 304
Change Engine Oil Light.......................... 176
Check and Service Engine Soon Light..... 174
Checks Before Operating......................... 109
Coolant...........................................284, 287
Coolant Heater......................................... 111
Coolant Temperature Gage...................... 173
Diesel Engine Exhaust Brake................... 112
Drive Belt Routing.................................... 355
Exhaust................................................... 131
Exhaust Restrictor.................................... 108
Fan Breakage.......................................... 250Engine (cont.)
Fan Noise................................................ 294
High Idle System..................................... 106
Oil ...................................................268, 272
Oil Life System.......................276, 278, 279
Overheating............................................. 288
Overspeed Warning Light......................... 177
Reduced Power Light............................... 179
Shutdown Warning Light.......................... 177
Speed Limiter.......................................... 164
Starter Over-Crank Protection.................... 97
Starting Your Diesel................................. 100
Starting Your Gasoline............................... 97
Entry Lighting.............................................. 154
Event Data Recorders (EDR)...................... 409
Exhaust Brake Indicator Light...................... 178
Exhaust Restrictor....................................... 108
Extender, Safety Belt..................................... 41
Exterior Lamps............................................ 150
F
Filter
Engine Air Cleaner................................... 280
Filter Minder Gage...................................... 182
Finish Damage............................................ 338
Fixed Mast Antenna.................................... 204
421
Flashers, Hazard Warning........................... 142
Flat Tire...................................................... 330
Fluid
Automatic Transmission............................ 282
Manual Transmission................................ 283
Power Steering........................................ 295
Windshield Washer.................................. 296
Four-Wheel Drive...............................119, 312
Front Axle................................................... 313
Front Wheel Bearings with Oil-Filled Hubs ... 319
Fuel............................................................ 251
Additives.................................................. 252
Diesel Engine Fuel................................... 253
Filling a Portable Fuel Container.............. 266
Filling Your Tank...................................... 264
Filter........................................................ 317
Filter Replacement................................... 263
Fuels in Foreign Countries....................... 264
Gage....................................................... 181
Gasoline Octane...................................... 251
Gasoline Specifications............................ 251
Primary Filter and Water Separator.......... 317
Running Out of Fuel................................ 262
Secondary Filter and Water Separator/
Heater.................................................. 318
Very Cold Weather Operation................... 256
Water in Fuel........................................... 256Fuel (cont.)
Water in Warning Light............................ 182
What Fuel to Use.................................... 253
Fuses
Fuses and Circuit Breakers...................... 341
Instrument Panel Fuse Block................... 342
Underhood Fuse Block............................. 344
Windshield Wiper..................................... 341
G
Gage
Air Pressure............................................. 183
Check Gages Warning Light..................... 180
Engine Coolant Temperature.................... 173
Filter Minder............................................ 182
Fuel......................................................... 181
Hourmeter................................................ 183
Oil Pressure............................................. 175
Speedometer........................................... 163
Tachometer.............................................. 163
Transmission Temperature........................ 178
Voltmeter Gage........................................ 168
Gasoline
Octane..................................................... 251
Specifications........................................... 251
Gasoline Engine, Starting.............................. 97
GM Mobility Reimbursement Program.......... 407
422