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 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 light 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.
How to Reset the Change Engine Oil Light
The GM 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.
To reset the change engine oil light, do the following:
1. Turn the ignition key to RUN with the engine off.
2. Fully press and release the accelerator pedal slowly
three times within 10 seconds.
If the change engine oil light flashes for five
seconds, the system is resetting.
3. Turn the key to OFF.
If the change engine oil light comes back on when you
start your vehicle, the engine oil life system has not
reset. Repeat the procedure.
5-24
Hood Latches Check
Check that the hood closes firmly. Check for broken,
damaged, loose or missing parts that might prevent tight
latching. Make sure the secondary latch (if equipped)
keeps the hood from opening all the way when the
primary latch is released.
Fluid Leaks Check
Check for fuel, coolant, oil or other fluid leaks by looking
at the surface beneath the vehicle after it has been
parked for awhile.
Underbody Inspection
Corrosive materials used for ice, snow removal and dust
control can collect on the underbody. If these materials
are not removed, accelerated corrosion (rust) can
occur on underbody parts such as fuel lines, frame, floor
pan and exhaust system. At least every spring, flush
these materials from the underbody with plain
water. Take care to clean well any areas where mud
and other debris can collect. Sediment packed in closed
areas of the frame should be loosened before being
flushed.
Engine Cover Check
Check that the cab’s engine cover and seal (if equipped)
are not torn or damaged. Be sure that the cover is
clamped down firmly to the floor.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specified in Part C.
Underbody Flushing Service
At least every spring, use plain water to flush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
Tractor Protection (Breakaway) Valve
Check
On air brake models, remove, disassemble, clean and
inspect the tractor protection (breakaway) valve.
6-28
Usage Fluid/Lubricant
Manual
Transmission
(Except ZF
6–Speed)Synthetic Manual Transmission Fluid
(GM Part No. U.S. 12345724, in
Canada 10953510).
Manual
Transmission
(ZF 6–Speed)TranSynd™ Synthetic Transmission
Fluid (GM Part No. U.S. 12378515,
in Canada 88900701).
Automatic
TransmissionSee the Allison
Transmission
®Operator’s Manual for
correct transmission fluid.
Key Lock
CylindersMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Chassis
LubricationChassis Lubricant (GM Part No. U.S.
12377985, in Canada 88901242) or
lubricant meeting requirements of
NLGI #2, Category LB or GC-LB.
Front Wheel
Bearing Grease
(Except Oil
Filled Hubs)Wheel bearing lubricant meeting
requirements of NLGI #2, Category
GC or GC-LB (GM Part No. U.S.
1051344, in Canada 993037).
Usage Fluid/Lubricant
Front Wheel
Bearing Grease
with Oil Filled
HubsSAE 75W-90 Synthetic Axle
Lubricant for Medium Duty Trucks
(GM Part No. U.S. 12345841, in
Canada 10953512t).
Rear Axle and
Rear HubsSAE 75W-90 Synthetic Axle
Lubricant for Medium Duty Trucks
(GM Part No. U.S. 12345841, in
Canada 10953512).
Rear Axle Shift
Motor LubricantRefrigerant Oil (GM Part No.U.S.
5416939, in Canada 10953496).
Propshafts and
SplinesWheel bearing lubricant meeting
requirements of NLGI #2, Category
GC or GC-LB (GM Part No. U.S.
1051344, in Canada 993037).
Cab — Door
Hinges and
LatchesMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Weatherstrip
ConditioningDielectric Silicone Grease (GM Part
No. U.S. 12345579, in Canada
992887).
Weatherstrip
SqueaksSynthetic Grease with Teflon,
Superlube (GM Part No. U.S.
12371287, in Canada 10953437).
6-30
I
If No Steam Is Coming From Your Engine..........5-37
If Steam Is Coming From Your Engine...............5-36
If You Are Caught in a Blizzard.........................4-27
If You Are Stuck in Sand, Mud, Ice or Snow.......4-29
If Your Diesel Engine Won’t Start......................2-20
Ignition Positions.............................................2-12
Illuminated Entry.............................................3-16
Infants and Young Children, Restraints...............1-29
Inflation - Tire Pressure...................................5-68
Instrument Panel
Cluster.......................................................3-24
Overview..................................................... 3-4
Switchbank.................................................3-16
Instrument Panel Brightness Control..................3-15
Instrument Panel Fuse Block............................5-88
Inter-Axle Differential Lock Control.....................4-10
Interior Lamps................................................3-15
J
Jump Starting.................................................5-56
K
Key Lock Cylinders Service..............................6-28
Keyless Entry System....................................... 2-3
Keys............................................................... 2-2
L
Lamps
Exterior......................................................3-13
Interior.......................................................3-15
Lamps Check.................................................6-27
Lap Belt........................................................1-22
Lap-Shoulder Belt...........................................1-13
Light
Air Bag Off .................................................3-28
Air Bag Readiness.......................................3-27
Anti-Lock Brake System Warning...................3-34
Brake System Warning.................................3-31
Change Engine Oil......................................3-39
Charging System.........................................3-30
Check Gages Warning.................................3-42
Daytime Running Lamps Indicator..................3-41
8
Rear Seat Outside Passenger Positions
(Crew Cab Models)....................................1-23
Rear Seat Passengers, Safety Belts..................1-23
Rear Wheel Park Brake Burnish Procedure........2-34
Rear Window Defogger....................................3-21
Rearview Mirrors.............................................2-39
Reclining Seatbacks.......................................... 1-4
Reduced Engine Power Light............................3-41
Releasing Air-Operated Parking Brakes..............4-31
Remote Keyless Entry System............................ 2-3
Remote Keyless Entry System, Operation............ 2-4
Replacement Bulbs.........................................5-63
Replacing Brake System Parts..........................5-49
Replacing Restraint System Parts
After a Crash..............................................1-62
Reporting Safety Defects
Canadian Government................................... 7-7
General Motors............................................. 7-7
United States Government.............................. 7-6
Restarting the Diesel Engine While Moving
(Automatic Transmission)..............................2-15
Restarting the Gasoline Engine While Moving
(Automatic Transmission)..............................2-14
Restraint System Check...................................6-25
Checking Your Restraint Systems...................1-61
Replacing Restraint System Parts
After a Crash..........................................1-62Restraint Systems
Checking....................................................1-61
Replacing Parts...........................................1-62
Resynchronization............................................. 2-6
Right Front Passenger Position, Safety Belts......1-22
Rims and Wheels...........................................5-69
Roadside
Assistance Program....................................... 7-4
Rocking Your Vehicle To Get It Out...................4-30
Routing, Engine Drive Belt..............................5-103
Running Out of Fuel........................................5-15
Running Your Engine While You Are Parked.......2-38
S
Safety Belt
Reminder Light............................................3-26
Reminder Tone............................................3-26
Safety Belts
Care of......................................................5-79
Center Passenger Position............................1-22
Driver Position............................................1-13
How to Wear Safety Belts Properly................1-13
Questions and Answers About Safety Belts.....1-12
Rear Seat Passengers.................................1-23
Right Front Passenger Position......................1-22
12