Service............................................................5-4
Accessories and Modifications..........................5-4
California Proposition 65 Warning.....................5-5
California Perchlorate Materials Requirements.....5-5
Doing Your Own Service Work.........................5-6
Engine Fan Breakage.....................................5-6
Fuel................................................................5-7
Gasoline Octane............................................5-7
Gasoline Specifications....................................5-7
Additives.......................................................5-8
Diesel Engine Fuel.........................................5-9
What Fuel to Use...........................................5-9
Very Cold Weather Operation.........................5-12
Water in Fuel...............................................5-12
Running Out of Fuel.....................................5-17
Fuel Filter Replacement.................................5-18
Fuels in Foreign Countries.............................5-19
Filling the Tank............................................5-20
Filling a Portable Fuel Container.....................5-21
Checking Things Under the Hood....................5-22
Hood Latches...............................................5-22
Engine Oil (Caterpillar
®Diesel Engine).............5-23
Engine Oil (Gasoline Engine)..........................5-24
Engine Oil (DURAMAX
®Diesel Engine)............5-28Engine Oil (Isuzu Diesel Engine).....................5-32
Engine Oil Life System (Gasoline Engine)........5-36
Engine Oil Life System (DURAMAX
®/Isuzu
Diesel Engines).........................................5-37
Engine Oil Life System (Caterpillar
®Diesel
Engine)....................................................5-39
Engine Air Cleaner/Filter................................5-39
Automatic Transmission Fluid.........................5-43
Manual Transmission Fluid.............................5-43
Engine Coolant (Caterpillar
®Diesel Engines).....5-44
Engine Coolant (Gas and DURAMAX®/
Isuzu 7.8L L6 Engines)..............................5-44
Coolant Surge Tank Pressure Cap..................5-47
Engine Overheating.......................................5-48
Cooling System............................................5-50
Engine Fan Noise.........................................5-54
Power Steering Fluid.....................................5-54
Windshield Washer Fluid................................5-55
Brakes........................................................5-57
Battery........................................................5-66
Jump Starting...............................................5-67
Rear Axle.......................................................5-72
Rear Axle Shift Motor....................................5-73
Section 5 Service and Appearance Care
5-1
Service
For service and parts needs, visit your dealer/retailer.
You will receive genuine GM parts and GM-trained and
supported service people.
Genuine GM parts have one of these marks:
Accessories and Modi cations
Adding non-dealer accessories to your vehicle can
affect its performance and safety. Such things as,
airbags, braking, stability, ride and handling, emissions
systems, aerodynamics, durability, and electronic
systems like anti-lock brakes, traction control, and
stability control could be affected. Some non-dealer
accessories could even cause malfunction or damage to
parts and systems and would not be covered by the
vehicle warranty.
GM Accessories are designed to complement and
function with other systems on your vehicle. Your GM
dealer can accessorize your vehicle using genuine
GM Accessories. When you go to your GM dealer and
ask for GM Accessories, you will know that GM-trained
and supported service technicians will perform the work
using genuine GM Accessories.
Also, seeAdding Equipment to Your Airbag-Equipped
Vehicle on page 1-59.
5-4
Water In Fuel Light
Problem Recommended Action
Light comes on
intermittently.Drain water from the fuel
filter.
Light stays on at
temperatures above
freezing.Drain the fuel filter
immediately. If no water
can be drained and the
light stays on, see your
dealer/retailer for
assistance.
Light stays on at
temperatures below
freezing.Drain the fuel filter
immediately. If no water
can be drained, water
may be frozen in the
water drain system, or in
the fuel lines. Move the
vehicle to a warm location
to thaw out, and then
drain the filter system.
Light stays on
immediately after
refueling, and a large
amount of water was
possibly pumped into the
fuel tank.Fuel tank purging is
required. See your
dealer/retailer for
assistance.Notice:If you drive when this warning indicator is
on, you can damage your fuel injection system
and your engine. If the indicator comes on right after
you refuel, it means water was pumped into your
fuel tank. Turn off your engine immediately.
Then, have the water drained at once.
To drain water, do the following:
1. Stop and park the vehicle in a safe place. Turn off
the engine and apply the parking brake.
2. Remove the fuel cap.
3. Place a fuel-resistant container under the fuel filter.
The filter drain valve is located on the bottom of the
fuel filter.
If your vehicle has the 6.6L engine, the fuel filter is
located in the engine compartment on the driver’s
side of the vehicle. If your vehicle has either the
7.2L or 7.8L engine, the fuel filters are located in the
engine compartment on the driver’s side of the
vehicle, and on the driver’s side frame rail in front of
the fuel tank.
5-13
4. Turn the ignition key to START for 10 to 15 seconds
at a time until your engine starts. If the engine tries
to run, but does not run smoothly, increase the rpm
a little using the accelerator pedal. This will help
force air through the system.
Your service engine soon light may come on if the
vehicle has run out of fuel. This light may stay on for a
few drive cycles after the condition is corrected, but
will eventually clear itself.
Fuel Filter Replacement
If you want to change the diesel engine fuel filter
yourself, here is how to do it:
{CAUTION:
Diesel fuel is ammable. It could start a re if
something ignites it, and you could be burned.
Do not let it get on hot engine parts, and keep
matches or other ignition sources away.
First, drain any water from the filter by following the
water draining procedure earlier in this section.
Your vehicle’s engine should be off until the end of this
procedure.If your vehicle has the 6.6L engine, the fuel filter is
located in the engine compartment on the driver’s side
of the vehicle. If your vehicle has either the 7.2L or
7.8L engine, the fuel filters are located in the engine
compartment on the driver’s side of the vehicle, and on
the driver’s side frame rail in front of the fuel tank.
1. Apply the parking brake.
2. Unplug the water
sensor wire connected
to the fuel filter and
unscrew the filter
element.
3. Remove the filter element. If there is any dirt on the
filter sealing surface, clean it off. Remove and reuse
the water sensor float switch located on the bottom of
the fuel filter.
4. Install the new filter element.
5-18
5. Reinstall and tighten the filter container and
reconnect the water sensor wire to the filter.
6. Use the fuel filter priming procedure earlier in this
section to prime the fuel filter.
7. Tighten the air bleed valve by turning it clockwise
until hand-tight.
8. Start your engine and let it idle for five minutes.
Check your fuel filter and air bleed valve for
leaks.
How to Reset Fuel Filter Change
Light - DURAMAX®6.6L (LMM) Engine
The engine controller calculates when to change
the fuel filter based on vehicle and fuel use. Anytime
your fuel filter is changed, reset the fuel filter light so the
engine controller can calculate when the next fuel filter
change is required. If a situation occurs where you
change your fuel filter prior to a change fuel filter light
being turned on, reset the fuel filter change light.To reset the Fuel Filter Change light:
1. Turn the ignition key to RUN with the engine off
2. Fully press the accelerator and brake pedals at the
same time for 10 seconds. If the Fuel Filter Change
light flashes for 5 seconds, the system is resetting.
3. Turn the key to OFF
If the Fuel Filter Change light comes back on when you
start your vehicle, the light has not been reset. Repeat
the procedure. SeeChange Fuel Filter Warning Light on
page 3-44for more information.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 your 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.
5-19