Diesel Particulate Filter (Diesel
Engine)
Your vehicle has a Diesel Particulate Filter (DPF) as
part of the exhaust system to reduce vehicle emissions.
The DPF requires a unique exhaust tailpipe with an
exhaust cooler. The exhaust cooler mixes air with the
exhaust at the tailpipe. This lowers the exhaust
temperature before it leaves the tailpipe.
The DPF, the tailpipe, or other exhaust system
components must not be altered. The area where the
exhaust cooler connects to the tailpipe should be
inspected, especially the area where the fresh air enters
the cooler. Make sure the openings are not restricted
or plugged with mud or dirt which could inhibit exhaust
gas cooling. See “Exhaust System Inspection” under
At Least Twice a Year on page 6-27.The DPF will regenerate (self-clean) itself as part of
normal operation. During regeneration, the green DPF
indicator is lit and you will notice a difference in
engine noise and engine speed, but this is normal. The
Engine Control Module (ECM) controls this function
based on several factors including the amount of fuel
consumed, hours of engine operation and miles driven.
Notice:Use of diesel fuel other than Ultra Low
Sulfur Diesel (15 ppm sulfur maximum) or engine oil
other than low ash CJ-4 oil will cause permanent
damage to the DPF and related components.
This damage would not be covered by your
warranty.
Your DPF equipped vehicle has specific fuel and engine
oil requirements. SeeWhat Fuel to Use on page 5-9
andEngine Oil (Caterpillar
®Diesel Engine) on
page 5-23orEngine Oil (Gasoline Engine) on page 5-24
orEngine Oil (DURAMAX
®Diesel Engine) on page 5-28
orEngine Oil (Isuzu Diesel Engine) on page 5-32to
make sure you use the required fuel and engine oil.
2-46
Exhaust Brake Indicator Light.........................3-40
Differential Lock Indicator Light.......................3-40
Reduced Engine Power Light.........................3-41
Highbeam On Light.......................................3-41
Daytime Running Lamps (DRL) Indicator
Light........................................................3-41
Low Washer Fluid Warning Light.....................3-42
Power Take-Off Light....................................3-42
Check Gages Warning Light...........................3-42
Fuel Gage...................................................3-43
Water in Fuel Warning Light...........................3-44
Change Fuel Filter Warning Light....................3-44Diesel Particulate Filter Warning Light..............3-45
Air Filter Restriction Indicator..........................3-45
Air Pressure Gage........................................3-46
Hourmeter Gage...........................................3-46
Audio System(s).............................................3-47
Setting the Clock..........................................3-48
Radio(s)......................................................3-48
Theft-Deterrent Feature..................................3-57
Radio Reception...........................................3-58
Fixed Mast Antenna......................................3-58
Chime Level Adjustment................................3-58
Section 3 Instrument Panel
3-2
Water in Fuel Warning Light
This light is located above
the climate controls in the
center of the instrument
panel.
If your vehicle has the 6.6L DURAMAX
®or a
Caterpillar®diesel engine, this light will come on to
warn you that there is water in the fuel system.
For more information on how this light works, seeWater
in Fuel on page 5-12.
Change Fuel Filter Warning Light
For vehicles with this light,
it is located in the center of
the instrument panel.
If your vehicle has the DURAMAX
®6.6L engine, this
light will come on when the fuel filter needs to be
changed. If your vehicle has the Isuzu 6H 7.8L L6 diesel
engine, this light will come on when water is detected
in the fuel system and when the fuel filter needs to
be changed. SeeFuel Filter Replacement on page 5-18
andWater in Fuel on page 5-12for more information.
3-44
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
Four-Wheel Drive............................................5-73
Front Axle......................................................5-74
Noise Control System.....................................5-75
Tampering with Noise Control System
Prohibited.................................................5-75
Bulb Replacement..........................................5-76
Windshield Wiper Blade Replacement..............5-76
Other Service Items........................................5-78
Fuel Filter....................................................5-78
Primary Fuel Filter and Water Separator..........5-79
Secondary Fuel Filter and Water Separator/
Heater (Caterpillar
®Diesel).........................5-80
Front Wheel Bearings with
Oil-Filled Hubs..........................................5-81
Tires..............................................................5-82
Inflation - Tire Pressure.................................5-82
Wheel Loading.............................................5-83
Dual Tire Operation.......................................5-84
When It Is Time for New Tires.......................5-84
Buying New Tires.........................................5-85
Wheel Alignment and Tire Balance..................5-86Tightening the Wheel Nuts.............................5-86
Wheel Replacement......................................5-90
If a Tire Goes Flat........................................5-92
Appearance Care............................................5-94
Interior Cleaning...........................................5-94
Fabric/Carpet...............................................5-95
Instrument Panel, Vinyl, and Other Plastic
Surfaces..................................................5-96
Care of Safety Belts......................................5-96
Weatherstrips...............................................5-96
Washing Your Vehicle...................................5-97
Cleaning Exterior Lamps/Lenses.....................5-97
Finish Care..................................................5-97
Windshield and Wiper Blades.........................5-98
Aluminum or Chrome-Plated Wheels
and Trim..................................................5-98
Tires...........................................................5-99
Sheet Metal Damage.....................................5-99
Finish Damage.............................................5-99
Underbody Maintenance...............................5-100
Chemical Paint Spotting...............................5-100
Vehicle Care/Appearance Materials................5-100
Section 5 Service and Appearance Care
5-2
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
Other Service Items
Fuel Filter
Fuel Filter/Pressure Regulator
(Gasoline Engines)
The steel fuel filter/pressure regulator is located near
the engine compartment on the driver’s side frame rail.
If your vehicle has a rear steel fuel tank, the fuel
filter/pressure regulator is located near the rear fuel tank,
on the driver’s side frame rail. SeeScheduled
Maintenance on page 6-5for recommended service
intervals.
If your vehicle is equipped with the optional Davco
spin-on type filter, it is located on the driver’s side
frame rail.
Fuel Filter (Diesel Engines)
If you have a diesel engine, your fuel filter is located in
the engine compartment on the driver’s side of the
vehicle, or along the driver’s side frame rail. See “Fuel
Filter Replacement” earlier in this section for further
information.
Also seeScheduled Maintenance on page 6-5for
recommended service intervals.
5-78