In any particular crash, no one can say whether
an airbag should have inflated simply because
of the damage to a vehicle or because of what
the repair costs were. Inflation is determined
by what the vehicle hits, the angle of the impact,
and how quickly the vehicle slows down.
What Makes an Airbag In ate?
In an impact of sufficient severity, the airbag
sensing system detects that the vehicle is
in a crash. The sensing system triggers a release
of gas from the inflator, which inflates the
airbag. The inflator, airbag, and related hardware
are all part of the airbag modules inside the
steering wheel and in the instrument panel in
front of the right front passenger.
How Does an Airbag Restrain?
In moderate to severe frontal or near-frontal
collisions, even belted occupants can contact
the steering wheel or the instrument panel.
The airbag supplements the protection provided
by safety belts. Airbags distribute the force of
the impact more evenly over the occupant’s upper
body, stopping the occupant more gradually.
But airbags would not help you in many types of
collisions, including rollovers, rear impacts,
and many side impacts, primarily because an
occupant’s motion is not toward those airbags.
Airbags should never be regarded as anything
more than a supplement to safety belts, and then
only in moderate to severe frontal or near-frontal
collisions.
73
Key In the Ignition
Never leave your vehicle with the keys inside, as it
is an easy target for joy riders or thieves. If you
leave the key in the ignition and park your vehicle,
a chime will sound, when you open the driver’s
door. Always remember to remove your key from
the ignition and take it with you. This will lock
your ignition and transaxle. Also, always remember
to lock the doors.
The battery could be drained if you leave the
key in the ignition while your vehicle is parked.
You may not be able to start your vehicle after it has
been parked for an extended period of time.
Engine Starter Over-Crank
Protection
Your vehicle may have an engine starter
over-crank protection system. If the starter motor
overheats and shuts off due to over-cranking,
the motor must cool down before it will reset and
allow starter operation. It can take up to
six minutes before the starter will work again.
Starting the Gasoline Engine
The 8th digit of your Vehicle Identification
Number (VIN) shows the code letter for your
engine. Use this number to verify the type of
engine in your vehicle. SeeVehicle Identi cation
Number (VIN) on page 340. Follow the proper steps
to start the engine.
To start a diesel engine, seeStarting the Diesel
Engine on page 100.
Automatic Transmission
Set the parking brake and move your shift lever to
NEUTRAL (N) or PARK (P), if so equipped. Your
engine will not start in any other position — that is a
safety feature.
Manual Transmission
Set the parking brake, shift to neutral NEUTRAL (N)
and hold the clutch pedal to the floor while starting
the engine.
97
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 363
for 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 363for
recommended service intervals.
Primary Fuel Filter and Water
Separator
If you have a diesel
engine, you may have
this spin-on filter. It
is located on the driver’s
side frame rail.
It has a clear plastic drain bowl at the bottom.
Check the drain bowl occasionally for any water or
particles.
To drain the bowl, do the following:
1. Shut off the engine.
2. Partially open the drain valve at the bottom of
the filter.
SeeEngine Oil (Caterpillar
®Diesel Engine) on
page 268orEngine Oil (Gasoline Engine) on
page 268orEngine Oil (DURAMAX
®/Isuzu Diesel
Engine) on page 272for proper disposal
procedures.
317
30,000 Miles (48 000 km)
❑Gasoline Engine Only: Check engine oil life
system. If engine oil and filter are changed,
reset system. See “Engine Oil (Gasoline
Engine)” in the Index.(2) (8)
❑6.6L DURAMAX
®Diesel Without Engine Oil
Life System Only: Change engine oil and
filter (or every 12 months, or every 750 hours
of engine operation, whichever occurs first).(2)
❑6.6L DURAMAX
®Diesel With Engine Oil
Life System Only: Check oil life system.
If engine oil and filter are changed, reset
system. See “Engine Oil (DURAMAX
®/Isuzu
Diesel)” in the Index.(2) (9)
❑Check fluid levels (or every 3 months,
whichever occurs first).(1) (5)
❑Gasoline Engine: Inspect engine air cleaner
filter. If necessary, replace the filter. If vehicle
is driven in dusty/dirty conditions, inspect
filter at every engine oil change. SeeEngine
Air Cleaner/Filter on page 280for more
information.❑Diesel Engine: Inspect engine air cleaner filter
change indicator. If necessary, replace the
filter. If vehicle is driven in dusty/dirty conditions,
inspect filter change indicator at every engine
oil change. SeeEngine Air Cleaner/Filter
on page 280for more information.
❑DURAMAX
®/Isuzu Diesel Only: Replace fuel
filter (or every 750 hours of engine operation,
whichever occurs first).
❑Chassis lubrication service (or every 6 months,
whichever occurs first).(11)
❑Replace fuel filter(s) (or every 12 months,
whichever occurs first).(2)
❑Steering system service.(12)
❑Front and rear suspension service.(13)
❑Spring-to-axle U-bolts and shackle bolts
service.(15)
❑Exhaust system service (or every 6 months,
whichever occurs first).(2) (3) (16)
❑Wheel bearing (grease type) service (and
whenever hubs are removed).(22) (36)
❑Wheels and tires service.(14)
❑Hydraulic brake service (or every 6 months,
whichever occurs first).(6) (36)
368
❑Isuzu 6H Diesel With Engine Oil Life System
Only: Check oil life system (or every 12 months,
or every 600 hours of engine operation,
whichever occurs first). If engine oil and filter
are changed, reset system. See “Engine Oil
(DURAMAX
®/Isuzu Diesel)” in the Index.(2) (7)
❑Gasoline Engine Only (Vehicles with
GVW greater than 16,000 lbs): Spark plug
service.(2) (25)
❑Check fluid levels (or every 3 months,
whichever occurs first).(1) (5)
❑Gasoline Engine: Inspect engine air cleaner
filter. If necessary, replace the filter. If vehicle
is driven in dusty/dirty conditions, inspect filter
at every engine oil change. SeeEngine Air
Cleaner/Filter on page 280for more information.
❑Diesel Engine: Inspect engine air cleaner filter
change indicator. If necessary, replace the filter.
If vehicle is driven in dusty/dirty conditions,
inspect filter change indicator at every engine
oil change. SeeEngine Air Cleaner/Filter
on page 280for more information.
❑DURAMAX
®/Isuzu Diesel Only: Replace fuel
filter (or every 750 hours of engine operation,
whichever occurs first).❑Chassis lubrication service (or every 6 months,
whichever occurs first).(11)
❑Replace fuel filter(s) (or every 12 months,
whichever occurs first).(2)
❑Inspect door hinge pins and bushings and
replace as necessary.
❑Steering system service.(12)
❑Front and rear suspension service.(13)
❑Spring-to-axle U-bolts and shackle bolts
service.(15)
❑Exhaust system service (or every 6 months,
whichever occurs first).(2) (3) (16)
❑Wheel bearing (grease type) service (and
whenever hubs are removed).(22) (36)
❑Wheels and tires service.(14)
❑Hydraulic brake service (or every 6 months,
whichever occurs first).(6) (36)
❑Parking brake service (or every 6 months,
whichever occurs first).(21)
374
❑Cooling system service. Clean the cooling
system filler cap with clean water, clean
the core, pressure test the cap and the
system for proper pressure capability, and
inspect condition of cooling and heater
hoses and clamps. Replace hoses if cracked,
swollen, or damaged.
❑Replace fuel filter(s) (or every 12 months,
whichever occurs first).(2)
❑Steering system service.(12)
❑Front and rear suspension service.(13)
❑Spring-to-axle U-bolts and shackle bolts
service.(15)
❑Exhaust system service (or every 6 months,
whichever occurs first).(2) (3) (16)
❑Inspect door hinge pins and bushings and
replace as necessary.
❑Wheel bearing (grease type) service (and
whenever hubs are removed).(22) (36)
❑Wheels and tires service.(14)
❑Hydraulic brake service (or every 6 months,
whichever occurs first).(6) (36)
❑Parking brake service (or every 6 months,
whichever occurs first).(21)❑Air brake service (or every 6 months, whichever
occurs first).(32)
❑Air brake automatic slack adjuster service (or
every 500 hours, whichever occurs first).(33)
❑Check air brake relay valve operation and check
for leaks (or every month, or every 300 hours,
whichever occurs first).
❑Clean air brake application valve (or every
3 months, or every 300 hours, whichever
occurs first). Lubricate linkage.
❑Air brake chamber service (or every 2 months,
whichever occurs first).(34)
❑Air brake system valve service (or every
3 months, or every 900 hours, whichever
occurs first).(37)
❑C600, C700, and C800 Gasoline Engines
Only: Engine drive belts service (or every
12 months, whichever occurs first).(17)
❑Thermostatically controlled engine cooling
fan service.(3) (19)
❑Shields and underhood insulation
service.(3) (4) (20)
❑Rear axle air shift motor service.(10)
380
❑Clean air brake application valve (or every
3 months, or every 300 hours, whichever
occurs first). Lubricate linkage.
❑Air brake chamber service (or every 2 months,
whichever occurs first).(34)
100,000 Miles (160 000 km)
❑Diesel Only: Inspect engine drive belt;
replace as necessary.
❑Gasoline Engine Only (Vehicles with
GVW of 16,000 lbs or less): Spark plug
service.(2) (25)
❑Change power steering fluid (or every
36 months, whichever occurs first).(12)
❑Replace power steering reservoir filter element
(or every 24 months, whichever occurs first).
❑Wheel bearing (oil type) service (and whenever
hubs are removed).(22) (36)
❑Except four-wheel drive: Front axle service.(31)
❑Four-wheel drive only: Front axle service.(30)
❑Four-wheel drive only: Transfer case
service.(30)
❑Rear axle service — Eaton
®, Rockwell®,
Spicer®axles (or every 12 months, whichever
occurs first).(30)❑Exhaust brake service, if equipped. Check for
excessive spindle free play and smooth
operation. Lubricate ball joint cap.
❑Inspect air compressor discharge port (or every
6 months or every 1,800 hours, whichever
occurs first).
❑Manual transmission (ZF 6-speed only) fluid
replacement (or every 48 months, whichever
occurs first).
❑Trailer brake hand control valve service (or every
12 months, or every 3,600 hours, whichever
occurs first).(35)
120,000 Miles (192 000 km)
❑C600, C700, and C800 Gasoline Engines Only:
Replace engine drive belts.
❑C400 and C500 Gasoline Engines Only: Engine
drive belts service (or every 12 months,
whichever occurs first).(17)
150,000 Miles (240 000 km)
❑Cooling system service (or every 60 months
since last service, whichever occurs
first).(2) (29)
❑Diesel Engine Only: Inspect engine drive belt;
replace as necessary.
382
(22)= Wheel bearing service:
•Grease type — Clean, inspect, and lubricate
with the proper wheel bearing grease at
designated intervals or when hubs are
removed. SeePart C: Recommended Fluids
and Lubricants on page 397.
•Oil-filled type — Some wheel bearings are
lubricated by axle lubricant. When you
have oil-filled hubs, use lubricant identical
to that used in the axle. Lubricant change
intervals are the same for front and rear
axles. However, you must maintain the proper
oil level between change intervals. See
Front Wheel Bearings with Oil-Filled Hubs
on page 319andPart C: Recommended
Fluids and Lubricants on page 397.
(23)= Check the air intake system installation
to see that gaskets are seated properly and
all hose connections, fasteners, and other
components are tight. Tighten connections
and fasteners or replace parts as required.(24)= Evaporative Control System Service,
if equipped: Check all fuel and vapor lines and
hoses for proper connections and correct routing
(or every 24 months, whichever occurs first).
Replace parts as needed.
(25)= Replace spark plugs. Inspect wires for
damage. Check the wire boot and boot heat
shield fit at spark plugs and coil. Replace parts
as needed.
(26)= Check the fuel tank, fuel cap and fuel lines
for damage which could cause leakage. Inspect
fuel cap for correct sealing ability and any
indications of damage. Check fuel cap gasket
for even filler neck imprint. Replace parts as
needed.
(27)= Check Exhaust Gas Recirculation (EGR)
system as described in the service manual.
SeeService Publications Ordering Information
on page 415.
388