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4. Reinstall cap onto DEF tank.
Filling The Def Tank In Cold Climates
Since DEF will begin to freeze at 12°F (-11°C), your
vehicle is equipped with an automatic DEF heating
system. This allows the DEF injection system to operate
properly at temperatures below 12°F (-11°C). If your
vehicle is not in operation for an extended period of time
with temperatures below 12°F (-11°C), the DEF in the
tank may freeze. If the tank is overfilled and freezes, it
could be damaged. Therefore, do not overfill the DEF
tank.
The DEF tank on these vehicles is designed with a large
amount of full reserve. So the level sensor will indicate a
Full reading even before the tank is completely full. To
put it another way, there’s additional storage capacity in
the tank above the Full mark that’s not represented in the
gauge. You may not see any movement in the reading –
even after driving up to 2,000 miles in some cases.The difference this makes varies by vehicle. Heavy-duty
pickup trucks have a 5.7-gallon tank that will display a
Full reading when about 90 percent full. This means that
drivers can consume at least 10 percent of a truly full DEF
tank without seeing any visible change in the gauge
reading. Chassis cabs have a larger 9-gallon tank, and
will display a Full reading when about 75 percent full. So
drivers can consume 25 percent of a truly full DEF tank
without seeing any visible change in the gauge reading.
Extra care should be taken when filling with portable
containers to avoid overfilling. Note the level of the DEF
gauge in your instrument cluster. On pickup applica-
tions, you may safely add a maximum of 2 gallons of DEF
from portable containers when your DEF gauge is read-
ing ½ full. On Chassis Cab applications a maximum of
2 gallons may be added when the DEF gauge is reading
¾ full.
5
STARTING AND OPERATING 257
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The condition of the air cleaner filter is monitored by the
Engine Control Module. The “SERVICE AIR FILTER”
message will display in the Electronic Vehicle Informa-
tion Center (EVIC) or Driver Information Display (DID)
when service is required. Refer to “Electronic Vehicle
Information Center (EVIC)” or “Driver Information Dis-
play (DID)” in “Understanding Your Instrument Panel”
for further information.
The “SERVICE AIR FILTER” message could be displayed
periodically. This is because engine air flow requirements
change based on driving conditions. As the filter becomes
more restrictive and air flow requirements increase the
“SERVICE AIR FILTER” message will be displayed. The
message may not be displayed in subsequent drive cycles
if the same conditions are not met. The air filter element
should be replaced within 250 miles (402 km) from the
first time this message is displayed to ensure proper
engine operation during all driving conditions.CAUTION!
Driving with a restricted air filter can cause engine
damage. Driving in dusty environments for extended
periods will lead to rapid air filter plugging. Action
should be taken as soon as the “SERVICE AIR
FILTER” message is displayed.
If the vehicle experiences a sudden loss of engine power
while being driven in heavy snow or rain, or when
plowing snow, and/or the “SERVICE AIR FILTER” mes-
sage is displayed on the EVIC/DID along with a chime
that repeats every 60 seconds, visually inspect the air
filter for snow/ice build up or extreme water saturation.
If the air filter is not damaged, remove all snow/ice and
reinstall air filter. If the air filter is damaged, replace filter
element.
7
MAINTAINING YOUR VEHICLE 277
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MAINTENANCE SCHEDULE — DIESEL ENGINE
CAUTION!
Failure to perform the required maintenance items
may result in damage to the vehicle.
At Each Stop For Fuel
Check the engine oil level at least 30 minutes after a fully
warmed engine is shut off. Checking the oil level while
the vehicle is on level ground will improve the accuracy
of the oil level reading. Add oil only when the level is at
or below the ADD or MIN mark.
Once A Month
• Inspect the batteries, and clean and tighten the termi-
nals as required. •
Check the fluid levels of the coolant reservoir, brake
master cylinder, and automatic transmission (if
equipped), and add as needed.
At Each Oil Change
• Change the engine oil filter.
• Inspect the exhaust system.
• Inspect engine air filter.
• Check the coolant level, hoses, and clamps.
• Lubricate outer tie rod ends.
Inspection and service should also be performed anytime
a malfunction is observed or suspected. Retain all re-
ceipts.
Oil Change Indicator System — Cummins Diesel
Your vehicle is equipped with an engine oil change
indicator system. This system will alert you when it is
time to change your engine oil by displaying the words
314 MAINTENANCE SCHEDULE
Page 319 of 338
Maintenance Chart — Cummins Diesel Engine
Mileage or time passed
(whichever comes first):
7,500
15,000
22,500
30,000
37,500
45,000
52,500
60,000
67,500
75,000
82,500
90,000
97,500
105,000 112,500
120,000
127,500
135,000
142,500
150,000
Or Months: 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120
Or Kilometers:
12,000
24,000
36,000
48,000
60,000
72,000
84,000
96,000
108,000
120,000
132,000
144,000
156,000
168,000
180,000
192,000
204,000
216,000
228,000
240,000
Change engine oil every 15,000
miles (24 000 km) or six months
or 500 Hours or sooner if
prompted by the oil change indi-
cator system, whichever comes
first. ** XXXXXXXXXXXXXXXXX X XX
Additional Inspections
Check the Diesel Exhaust Fluid
(DEF) tank, refill if necessary. XXXXXXXXXXXXXXXXX X XX
Rotate the tires. X X X X X X X X X X X X X X X X X X X X
8
MAINTENANCE SCHEDULE 317
Page 321 of 338
Mileage or time passed
(whichever comes first):
7,500
15,000
22,500
30,000
37,500
45,000
52,500
60,000
67,500
75,000
82,500
90,000
97,500
105,000 112,500
120,000
127,500
135,000
142,500
150,000
Or Months: 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120
Or Kilometers:
12,000
24,000
36,000
48,000
60,000
72,000
84,000
96,000
108,000
120,000
132,000
144,000
156,000
168,000
180,000
192,000
204,000
216,000
228,000
240,000
Inspect drive belt; replace as nec-
essary. XXXXXX
Inspect wheel bearings. X X X X X
Additional Maintenance
Replace engine fuel filter element. X X X X X X X X X X
Replace chassis mounted fuel
filter element. XXXXXXXX X X
Inspect the front and rear axle
surfaces. If gear oil leakage is
suspected, check the fluid level. If
using your vehicle for police, taxi,
fleet, off-road or frequent trailer
towing change the axle fluid. *
8
MAINTENANCE SCHEDULE 319
Page 322 of 338
Mileage or time passed
(whichever comes first):
7,500
15,000
22,500
30,000
37,500
45,000
52,500
60,000
67,500
75,000
82,500
90,000
97,500
105,000 112,500
120,000
127,500
135,000
142,500
150,000
Or Months: 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120
Or Kilometers:
12,000
24,000
36,000
48,000
60,000
72,000
84,000
96,000
108,000
120,000
132,000
144,000
156,000
168,000
180,000
192,000
204,000
216,000
228,000
240,000
Inspect the transfer case fluid
(4x4), change for any of the fol-
lowing: police, taxi, fleet, or fre-
quent trailer towing. XXXX X
Change the transfer case fluid
(4x4). XX
Change automatic transmission
fluid (AS69RC transmission only). XXXX X
Change the automatic transmis-
sion fluid and sump filter
(AS69RC transmission only). XX
320 MAINTENANCE SCHEDULE
Page 323 of 338
Mileage or time passed
(whichever comes first):
7,500
15,000
22,500
30,000
37,500
45,000
52,500
60,000
67,500
75,000
82,500
90,000
97,500
105,000 112,500
120,000
127,500
135,000
142,500
150,000
Or Months: 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120
Or Kilometers:
12,000
24,000
36,000
48,000
60,000
72,000
84,000
96,000
108,000
120,000
132,000
144,000
156,000
168,000
180,000
192,000
204,000
216,000
228,000
240,000
Change automatic transmission
fluid and filter(s) if using your ve-
hicle for any of the following: po-
lice, fleet, or frequent trailer tow-
ing (68RFE transmission only). XX
Change automatic transmission
fluid and filter(s). X
Change the manual transmission
fluid if using your vehicle for any
of the following: police, fleet, or
frequent trailer towing. XX
Replace Crankcase Ventilation
Filter (CCV). XX
8
MAINTENANCE SCHEDULE 321
Page 324 of 338

Mileage or time passed
(whichever comes first):
7,500
15,000
22,500
30,000
37,500
45,000
52,500
60,000
67,500
75,000
82,500
90,000
97,500
105,000 112,500
120,000
127,500
135,000
142,500
150,000
Or Months: 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120
Or Kilometers:
12,000
24,000
36,000
48,000
60,000
72,000
84,000
96,000
108,000
120,000
132,000
144,000
156,000
168,000
180,000
192,000
204,000
216,000
228,000
240,000
Flush and replace power steering
fluid. X
Flush and replace engine
coolant. *** X
Adjust valve lash clearance. X
Inspection and service should also be performed anytime
a malfunction is observed or suspected. Retain all re-
ceipts.
* Inspect the front and rear axle surfaces every 20,000
miles (32,000 km). If gear oil leakage is suspected, checkthe fluid level. If using your vehicle for police, taxi, fleet,
off-road or frequent trailer towing change the axle fluid
every 20,000 miles (32,000 km).
** Under no circumstances should oil change intervals
exceed 15,000 miles (24 000 km) or six months or 500
Hours, whichever comes first.
322 MAINTENANCE SCHEDULE