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NOTE:Light duty operation such as light trailer towing
or no load operation will extend the time before the
engine is at full efficiency. Reduced fuel economy and
power may be seen at this time.
For additional vehicle break-in requirements, refer to
“Trailer Towing” in “Starting And Operating” of the
Owners Manual. Because of the construction of the Cummins® turbo-
charged diesel engine, engine run-in is enhanced by
loaded operating conditions which allow the engine
parts to achieve final finish and fit during the first 6,000
miles (10 000 km).
148 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE
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If the light remains lit with the engine running, your
vehicle will usually be drivable. However, see an autho-
rized dealer for service as soon as possible. If the light is
flashing when the engine is running, immediate service is
required. You may experience reduced performance, an
elevated/rough idle or engine stall and your vehicle may
require towing.
14. Alternate Trailer Height
This light will illuminate when the air suspension system
is set to the Normal Ride Height setting. For further
information, refer to “Air Suspension System” in “Start-
ing And Operating”.
15. 4 LOWThis light alerts the driver that the vehicle is in
the four-wheel drive LOW mode. The front and
rear driveshafts are mechanically locked to-
gether forcing the front and rear wheels to rotate at the same speed. Low range provides a greater
gear reduction ratio to provide increased torque at the
wheels.
For further information on four-wheel drive operation
and proper use, refer to “Four-Wheel Drive Operation —
If Equipped” in “Starting And Operating”.
16. Speedometer
The speedometer shows the vehicle speed in miles per
hour and/or kilometers per hour (mph/km/h).
17. 4WD AUTO Indicator Light — If Equipped
This light alerts the driver that the vehicle is in
the four-wheel drive auto mode, and the front
axle is engaged, but the vehicle’s power is sent
to the rear wheels. Four-wheel drive will be
automatically engaged when the vehicle senses a loss of
traction.
3
UNDERSTANDING YOUR INSTRUMENT PANEL 157
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1. Main Screen — The inner ring of the display willilluminate in grey under normal conditions, yellow for
non critical warnings, red for critical warnings and
white for on demand information.
2. Audio Information and Submenu Information — Whenever there are submenus available, the position
within the submenus is shown here.
3. Selectable Information (Compass, Temp, Range to Empty, Trip A, Trip B, Average MPG, Trailer Trip
(distance only), Trailer Brake Gain).
4. Air Suspension Status – If Equipped
5. Transmission Gear Position Indicator (PRND) 6. Status Menu Icons
7. Telltales/Indicators
8. 4WD Status
9. Selectable Gauge (Trans Temp, Oil Temp, Oil Life,
Trailer Brake, Current MPG, Fuel Filter Life, Turbo
Boost, Exhaust Brake, Battery Voltage)
10. Main Menu Items (Digital Speedometer, Vehicle Info, Fuel Economy, Trip A, Trip B, Trailer Tow, Audio,
Stored Messages, Screen Setup, Vehicle Settings)
11. Selectable Gauge (Trans Temp, Oil Temp, Oil Life, Trailer Brake, Current MPG, Fuel Filter Life, Turbo
Boost, Exhaust Brake, Battery Voltage)
3
UNDERSTANDING YOUR INSTRUMENT PANEL 189
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WARNING!
Do not coast in NEUTRAL and never turn off the
ignition to coast down a hill. These are unsafe
practices that limit your response to changing traffic
or road conditions. You might lose control of the
vehicle and have a collision.
CAUTION!
Towing the vehicle, coasting, or driving for any other
reason with the transmission in NEUTRAL can cause
severe transmission damage. Refer to “Recreational
Towing” in “Starting And Operating” and “Towing A
Disabled Vehicle” in “What To Do In Emergencies”
for further information.DRIVE (D)
This range should be used for most city and highway
driving. It provides the smoothest upshifts and down-
shifts, and the best fuel economy. The transmission
automatically upshifts through underdrive first, second,
and third gears, direct fourth gear and overdrive fifth and
sixth gears. The DRIVE position provides optimum driv-
ing characteristics under all normal operating conditions.
When frequent transmission shifting occurs (such as
when operating the vehicle under heavy loading condi-
tions, in hilly terrain, traveling into strong head winds, or
while towing heavy trailers), use the Electronic Range
Select (ERS) shift control (refer to “Electronic Range
Select (ERS) Operation” in this section for further infor-
mation) to select a lower gear range. Under these condi-
tions, using a lower gear range will improve performance
and extend transmission life by reducing excessive shift-
ing and heat buildup.
4
STARTING AND OPERATING 237
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If the transmission temperature exceeds normal operat-
ing limits, the powertrain controller will modify the
transmission shift schedule and expand the range of
torque converter clutch engagement. This is done to
prevent transmission damage due to overheating.
If the transmission becomes extremely hot or is in danger
of overheating, the “Transmission Temperature Warning
Light” may illuminate and the transmission may operate
differently until the transmission cools down.
NOTE:Use caution when operating a heavily loaded
vehicle at low speeds (such as towing a trailer up a steep
grade, or in stop-and-go traffic) during hot weather. In
these conditions, torque converter slip can impose a
significant additional heat load on the cooling system.
Downshifting the transmission to the lowest possible
gear (when climbing a grade), or shifting to NEUTRAL
(when stopped in heavy traffic) can help to reduce this
excess heat generation. During cold temperatures, transmission operation may
be modified depending on engine and transmission
temperature as well as vehicle speed. This feature im-
proves warm up time of the engine and transmission to
achieve maximum efficiency. Engagement of the torque
converter clutch is inhibited until the transmission fluid
is warm (refer to the “Note” under “Torque Converter
Clutch” in this section). On Pickup models with 68RFE
transmission, top overdrive gear is also inhibited until
the transmission fluid is warm, and during extremely
cold temperatures (-16°F [-27°C] or below), operation
may briefly be limited to first and direct gears only. On
trucks with AS69RC transmission, fifth and sixth gears
may be inhibited briefly on cold starts below 41°F (5°C),
and during very cold temperatures (-4°F [-20°C] or
below), operation may briefly be limited to third gear
only. During this condition, the ability of the vehicle to
238 STARTING AND OPERATING
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•The engine coolant has reached an adequate tempera-
ture.
• The vehicle speed is sufficiently high.
• The driver is not heavily pressing the accelerator.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the TOW/HAUL switch to activate TOW/
HAUL mode. This will improve performance and reduce
the potential for transmission overheating or failure due
to excessive shifting. When operating in TOW/HAUL
mode, transmission upshifts are delayed, and the trans-
mission will automatically downshift (for engine brak-
ing) when the throttle is closed and/or during steady
braking maneuvers.
The “TOW/HAUL Indicator Light” will illuminate in the
instrument cluster to indicate that TOW/HAUL mode has
been activated. Pressing the switch a second time restores
normal operation. Normal operation is always the default
at engine start-up. If TOW/HAUL mode is desired, the
switch must be pressed each time the engine is started.
TOW/HAUL Switch
242 STARTING AND OPERATING
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Truck models with manual transmission are equipped
with a clutch interlocking ignition system. The clutch
pedal must be fully pressed to start the vehicle.
Fully press the clutch pedal before shifting gears. As you
release the clutch pedal, lightly press the accelerator
pedal.
This transmission has a “creeper” first gear which should
be used to start from a standing position when carrying a
payload or towing a trailer. Damage to the clutch can result
from starting in second or third gear with a loaded vehicle.
An unloaded vehicle may be launched in second gear. Use
each gear in numerical order – do not skip a gear.
NOTE:When loaded, pulling a trailer or on a grade, the
truck should always start in first gear and not skip gears.
Recommended Vehicle Shift Speeds
To utilize your manual transmission efficiently for both
fuel economy and performance, it should be upshifted as
listed in recommended shift speed chart. Shift at the
vehicle speeds listed for acceleration. When heavily
loaded or pulling a trailer these recommended up-shift
speeds may not apply.
Maximum Recommended Up-Shift Speeds
Gear Selection 1 to 2 2 to 33 to 44 to 5 5 to 6
Maximum Speed 7 mph
(11 km/h) 15 mph
(24 km/h) 25 mph
(40 km/h) 40 mph
(64 km/h) 45 mph
(72 km/h)
4
STARTING AND OPERATING 245
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Mileage or time passed (which-ever 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 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. *
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
328 MAINTENANCE SCHEDULE