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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.
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
292 STARTING AND OPERATING
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CAUTION!
When using ERS for engine braking while descend-
ing steep grades, be careful not to overspeed the
engine. Apply the brakes as needed to prevent en-
gine overspeed.
Overdrive Operation
The automatic transmission includes an electronically
controlled Overdrive (fifth and sixth gears). The trans-
mission will automatically shift into Overdrive if the
following conditions are present:
•The shift lever is in the DRIVE position.
• The transmission fluid has reached an adequate tem-
perature.
• 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.
296 STARTING AND OPERATING
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NOTE:
•The torque converter clutch will not engage (and
68RFE-equipped trucks will not shift to sixth gear),
until the transmission fluid and engine coolant are
warm [usually after 1 to 3 miles (2 to 5 km) of driving].
Because the engine speed is higher when the torque
converter clutch is not engaged, it may seem as if the
transmission is not shifting properly when cold. This is
normal. Using the Electronic Range Select (ERS) shift
control, when the transmission is sufficiently warm,
will demonstrate that the transmission is able to shift
into and out of Overdrive.
•
If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the transmis-
sion into gear may seem sluggish. This is due to the fluid
partially draining from the torque converter into the
transmission. This condition is normal and will not cause damage to the transmission. The torque converter will
refill within five seconds after starting the engine.
MANUAL TRANSMISSION — IF EQUIPPED
WARNING!
You or others could be injured if you leave the
vehicle unattended without having the parking
brake fully applied. The parking brake should al-
ways be applied when the driver is not in the vehicle,
especially on an incline.
CAUTION!
Never drive with your foot resting on the clutch
pedal, or attempt to hold the vehicle on a hill with the
clutch pedal partially engaged, as this will cause
abnormal wear on the clutch.
298 STARTING AND OPERATING
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NOTE:During cold weather, you may experience in-
creased effort in shifting until the transmission fluid
warms up. This is normal.
Shifting
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.
Shift Pattern
5
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JUMP STARTING
WARNING!
•To prevent personal injury or damage to clothing,
do not allow battery fluid to contact eyes, skin or
fabrics. Do not lean over a battery when connecting
jumper cables or allow cable clamps to touch each
other. Keep open flames or sparks away from
battery vent holes. Always wear eye protection
when working with batteries.
• Do not use a booster battery or any other booster
source that has a greater than 12 Volt system, i.e., do
not use a 24 Volt power source.
NOTE: Replacement batteries should both be of equal
size to prevent damage to the vehicle’s charging system.
Your vehicle is equipped with two 12 Volt batteries. If it
becomes necessary to use a booster battery with jumper cables to start a vehicle’s engine because its batteries are
discharged, the following procedure should be used:
Set the parking brake and place an automatic transmis-
sion in PARK (or NEUTRAL for a manual transmission).
Turn off lights, heater and other electrical loads. Observe
charge indicator (if equipped) in both batteries. If the
indicator (if equipped) is light or yellow on either battery,
replace that battery.
CAUTION!
Use the jump start procedure only when the charge
indicator (if equipped) in both batteries is dark in the
center. Do not attempt jump starting when either
battery charge indicator (if equipped) is bright or
yellow. If the charge indicator (if equipped) has a
green dot in the center, failure to start is not due to a
discharged battery and cranking system should be
checked.
326 WHAT TO DO IN EMERGENCIES
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▫Manual Transmission — If Equipped ........362
▫ Automatic Transmission — If Equipped ......363
▫ Noise Control System Required Maintenance &
Warranty .......................... .366
FLUID CAPACITIES ....................373
FLUIDS, LUBRICANTS AND GENUINE
PARTS ............................. .374
▫ Engine ............................ .374
▫ Chassis ........................... .377
332 MAINTAINING YOUR VEHICLE
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ENGINE COMPARTMENT — 6.7L DIESEL — SIX-SPEED 68RFE (2500/3500 Models)
1 — Battery7 — Washer Fluid Reservoir
2 — Engine Coolant Reservoir 8 — Power Steering Fluid Reservoir
3 — Automatic Transmission Dipstick 9 — Power Distribution Center
4 — Brake Fluid Reservoir 10 — Engine Oil Dipstick
5 — Battery 11 — Engine Oil Fill
6 — Aux Power Distribution Center 12 — Air Cleaner Filter7
MAINTAINING YOUR VEHICLE 333
Page 336 of 406
ENGINE COMPARTMENT — 6.7L DIESEL — SIX-SPEED AS69RC HD (3500/CHASSIS CAB MODELS)
1 — Battery7 — Washer Fluid Reservoir
2 — Engine Coolant Reservoir 8 — Power Steering Fluid Reservoir
3 — Automatic Transmission Dipstick 9 — Power Distribution Center
4 — Brake Fluid Reservoir 10 — Engine Oil Dipstick
5 — Battery 11 — Engine Oil Fill
6 — Aux Power Distribution Center 12 — Air Cleaner Filter
334 MAINTAINING YOUR VEHICLE