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•Up Steep Hills —
select a lower transmission gear, but try and keep the
torque converter locked.
•Air Conditioning —
turn it off temporarily.
Do Not Operate The Engine With Low Oil
Pressure
When the engine is at normal operating temperature, the
minimum oil pressures required are:
Idle 700 to 800 RPM............... 10psi(69kPa)
Full speed and load.............. 30psi(207 kPa)
CAUTION!
If oil pressure falls to less than normal readings, shut
the engine off immediately. Failure to do so could
result in immediate and severe engine damage.
Do Not Operate The Engine With Failed Parts
Practically all failures give some warning before the parts
fail. Be on the alert for changes in performance, sounds,
and visual evidence that the engine requires service.
Some important clues are:
•engine misfiring or vibrating severely
•sudden loss of power
•unusual engine noises
•fuel, oil or coolant leaks
•sudden change, outside the normal operating range, in
the engine operating temperature
•excessive smoke
•oil pressure drop
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DIESEL EXHAUST BRAKE (ENGINE BRAKING) –
IF EQUIPPED
The Exhaust Brake feature is enabled and disabled by
pressing the exhaust brake switch located on the Instru-
ment Panel.NOTE:For optimum braking power it is recommended
to use the Exhaust Brake while in Tow/Haul Mode.
The purpose of the exhaust brake (engine braking) fea-
ture is to supply negative (braking) torque to the engine.
Typically, the engine braking is used for, but not limited
to, vehicle towing applications where vehicle braking can
be achieved by the internal engine power, thereby spar-
ing the mechanical brakes of the vehicle.
Benefits of the exhaust brake are:
•vehicle driving control
•reduced brake fade
•longer brake life
•faster cab warm-up.
Exhaust Brake Switch
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TRANSMISSION SHIFTING
Automatic Transmission with Overdrive (68RFE)
— If Equipped
The gear shift selector display, located in the instrument
panel cluster, indicates the transmission gear range (the
selector is illuminated for night driving). The selector
lever is mounted on the right side of the steering column.
You must depress the brake pedal, to pull the selector
lever out of park (P) position (Brake Interlock System). To
drive, move the selector lever from Park or Neutral to the
desired drive position. Pull the selector lever toward you
when shifting into Reverse, or Park, or when shifting out
of Park.
Gear Ranges
DO NOT race the engine when shifting from Park or
Neutral position into another gear range.“P” Park
This gear position supplements the parking brake by
locking the transmission. The engine can be started in
this range. Never use Park while the vehicle is in motion.
Apply the parking brake when leaving the vehicle in this
range. Always apply parking brake first, then place the
selector in Park position. On 4-wheel drive vehicles be
sure that the transfer case is in a drive position!
WARNING!
Your vehicle could move and injure you and others if
it is not completely in P (Park). Check by trying to
move the gearshift lever back and forth without first
pulling it toward you after you have set it in P. Make
sure it is in Park before leaving the vehicle.
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WARNING!
It is dangerous to shift the selector lever out of “P” or
“N” if the engine speed is higher than idle speed. If
your foot is not firmly on the brake pedal, the vehicle
could accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit someone or
something. Only shift into gear when the engine is
idling normally and when your right foot is firmly on
the brake pedal.
“R” Reverse
Use this range only after the vehicle has come to a
complete stop.“N” Neutral
Shift to Neutral when the vehicle is standing for pro-
longed periods with the engine running. The engine may
be started in this range. Set the parking brake if you must
leave the vehicle.
“D” Drive
Drive range provides underdrive 1st, 2nd and 3rd gears,
direct 4th gear and overdrive 5th and 6th gears. The shift
into overdrive 5th and 6th gear occurs only after the
transmission has completed the shift into 4th gear. No
other movement of the shift mechanism is required to
complete the 4–5 or 5–6 gear shifts.
The 4th and 5th gear upshifts occurs automatically unless
the Tow/Haul mode is enabled.
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Upshifts into both overdrive gears, 5th and 6th, will be
delayed when the transmission fluid temperature is
below 40° F (4.5° C) or above 240° F (115.5° C).
NOTE:Use caution when operating a heavily loaded
vehicle in 2nd or 1st First gear in high ambients as torque
converter slip can impose significant additional heat load
on the cooling system.
WARNING!
Never use Park position on an automatic transmis-
sion as a substitute for the parking brake. Always
apply parking brake fully when parked to guard
against vehicle movement and possible injury or
damage.
Overdrive Operation
The overdrive automatic transmission contains an elec-
tronically controlled 5th and 6th (Overdrive). The trans-
mission will automatically shift from Drive to Overdrive
if the following conditions are present:
•the transmission selector is in Drive;
•the engine coolant has reached normal operating tem-
perature;
•vehicle speed is above approximately 30 mph (48
km/h);
•the “TOW HAUL” switch has not been activated;
•transmission has reached normal operating tempera-
ture.
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NOTE:If the vehicle is started in extremely cold tem-
peratures, the transmission may not shift into Overdrive
and will automatically select the most desirable gear for
operation at this temperature. Normal operation will
resume when the transmission fluid temperature has
risen to a suitable level. Refer also to the Note under
torque converter clutch, later in this section.
If the transmission temperature gets extremely hot, the
transmission will automatically select the most desirable
gear for operation at this temperature. If the transmission
temperature becomes hot enough the TRANS TEMP light
may illuminate. After cool down, the transmission will
resume normal operation.
The transmission will downshift from Overdrive to Drive
if the accelerator pedal is fully depressed at vehicle
speeds above approximately 35 mph (56 km/h).When To Use “TOW HAUL”
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the “TOW HAUL button once to select TOW
HAUL. In TOW HAUL mode, 4th to 5th gear upshifts are
1 — Tow/Haul Switch
2 — AUTO-6 (ERS) Switch 294 STARTING AND OPERATING
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delayed. Shifts into 5th and 6th gear are still allowed
under steady cruise conditions. Closed throttle down-
shifts (for improved engine braking) may occur during
steady braking maneuvers. Pressing the switch a second
time restores normal operation. Normal operation is
always the default at engine start-up.
The “TOW HAUL” light will illuminate in the instrument
cluster to indicate when the switch has been activated. If
the “TOW HAUL” modes are desired, the button must be
pressed each time the engine is started.
Electronic Range Select (ERS) Operation
The Auto–6 Electronic Range Select (ERS) shift control
allows you to move the switch down (-) or up (+) when
the shifter is in the D (Drive) position, allowing the
selection of the desired top gear. For example, if the
driver shifts the transmission into 3rd gear, the transmis-
sion will never shift above 3rd gear, but can shift down to
2nd or 1st gear, when needed.Switching from ERS to D-Mode can be done at any
vehicle speed. To switch from “Drive” mode to “ERS”
mode, press the switch down (-) once. The selected gear
will be maintained as the top gear. To disable ERS, simply
press and hold the switch up (+) until “D” is displayed in
the instrument cluster odometer.
WARNING!
Do not downshift for additional engine braking on a
slippery surface. The drive wheels could lose their
grip and the vehicle could skid.
Screen Display12 3456D
Actual Gear(s)
Allowed1 1-2 1-3 1-4 1-5 1-6 1-6
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NOTE:To select the proper gear position for maximum
deceleration (engine braking), simply press and hold the
switch down (-). The transmission will shift to the range
from which the vehicle can best be slowed down.
Torque Converter Clutch
A feature, designed to improve fuel economy, has been
included in the automatic transmission on your vehicle.
A clutch within the torque converter engages automati-
cally at calibrated speeds. This may result in a slightly
different feeling or response during normal operation in
high gear. When the vehicle speed drops or during
acceleration when the transmission downshifts to second
gear, the clutch automatically disengages.
NOTE:The torque converter clutch will not engage
until the transmission fluid and engine coolant are warm
[usually after 1-3 miles (1.6 - 4.8 km) of driving]. Because
the engine speed is higher when the torque converter
clutch is not engaged, it may seem as if the transmissionis not shifting into Overdrive when cold. This is normal.
Pressing the “TOW/HAUL” button, when the transmis-
sion is sufficiently warm, will demonstrate that the
transmission is able to shift into and out of overdrive.
NOTE:If the vehicle has not been driven in several
days, the first few seconds of operation after shifting the
transmission 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 of shifting from Park into
any other gear position.
Out of Park Sense Alarm — If Equipped
Vehicles equipped with a Diesel Engine and a Automatic
Transmission may be equipped with an Alarm that warns
the customer, upon exiting the vehicle, that the transmis-
sion is not in the Park position. This feature will only be
functional under following conditions:
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