Page 269 of 528

²Up Steep Hills Ð
select a lower transmission gear, but try and keep the
torque converter clutch engaged.
²Air Conditioning Ð
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:
²engine misfiring or vibrating severely
²sudden loss of power
²unusual engine noises
²fuel, oil or coolant leaks
²sudden change, outside the normal operating range, in
the engine operating temperature
²excessive smoke
²oil pressure drop
STARTING AND OPERATING 269
5
Page 270 of 528

ENGINE BLOCK HEATER (GAS ENGINES)Ð IF
EQUIPPED
The engine block heater warms engine coolant and
permits quicker starts in cold weather. Connect the cord
to a standard 110-115 volt AC electrical outlet with a
grounded, three-wire extension cord.
The engine block heater cord, on gas engines, is routed
under the hood on the driver side of the vehicle. It has a
removable cap that is located on the driver side of the
Integrated Power Module.
WARNING!
Remember to disconnect the cord before driving.
Damage to the 110-115 volt electrical cord could cause
electrocution.
DIESEL EXHAUST BRAKE (ENGINE BRAKING) ±
IF EQUIPPED
The exhaust brake feature will only function when the
driver turns the exhaust brake switch to the on position.
Once the switch is in the on position and the vehicle is
moving faster than 5 MPH; the exhaust brake will
automatically operate when the driver removes pressure
from the accelerator pedal. Exhaust braking is most
effective when the engine RPM is higher. The automatic
transmission has been programmed to downshift more
aggressively when the exhaust brake is enabled to in-
crease brake performance.
270 STARTING AND OPERATING
Page 271 of 528
WARNING!
Do not use the Exhaust Brake feature when driving
in icy or slippery conditions as the increased engine
braking can cause the rear wheels to slide and the
vehicle to swing around with the possible loss of
vehicle control, which may cause an accident possi-
bly resulting in personal injury or death.
Exhaust Brake Switch
STARTING AND OPERATING 271
5
Page 272 of 528
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:
²vehicle driving control
²reduced brake fade
²longer brake life
²faster cab warm-up.
The exhaust brake feature can also be used to reduce the
engine warm up time. To use the exhaust brake as a
warm-up device, the vehicle must be moving less than 5
MPH, the exhaust brake switch must be in the on
position, and the coolant temperature must below 180 F
and ambient temperature below 60 F.
272 STARTING AND OPERATING
Page 273 of 528

AUTOMATIC TRANSMISSION
CAUTION!
Damage to the transmission may occur if the follow-
ing precautions are not observed:
²Shift into PARK only after the vehicle has come to
a complete stop.
²Shift into or out of REVERSE only after the
vehicle has come to a complete stop and the engine
is at idle speed.
²Do not shift from REVERSE, PARK, or NEUTRAL
into any forward gear when the engine is above
idle speed.
²Before shifting into any gear, make sure your foot
is firmly on the brake pedal.
WARNING!
It is dangerous to shift the selector lever out of ªPº or
ªNº 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.
Automatic Transmission with Overdrive (5 Speed
545RFE) Ð 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
STARTING AND OPERATING 273
5
Page 274 of 528

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, Second, First 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.
ªPº 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!
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.
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.
274 STARTING AND OPERATING
Page 275 of 528

WARNING!
It is dangerous to shift the selector lever out of ªPº or
ªNº 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.
ªRº Reverse
Use this range only after the vehicle has come to a
complete stop.ªNº 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.
ªDº Drive
This position provides all forward gears, including 3rd
gear direct and 4th or 5th gear overdrive (see Overdrive
Operation). Use this range for most city and highway
driving.
ª2º Second
Use this position for driving slowly in heavy city traffic
or on mountain roads where more precise speed control
is desirable. Use it also when climbing long grades, and
for engine braking when descending moderately steep
grades. To prevent excessive engine speed do not exceed
45 mph (72 km/h) in this range.
STARTING AND OPERATING 275
5
Page 276 of 528

ª1º First
Use this position for driving up very steep hills and for
engine braking at low speeds 20 mph (32 km/h) or less
when going downhill. To prevent excessive engine speed,
do not exceed 25 mph (40 km/h) in this range.
NOTE:Use caution when operating a heavily loaded
vehicle in ª2º Second or ª1º First gear selections in high
ambients as torque converter slip can impose significant
additional heat load on the cooling system.
Overdrive Operation
The overdrive automatic transmission contains an elec-
tronically controlled fourth and fifth speed (Overdrive).
The transmission will automatically shift from Drive to
Overdrive if the following conditions are present:
²the transmission selector is in Drive;
²the engine coolant has reached normal operating tem-
perature;
²vehicle speed is above approximately 30 mph (48
km/h);
²the ªTOW HAUL O/D OFFº switch has not been
activated;
²transmission has reached normal operating tempera-
ture.
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.
276 STARTING AND OPERATING