engine RAM CHASSIS CAB 2007 Repair Manual

ENGINE BLOCK HEATER — 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 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 is enabled and disabled by
pressing the exhaust brake switch located on the Instru-
ment Panel.
Exhaust Brake Switch STARTING AND OPERATING 265
5

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. AUTOMATIC TRANSMISSION
CAUTION!Damage to the transmission may occur if the follow-
ing precautions are not observed:
• Shift into PARK only after the vehicle has come to
a complete stop.
• Shift into or out of REVERSE only after the
vehicle has come to a complete stop and the
engine is at idle speed.
• Do not shift from REVERSE, PARK, or NEUTRAL
into any forward gear when the engine is above
idle speed.
• Before shifting into any gear, make sure your foot
is firmly on the brake pedal.266 STARTING AND OPERATING

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 re-
verse. 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) — 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, 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.
“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! STARTING AND OPERATING 267
5

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. 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 re-
verse. 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.268 STARTING AND OPERATING

“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
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.
“2” 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. “1” 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 “2” Second or “1” 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:
• the transmission selector is in Drive;
• the engine coolant has reached normal operating tem-
perature; STARTING AND OPERATING 269
5

When To Use “TOW HAUL” and “O/D OFF”
Modes
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the “TOW HAUL O/D OFF” button once to
select TOW HAUL. This will improve performance and reduce the potential for transmission overheating or
failure due to excessive shifting. When operating in
“TOW HAUL” mode, 5th gear is disabled and 2-3 and 3-4
shift patterns are modified. Shifts into Overdrive (4th
gear) are allowed during steady cruise (for improved fuel
economy) and automatic closed-throttle downshifts to
3rd gear (for improved braking) will occur during steady
braking. Pressing the “TOW HAUL O/D OFF” button a
second time to select O/D OFF will disable 4th and 5th
gear completely, which should eliminate any excessive
transmission shifting.
The “TOW HAUL” or “O/D OFF” light will illuminate in
the instrument cluster to indicate when the switch has
been activated. Pressing the switch a third time restores
normal operation. If the “TOW HAUL” or “O/D OFF”
modes are desired, the button must be pressed each time
the engine is started.Tow Haul O/D Off Switch STARTING AND OPERATING 271
5

When To Lock Out Overdrive
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent 4–3–4 transmission shifting
occurs, press the “TOW/HAUL” button twice to disable
the overdrive. This will improve performance and reduce
the potential for transmission overheating or failure due
to excessive shifting.
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 transmission
is 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.272 STARTING AND OPERATING

Automatic Transmission (6 Speed AS68RC) — 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, 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.
“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!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. STARTING AND OPERATING 273
5

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.
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 re-
verse. 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
This position provides all forward gears, including 4th
gear direct and 5th or 6th (if equipped) gear overdrive
(see Overdrive Operation). Use this range for most city
and highway driving.
“3” Third
Use this position for driving in slight heavy city traffic or
on mountain roads where more precise speed control is
desirable. Use it also when climbing long grades, and for274 STARTING AND OPERATING

engine braking when descending moderately steep
grades. To prevent excessive engine speed do not exceed
40 mph (64 km/h) in this range.
“2” Second
Use this position for driving on more severe conditions
and lower speeds than “3” third. To prevent excessive
engine speed do not exceed 25 mph (40 km/h) in this
range.
“1” First
Use this position for driving up very steep hills and for
engine braking at low speeds 15 mph (24 km/h) or less
when going downhill. To prevent excessive engine speed,
do not exceed 15 mph (24 km/h) in this range.
NOTE: Use caution when operating a heavily loaded
vehicle in “2” Second or “1” 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 5th and 6th (if equipped) speed
(Overdrive). The transmission 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 38 mph (61
km/h) for 5th gear and 55 mph (89 km/h) for 6th gear;
• the “TOW HAUL O/D OFF” switch has not been
activated;
• transmission has reached normal operating tempera-
ture. STARTING AND OPERATING 275
5