gear ratio Ram 2500 2018 User Guide

When to Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting occurs,
push 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.
The “TOW/HAUL Indicator Light” will illuminate in the
instrument cluster to indicate that TOW/HAUL mode has
been activated. Pushing the switch a second time restores
normal operation. Normal operation is always the defaultat engine start-up. If TOW/HAUL mode is desired, the
switch must be pushed each time the engine is started.
WARNING!
Do not use the “TOW/HAUL” feature when driving in
icy or slippery conditions. The increased engine brak-
ing 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 possibly result-
ing in personal injury or death.
Six-Speed Automatic Transmission — 1500 Models
Only (If Equipped)
The transmission gear position display (located in the
instrument cluster) indicates the transmission gear range.
The gear selector is mounted either on the right side of the
steering column (if equipped) or on the console (if
equipped). You must press the brake pedal to move the
gear selector out of PARK (refer to “Brake/Transmission
Shift Interlock System” in this section). To drive, move the
gear selector from PARK or NEUTRAL to the DRIVE
position. Pull the gear selector toward you when shifting
into REVERSE or PARK, or when shifting out of PARK
(column shift only).
TOW/HAUL Switch
306 STARTING AND OPERATING

The electronically-controlled transmission provides a pre-
cise shift schedule. The transmission electronics are self-
calibrating; therefore, the first few shifts on a new vehicle
may be somewhat abrupt. This is a normal condition, and
precision shifts will develop within a few hundred miles
(kilometers).
Only shift from DRIVE to PARK or REVERSE when the
accelerator pedal is released and the vehicle is stopped. Be
sure to keep your foot on the brake pedal when shifting
between these gears.
The transmission gear selector has only PARK, REVERSE,
NEUTRAL, and DRIVE shift positions. Manual downshifts
can be made using the Electronic Range Select (ERS) shift
control. Pressing the ERS (-/+) switches (column shift) or
moving the gear selector to the left or right (-/+) (console
shift) while in the DRIVE position will select the highest
available transmission gear, and will display that gear limit
in the instrument cluster as 1, 2, 3, etc. Refer toElectronic
Range Select (ERS) Operation in this section for further
information. Some models will display both the selected
gear limit, and the actual current gear, while in ERS mode.
Gear Ranges
Do not depress the accelerator pedal when shifting from
PARK or NEUTRAL into another gear range. NOTE:
After selecting any gear range, wait a moment to
allow the selected gear to engage before accelerating. This
is especially important when the engine is cold.
PARK (P)
This range supplements the parking brake by locking the
transmission. The engine can be started in this range.
Never attempt to use PARK while the vehicle is in motion.
Apply the parking brake when exiting the vehicle in this
range.
When parking on a level surface, you may shift the
transmission into PARK first, and then apply the parking
brake.
When parking on a hill, apply the parking brake before
shifting the transmission to PARK, otherwise the load on
the transmission locking mechanism may make it difficult
to move the gear selector out of PARK. As an added
precaution, turn the front wheels toward the curb on a
downhill grade and away from the curb on an uphill grade.
NOTE: On four-wheel drive vehicles be sure that the
transfer case is in a drive position.
When exiting the vehicle, always:
• Apply the parking brake.
6
STARTING AND OPERATING 307

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 “In Case Of Emergency” for
further information.
DRIVE (D)
This range should be used for most city and highway
driving. It provides the smoothest upshifts and downshifts,
and the best fuel economy. The transmission automatically
upshifts through underdrive first and second gears, direct
third gear and overdrive fourth and fifth gears. The DRIVE
position provides optimum driving characteristics under
all normal operating conditions.
To access all six available gears, you must use the Elec-
tronic Range Select (ERS) shift control, described below.
When frequent transmission shifting occurs (such as when
operating the vehicle under heavy loading conditions, in
hilly terrain, traveling into strong head winds, or while
towing a heavy trailer), use the Electronic Range Select
(ERS) shift control (refer to “Electronic Range Select (ERS) Operation” in this section for further information) to select
a lower gear range. Under these conditions, using a lower
gear range will improve performance and extend transmis-
sion life by reducing excessive shifting and heat buildup.
If the transmission temperature exceeds normal operating
limits, the powertrain controller will modify the transmis-
sion shift schedule and expand the range of torque con-
verter clutch engagement. This is done to prevent trans-
mission 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 sig-
nificant additional heat load on the cooling system. Down-
shifting 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.
310 STARTING AND OPERATING

During cold temperatures, transmission operation may be
modified depending on engine and transmission tempera-
ture as well as vehicle speed. This feature improves warm
up time of the engine and transmission to achieve maxi-
mum efficiency. Engagement of both the torque converter
clutch and the top overdrive gear are inhibited until the
transmission fluid is warm (refer to the “Note” under
“Torque Converter Clutch” in this section). During ex-
tremely cold temperatures (-16°F [-27°C] or below), opera-
tion may briefly be limited to first and direct gears only.
Normal operation will resume once the transmission tem-
perature has risen to a suitable level.
Transmission Limp Home Mode
Transmission function is monitored electronically for ab-
normal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. In this mode, the transmission remains
in direct gear regardless of which forward gear is selected.
PARK, REVERSE, and NEUTRAL will continue to operate.
The Malfunction Indicator Light (MIL) may be illuminated.
Limp Home Mode allows the vehicle to be driven to an
authorized dealer for service without damaging the trans-
mission.In the event of a momentary problem, the transmission can
be reset to regain all forward gears by performing the
following steps:
1. Stop the vehicle.
2. Shift the transmission into PARK.
3. Turn the ignition OFF.
4. Wait approximately 10 seconds.
5. Restart the engine.
6. Shift into the desired gear range. If the problem is no
longer detected, the transmission will return to normal
operation.
NOTE: Even if the transmission can be reset, we recom-
mend that you visit your authorized dealer at your earliest
possible convenience. Your authorized dealer has diagnos-
tic equipment to assess the condition of your transmission.
If the transmission cannot be reset, authorized dealer
service is required.
6
STARTING AND OPERATING 311

Electronic Range Select (ERS) Operation —
Six-Speed Transmission (1500 Models Only)
The Electronic Range Select (ERS) shift control allows the
driver to limit the highest available gear when the trans-
mission is in DRIVE. For example, if you set the transmis-
sion gear limit to 4 (fourth gear), the transmission will not
shift above fourth gear, but will shift through the lower
gears normally.
Use of ERS (or TOW/HAUL mode) also enables an addi-
tional underdrive gear which is not normally used during
through-gear accelerations. This additional gear can im-
prove vehicle performance and cooling capability when
towing a trailer on certain grades. In ERS mode, gears 1
though 3 are underdrive gears, and ERS 4 is direct drive.
ERS 5 and 6 (Overdrive gears) are the same as the normal
fourth and fifth gears.
You can switch between DRIVE and ERS mode at any
vehicle speed. When the gear selector is in the DRIVE
position, the transmission will operate automatically, shift-
ing between all available gears. Tapping the ERS (-) switch
(column shift) or tapping the gear selector to the left (-)
(console shift) will activate ERS mode, display the currentgear in the instrument cluster, and set that gear as the top
available gear. For example, if you are in DRIVE and are in
third (direct) gear, when you tap the gear selector/switch
one time in the (-) direction, the display will show 4 (ERS
4 is direct gear). Another tap down (-) will shift the
transmission down to ERS 3 (the added underdrive gear).
Once in ERS mode, tapping (-) or (+) will change the top
available gear.
Column Gear Selector
312 STARTING AND OPERATING

To exit ERS mode, simply hold the gear selector to the right
(+) (console shift) or press and hold the ERS (+) switch
(column shift) until the gear limit display disappears from
the instrument cluster.
WARNING!
Do not downshift for additional engine braking on a
slippery surface. The drive wheels could lose their grip
and the vehicle could skid, causing a collision or
personal injury.NOTE:
To select the proper gear position for maximum
deceleration (engine braking), simply press and hold the
gear selector to the left (-) (console shift) or the ERS (-)
switch down (column shift). The transmission will shift to
the range from which the vehicle can best be slowed down.
CAUTION!
When using ERS for engine braking while descending
steep grades, be careful not to overspeed the engine.
Apply the brakes as needed to prevent engine over-
speed.
Overdrive Operation
The automatic transmission includes an electronically con-
trolled Overdrive (fourth and fifth gears). The transmission
will automatically shift into Overdrive if the following
conditions are present:
• The gear selector is in the DRIVE position,
• The transmission fluid has reached an adequate tem-
perature,
• The engine coolant (antifreeze) has reached an adequate
temperature,
Console Gear Selector
6
STARTING AND OPERATING 313

WARNING!
Do not use the “TOW/HAUL” feature when driving in
icy or slippery conditions. The increased engine brak-
ing 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 possibly result-
ing in personal injury or death.
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 automatically
at calibrated speeds. This may result in a slightly different
feeling or response during normal operation in the upper
gears. When the vehicle speed drops or during some
accelerations, the clutch automatically disengages.
NOTE:
•The torque converter clutch will not engage, and the
transmission will not shift into the top overdrive gear,
until the transmission fluid and engine coolant are warm
[usually after 1 to 3 miles (2 to 5 km) of driving]. Because
top gear is disabled, and 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.
Six-Speed Automatic Transmission — 2500/3500
Models Only
The transmission gear position display (located in the
instrument cluster) indicates the transmission gear range.
The gear selector is mounted on the right side of the
steering column. You must press the brake pedal to move
the gear selector out of PARK (refer to “Brake/
Transmission Shift Interlock System” in this section for
further information). To drive, move the gear selector from
PARK or NEUTRAL to the DRIVE position. Pull the gear
selector toward you when shifting into REVERSE or PARK,
or when shifting out of PARK.
6
STARTING AND OPERATING 315

The electronically-controlled transmission provides a pre-
cise shift schedule. The transmission electronics are self-
calibrating; therefore, the first few shifts on a new vehicle
may be somewhat abrupt. This is a normal condition, and
precision shifts will develop within a few hundred miles
(kilometers).
Only shift from DRIVE to PARK or REVERSE when the
accelerator pedal is released and the vehicle is stopped. Be
sure to keep your foot on the brake pedal when shifting
between these gears.
The transmission gear selector has only PARK, REVERSE,
NEUTRAL, and DRIVE shift positions. Manual downshifts
can be made using the Electronic Range Select (ERS) shift
control. Pressing the ERS (-/+) switches (on the gear
selector) while in the DRIVE position will select the highest
available transmission gear, and will display that gear limit
in the instrument cluster as 1, 2, 3, etc. Refer toElectronic
Range Select (ERS) Operation in this section for further
information. Some models will display both the selected
gear limit, and the actual current gear, while in ERS mode.Gear Ranges
Do not depress the accelerator pedal when shifting from
PARK or NEUTRAL into another gear range.
NOTE: After selecting any gear range, wait a moment to
allow the selected gear to engage before accelerating. This
is especially important when the engine is cold.
PARK (P)
This range supplements the parking brake by locking the
transmission. The engine can be started in this range.
Never attempt to use PARK while the vehicle is in motion.
Apply the parking brake when exiting the vehicle in this
range.
When parking on a level surface, you may shift the
transmission into PARK first, and then apply the parking
brake.
When parking on a hill, apply the parking brake before
shifting the transmission to PARK, otherwise the load on
the transmission locking mechanism may make it difficult
to move the gear selector out of PARK. As an added
precaution, turn the front wheels toward the curb on a
downhill grade and away from the curb on an uphill grade.
316 STARTING AND OPERATING

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 “In Case Of Emergency” for
further information.
DRIVE (D)
This range should be used for most city and highway
driving. It provides the smoothest upshifts and downshifts,
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 driving characteristics
under all normal operating conditions. When frequent transmission shifting occurs (such as when
operating the vehicle under heavy loading conditions, in
hilly terrain, traveling into strong head winds, or while
towing a heavy trailer), use the Electronic Range Select
(ERS) shift control (refer to “Electronic Range Select (ERS)
Operation” in this section for further information) to select
a lower gear range. Under these conditions, using a lower
gear range will improve performance and extend transmis-
sion life by reducing excessive shifting and heat buildup.
If the transmission temperature exceeds normal operating
limits, the powertrain controller will modify the transmis-
sion shift schedule and expand the range of torque con-
verter clutch engagement. This is done to prevent trans-
mission 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 cautionwhen operating a heavily loaded ve-
hicle 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 sig-
nificant additional heat load on the cooling system. Down-
shifting the transmission to the lowest possible gear (when
6
STARTING AND OPERATING 319

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 tempera-
ture as well as vehicle speed. This feature improves warm
up time of the engine and transmission to achieve maxi-
mum efficiency. Engagement of both the torque converter
clutch and the top overdrive gear are inhibited until the
transmission fluid is warm (refer to the “Note” under
“Torque Converter Clutch” in this section). During ex-
tremely cold temperatures (-16°F [-27°C] or below), opera-
tion may briefly be limited to first and direct gears only.
Normal operation will resume once the transmission tem-
perature has risen to a suitable level.
Transmission Limp Home Mode
Transmission function is monitored electronically for ab-
normal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. In this mode, the transmission remains
in fourth gear regardless of which forward gear is selected.
PARK, REVERSE, and NEUTRAL will continue to operate.
The Malfunction Indicator Light (MIL) may be illuminated.Limp Home Mode allows the vehicle to be driven to an
authorized dealer for service without damaging the trans-
mission.
In the event of a momentary problem, the transmission can
be reset to regain all forward gears by performing the
following steps:
1. Stop the vehicle.
2. Shift the transmission into PARK.
3. Turn the ignition OFF.
4. Wait approximately 10 seconds.
5. Restart the engine.
6. Shift into the desired gear range. If the problem is no
longer detected, the transmission will return to normal
operation.
NOTE: Even if the transmission can be reset, we recom-
mend that you visit your authorized dealer at your earliest
possible convenience. Your authorized dealer has diagnos-
tic equipment to assess the condition of your transmission.
If the transmission cannot be reset, authorized dealer
service is required.
320 STARTING AND OPERATING