engine light Ram 2500 2018 Service Manual

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

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 default
at 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.
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 to sixth gear, until the trans-
mission fluid and engine coolant are warm [usually after
1 to 3 miles (2 to 5 km) of driving]. Because sixth gear is
disabled, and engine speed is higher when the torque
converter clutch is not engaged, it may seem as if the
TOW/HAUL Switch
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STARTING AND OPERATING 323

This transfer case is intended to be driven in the 2H
position for normal street and highway conditions such as
dry, hard surfaced roads.
When additional traction is required, the 4H and 4L
positions can be used to lock the front and rear driveshafts
together and force the front and rear wheels to rotate at the
same speed. This is accomplished by simply moving the
gear selector to the desired positions once the appropriate
speed and gear requirements are met, refer to “Shifting
Procedure – Manually Shifted Transfer Case” in this section
for further information.
The 4H and 4L positions are intended for loose, slippery
road surfaces only. Driving in the 4H and 4L positions on
dry, hard surfaced roads may cause increased tire wear and
damage to the driveline components.
The “Transfer Case Position Indicator Light” in the instru-
ment cluster will alert the driver that the vehicle is in
four-wheel drive and that the front and rear driveshafts are
locked together. This light will illuminate when the transfer
case is shifted into either the 4H or 4L position. There is no
light for the 2H or NEUTRAL positions on some models.When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H positions at
a given road speed. Take care not to overspeed the engine
and do not exceed 25 mph (40 km/h).
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference will adversely affect shifting and can cause
damage to the drivetrain.
NOTE:
Do not attempt to make a shift while only the front
or rear wheels are spinning, as this can cause damage to
driveline components.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
NOTE: Delayed shifts out of four-wheel drive may be
experienced due to uneven tire wear, low or uneven tire
pressures, excessive vehicle loading, or cold temperatures.
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STARTING AND OPERATING 325

The 4WD LOCK and 4WD LOW positions are designed for
loose, slippery road surfaces only. Driving in the 4WD
LOCK and 4WD LOW positions on dry hard surfaced
roads may cause increased tire wear and damage to the
driveline components.
NOTE:The transfer case NEUTRAL button is located on
the lower left hand corner of the 4WD Control Switch. The
transfer case NEUTRAL position is to be used for recre-
ational towing only. Refer to “Recreational Towing” in
“Starting And Operating” for further information.
Transfer Case Position Indicator Lights
The Transfer Case Position Indicator Lights (4WD and
4LOW) are located in the instrument cluster and indicate
the current and desired transfer case selection. When you
select a different transfer case position, the indicator lights
will do the following:
If All Of The Following Shift Conditions Are Met:
1. The current position indicator light will turn OFF.
2. The selected position indicator light will flash until the transfer case completes the shift.
3. When the shift is complete, the indicator light for the selected position will stop flashing and remain ON. If One Or More Of The Following Shift Conditions Are
Not Met:
1. The indicator light for the current position will remain
ON.
2. The newly selected position indicator light will continue to flash.
3. The transfer case will notshift.
NOTE: Before retrying a selection, make certain that all
the necessary requirements for selecting a new transfer
case position have been met. To retry the selection, turn the
control switch back to the current position, wait five
seconds, and retry selection. To find the shift requirements,
refer to the Shifting Procedure for your transfer case,
located in this section.
The “SVC 4WD Warning Light” monitors the electronic
shift four-wheel drive system. If this light remains on after
engine start up or illuminates during driving, it means that
the four-wheel drive system is not functioning properly
and that service is required.
6
STARTING AND OPERATING 329

WARNING!
Always engage the parking brake when powering
down the vehicle if the “SVC 4WD Warning Light” is
illuminated. Not engaging the parking brake may
allow the vehicle to roll, which may cause personal
injury.
NOTE: Do not attempt to make a shift while only the front
or rear wheels are spinning, as this can cause damage to
driveline components.
When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD or
4WD LOCK positions at a given road speed. Take care not
to overspeed the engine and do not exceed 25 mph
(40 km/h).
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference in tire size can cause damage to the
drivetrain.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
Shifting Procedure
NOTE:
• If any of the requirements to select a new transfer case
position have not been met, the transfer case will not
shift. The position indicator light for the previous posi-
tion will remain ON and the newly selected position
indicator light will continue to flash until all the require-
ments for the selected position have been met. To retry a
shift: return the control switch back to the original
position, make certain all shift requirements have been
met, wait five seconds and try the shift again.
• If all the requirements to select a new transfer case
position have been met, the current position indicator
light will turn OFF, the selected position indicator light
will flash until the transfer case completes the shift.
When the shift is complete, the position indicator light
for the selected position will stop flashing and remain
ON.
2WD To 4WD LOCK
Rotate the 4WD control switch to the desired position.
Shifts between 2WD and 4WD LOCK can be done with the
vehicle stopped or in motion. With the vehicle in motion,
330 STARTING AND OPERATING

the transfer case will engage/disengage faster if you mo-
mentarily release the accelerator pedal after turning the
control switch. If the vehicle is stopped, the ignition switch
must be in the ON position with the engine either running
or off. This shift cannot be completed if the ignition switch
is in the ACC position.
NOTE:The four-wheel drive system will not allow shifts
between 2WD/4WD LOCK if the front and/or rear wheels
are spinning (no traction). In this situation, the selected
position indicator light will flash and the original position
indicator light will remain ON. At this time, reduce speed
and stop spinning the wheels to complete the shift.
2WD Or 4WD LOCK To 4WD LOW
NOTE: When shifting into or out of 4WD LOW some gear
noise may be heard. This noise is normal and is not
detrimental to the vehicle or occupants.
Shifting can be performed with the vehicle rolling 2 to
3 mph (3 to 5 km/h) or completely stopped. You can use
either of the following procedures:
Preferred Procedure
1. With the engine running, slow the vehicle to 2 to 3 mph (3 to 5 km/h). 2. Shift the transmission into NEUTRAL.
3. While still rolling, rotate the transfer case control switch
to the desired position.
4. After the desired position indicator light is ON (not flashing), shift the transmission back into gear.
Alternate Procedure
1. Bring the vehicle to a complete stop.
2. With the ignition switch in the ON position and the engine running, shift the transmission into NEUTRAL.
3. Rotate the transfer case control switch to the desired position.
4. After the desired position indicator light is ON (not flashing), shift the transmission back into gear.
NOTE:
• If Steps 1 or 2 of either the Preferred or Alternate
Procedure are not satisfied prior to attempting the shift,
then the desired position indicator light will flash con-
tinuously while the original position indicator light is
ON, until all requirements have been met.
• The ignition switch must be in the ON position for a
shift to take place and for the position indicator lights to
6
STARTING AND OPERATING 331

Transfer Case Position Indicator Lights
The Transfer Case Position Indicator Lights (4WD, 4LOW,
and 4WD AUTO) are located in the instrument cluster and
indicate the current and desired transfer case selection.
When you select a different transfer case position, the
indicator lights will do the following:
If All Of The Following Shift Conditions Are Met:
1. The current position indicator light will turn OFF.
2. The selected position indicator light will flash until thetransfer case completes the shift.
3. When the shift is complete, the indicator light for the selected position will stop flashing and remain ON.
If One Or More Of The Following Shift Conditions Are
Not Met:
1. The indicator light for the current position will remain ON.
2. The newly selected position indicator light will continue to flash.
3. The transfer case will notshift. NOTE:
Before retrying a selection, make certain that all the
necessary requirements for selecting a new transfer case
position have been met. To retry the selection, turn the
control switch back to the current position, wait five
seconds, and retry selection. To find the shift requirements,
refer to the Shifting Procedure for your transfer case,
located in this section.
The “SVC 4WD Warning Light” monitors the electronic
shift four-wheel drive system. If this light remains on after
engine start up or illuminates during driving, it means that
the four-wheel drive system is not functioning properly
and that service is required.
WARNING!
Always engage the parking brake when powering
down the vehicle if the “SVC 4WD Warning Light” is
illuminated. Not engaging the parking brake may
allow the vehicle to roll which may cause personal
injury or death.
NOTE: Do not attempt to make a shift while only the front
or rear wheels are spinning. This could cause damage to
driveline components.
334 STARTING AND OPERATING

When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD, 4WD
AUTO or 4WD LOCK positions at a given road speed. Take
care not to overspeed the engine and do not exceed 25 mph
(40 km/h).
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference in tire size can cause damage to the
drivetrain.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
WARNING!
You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the NEU-
TRAL position without first fully engaging the park-
ing brake. The transfer case NEUTRAL position disen-
gages both the front and rear drive shafts from the
powertrain and will allow the vehicle to roll, even if
the transmission is in PARK. The parking brake
should always be applied when the driver is not in the
vehicle.
Shifting Procedure
NOTE:
•If any of the requirements to select a new transfer case
position have not been met, the transfer case will not
shift. The position indicator light for the previous posi-
tion will remain ON and the newly selected position
indicator light will continue to flash until all the require-
ments for the selected position have been met. To retry a
shift: return the control switch back to the original
position, make certain all shift requirements have been
met, wait five seconds and try the shift again.
• If all the requirements to select a new transfer case
position have been met, the current position indicator
light will turn OFF, the selected position indicator light
will flash until the transfer case completes the shift.
When the shift is complete, the position indicator light
for the selected position will stop flashing and
remain ON.
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STARTING AND OPERATING 335

If One Or More Of The Following Shift Conditions Are
Not Met:
1.
The indicator light for the current position will remain ON.
2. The newly selected position indicator light will continueto flash.
3. The transfer case will notshift.
NOTE: Before retrying a selection, make certain that all the
necessary requirements for selecting a new transfer case
position have been met. To retry the selection, push the
current position, wait five seconds, and retry selection. To
find the shift requirements, refer to the Shifting Procedure
for your transfer case, located in this section.
The “SVC 4WD Warning Light” monitors the electronic
shift four-wheel drive system. If this light remains on after
engine start up or illuminates during driving, it means that
the four-wheel drive system is not functioning properly
and that service is required.
WARNING!
Always engage the parking brake when powering
down the vehicle if the “SVC 4WD Warning Light” is
(Continued)
WARNING! (Continued)
illuminated. Not engaging the parking brake may
allow the vehicle to roll which may cause personal
injury or death.
NOTE: Do not attempt to make a shift while only the front
or rear wheels are spinning. This could cause damage to
driveline components.
When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD, 4WD
or 4WD LOCK positions at a given road speed. Take care
not to overspeed the engine and do not exceed 25 mph
(40 km/h).
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference in tire size can cause damage to the
drivetrain.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
338 STARTING AND OPERATING

indicate the current and desired transfer case selection.
When you select a different transfer case position, the
indicator lights will do the following:
If All Of The Following Shift Conditions Are Met:
1. The current position indicator light will turn OFF.
2. The selected position indicator light will flash until thetransfer case completes the shift.
3. When the shift is complete, the indicator light for the selected position will stop flashing and remain ON.
If One Or More Of The Following Shift Conditions Are
Not Met:
1. The indicator light for the current position will remain ON.
2. The newly selected position indicator light will continue to flash.
3. The transfer case will notshift.
NOTE: Before retrying a selection, make certain that all the
necessary requirements for selecting a new transfer case
position have been met. To retry the selection, push the
current position, wait five seconds, and retry selection. To find the shift requirements, refer to the
Shifting Procedure
for your transfer case, located in this section.
The “SVC 4WD Warning Light” monitors the electronic
shift four-wheel drive system. If this light remains on after
engine start up or illuminates during driving, it means that
the four-wheel drive system is not functioning properly
and that service is required.
WARNING!
Always engage the parking brake when powering
down the vehicle if the “SVC 4WD Warning Light” is
illuminated. Not engaging the parking brake may
allow the vehicle to roll which may cause personal
injury or death.
NOTE: Do not attempt to make a shift while only the front
or rear wheels are spinning. This could cause damage to
driveline components.
When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD, 4WD
AUTO or 4WD LOCK positions at a given road speed. Take
care not to overspeed the engine and do not exceed 25 mph
(40 km/h).
342 STARTING AND OPERATING