2023 RAM CHASSIS CAB service indicator

104GETTING TO KNOW YOUR INSTRUMENT PANEL
Hood Open Warning Light
This warning light will illuminate when the
hood is ajar/open and not fully closed.
NOTE:If the vehicle is moving, there will also be a single
chime.
Vehicle Security Warning Light —
If Equipped
This light will flash at a fast rate for
approximately 15 seconds when the
vehicle security system is arming, and
then will flash slowly until the vehicle
is disarmed.
Engine Coolant Temperature Warning
Light
This warning light warns of an
overheated engine condition. If the
engine coolant temperature is too high,
this indicator will illuminate and a single
chime will sound. If the temperature reaches the
upper limit, a continuous chime will sound for four
minutes or until the engine is able to cool,
whichever comes first.
If the light turns on while driving, safely pull over
and stop the vehicle. If the Air Conditioning (A/C)
system is on, turn it off. Also, shift the transmission
into NEUTRAL and idle the vehicle. If the temperature reading does not return to normal,
turn the engine off immediately and call for service
Ú
page 335.
Battery Charge Warning Light
This warning light will illuminate when the
battery is not charging properly. If it stays
on while the engine is running, there may
be a malfunction with the charging
system. Contact an authorized dealer as soon as
possible.
This indicates a possible problem with the
electrical system or a related component.
Oil Pressure Warning Light
This warning light will illuminate to
indicate low engine oil pressure. If the
light turns on while driving, stop the
vehicle, shut off the engine as soon as
possible, and contact an authorized dealer. A
chime will sound when this light turns on.
Do not operate the vehicle until the cause is
corrected. This light does not indicate how much oil
is in the engine. The engine oil level must be
checked under the hood.
Oil Temperature Warning Light
This warning light will illuminate to
indicate the engine oil temperature is
high. If the light turns on while driving,
stop the vehicle and shut off the engine as soon as possible. Wait for oil temperature to
return to normal levels.
Electronic Throttle Control (ETC) Warning
Light
This warning light will illuminate to
indicate a problem with the ETC system.
If a problem is detected while the vehicle
is running, the light will either stay on or
flash depending on the nature of the problem.
Cycle the ignition when the vehicle is safely and
completely stopped and the transmission is placed
in the PARK position. The light should turn off. If
the light remains on with the vehicle running, your
vehicle will usually be drivable; however, see an
authorized dealer for service as soon as possible.
NOTE:This light may turn on if the accelerator and brake
pedals are pressed at the same time.
If the light continues to flash when the vehicle is
running, immediate service is required and you
may experience reduced performance, an
elevated/rough idle, or engine stall and your
vehicle may require towing. The light will come on
when the ignition is placed in the ON/RUN or ACC/
ON/RUN position and remain on briefly as a bulb
check. If the light does not come on during starting,
have the system checked by an authorized dealer.

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GETTING TO KNOW YOUR INSTRUMENT PANEL105
Electric Power Steering (EPS) Fault
Warning Light
This warning light will turn on when
there's a fault with the EPS system
Úpage 148.
Trailer Brake Disconnected Warning Light
This warning light will illuminate when the
Trailer Brake has been disconnected
Úpage 181.
Transmission Temperature Warning Light
This warning light will illuminate to warn
of a high transmission fluid temperature.
This may occur with strenuous usage
such as trailer towing. If this light turns
on, stop the vehicle and run the engine at idle or
slightly faster, with the transmission in PARK or
NEUTRAL, until the light turns off. Once the light
turns off, you may continue to drive normally.
Door Open Warning Light
This indicator will illuminate when a door
is ajar/open and not fully closed.
NOTE:If the vehicle is moving there will also be a single
chime.
YELLOW WARNING LIGHTS
Adaptive Cruise Control (ACC) Fault
Warning Light — If Equipped
This warning light will illuminate to
indicate a fault in the ACC system.
Contact a local authorized dealer for
service Ú page 150.
Engine Check/Malfunction Indicator
Warning Light (MIL)
The Engine Check/Malfunction Indicator
Light (MIL) is a part of an Onboard
Diagnostic System called OBD II that
monitors engine and automatic
transmission control systems. This warning light
will illuminate when the ignition is in the ON/RUN
position before engine start. If the bulb does not
come on when turning the ignition switch from OFF
to ON/RUN, have the condition checked promptly.
Certain conditions, such as a loose or missing gas
cap, poor quality fuel, etc., may illuminate the light
after engine start. The vehicle should be serviced if
the light stays on through several typical driving
styles. In most situations, the vehicle will drive
normally and will not require towing.
WARNING!
Continued operation with reduced assist could
pose a safety risk to yourself and others. Service
should be obtained as soon as possible.
WARNING!
If you continue operating the vehicle when the
Transmission Temperature Warning Light is
illuminated you could cause the fluid to boil over,
come in contact with hot engine or exhaust
components and cause a fire.
CAUTION!
Continuous driving with the Transmission
Temperature Warning Light illuminated will
eventually cause severe transmission damage
or transmission failure.
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106GETTING TO KNOW YOUR INSTRUMENT PANEL
When the engine is running, the MIL may flash to
alert serious conditions that could lead to
immediate loss of power or severe catalytic
converter damage. The vehicle should be serviced
by an authorized dealer as soon as possible if this
occurs.
Electronic Stability Control (ESC) Active
Warning Light — If Equipped
This warning light will indicate when the
ESC system is Active. The ESC Indicator
Light in the instrument cluster will come
on when the ignition is placed in the ON/
RUN or ACC/ON/RUN position, and when ESC is
activated. It should go out with the engine running.
If the ESC Indicator Light comes on continuously
with the engine running, a malfunction has been
detected in the ESC system. If this warning light
remains on after several ignition cycles, and the
vehicle has been driven several miles (kilometers)
at speeds greater than 30 mph (48 km/h), see an
authorized dealer as soon as possible to have the
problem diagnosed and corrected.
The ESC OFF Indicator Light and the ESC Indi -
cator Light come on momentarily each time the
ignition is placed in the ON/RUN or ACC/ON/
RUN position.
The ESC system will make buzzing or clicking
sounds when it is active. This is normal; the
sounds will stop when ESC becomes inactive.
This light will come on when the vehicle is in an
ESC event.
Electronic Stability Control (ESC) OFF
Warning Light — If Equipped
This warning light indicates the ESC is off.
Each time the ignition is turned to ON/
RUN or ACC/ON/RUN, the ESC system
will be on, even if it was turned off previously.
LaneSense Warning Light — If Equipped
The LaneSense system provides the
driver with visual and steering torque
warnings when the vehicle starts to drift
out of its lane unintentionally without the
use of a turn signal.
When the LaneSense system senses a lane drift
situation, the LaneSense indicator changes
from solid green to solid yellow.
When the LaneSense system senses the lane
has been approached and is in a lane departure
situation, the LaneSense indicator changes
from solid white/green to flashing yellow
Ú page 163.
Low Washer Fluid Warning Light —
If Equipped
This warning light will illuminate when the
windshield washer fluid is low
Úpage 350.
WARNING!
A malfunctioning catalytic converter can reach
higher temperatures than in normal operating
conditions. This can cause a fire if you drive
slowly or park over flammable substances such
as dry plants, wood, cardboard, etc. This could
result in death or serious injury to the driver,
occupants or others.
CAUTION!
Prolonged driving with the Malfunction Indicator
Light (MIL) on could cause damage to the
vehicle control system. It also could affect fuel
economy and driveability. If the MIL is flashing,
severe catalytic converter damage and power
loss will soon occur. Immediate service is
required.

23_DPF_OM_EN_USC_t.book Page 106

108GETTING TO KNOW YOUR INSTRUMENT PANEL
Anti-Lock Brake System (ABS) Warning
Light
This warning light monitors the ABS. The
light will turn on when the ignition is
placed in the ON/RUN or ACC/ON/RUN
position and may stay on for as long as
four seconds.
If the ABS light remains on or turns on while
driving, then the Anti-Lock portion of the brake
system is not functioning and service is required as
soon as possible. However, the conventional brake
system will continue to operate normally,
assuming the Brake Warning Light is not also on. If the ABS light does not turn on when the ignition
is placed in the ON/RUN or ACC/ON/RUN position,
have the brake system inspected by an authorized
dealer.
Service Forward Collision Warning (FCW)
Light — If Equipped
This warning light will illuminate to
indicate a fault in the Forward Collision
Warning System. Contact an authorized
dealer for service Ú
page 278.
Service LaneSense Warning Light —
If Equipped
This warning light will illuminate when the
LaneSense system is not operating and
requires service. Please see an
authorized dealer.
Service 4WD Warning Light — If Equipped
This warning light will illuminate to signal
a fault with the 4WD system. If the light
stays on or comes on during driving, it
means that the 4WD system is not
functioning properly and that service is required.
We recommend you drive to the nearest service
center and have the vehicle serviced immediately.
Cruise Control Fault Warning Light
This warning light will illuminate to
indicate the Cruise Control System is not
functioning properly and service is
required. Contact an authorized dealer.
YELLOW INDICATOR LIGHTS
Forward Collision Warning (FCW) Off
Indicator Light — If Equipped
This indicator light illuminates to indicate
that Forward Collision Warning is off
Ú page 277.
TOW/HAUL Indicator Light
This indicator light will illuminate when
TOW/HAUL mode is selected.
Trailer Merge Assist Indicator Light —
If Equipped
This indicator light will illuminate to
indicate when Trailer Merge Assist has
been activated.
Cargo Indicator Light — If Equipped
This indicator light will illuminate when
the cargo light is activated by pushing the
cargo light button on the headlight
switch.
CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures
and warning have been established for the tire
size equipped on your vehicle. Undesirable
system operation or sensor damage may result
when using replacement equipment that is not
of the same size, type, and/or style. Aftermarket
wheels can cause sensor damage. Using
aftermarket tire sealants may cause the Tire
Pressure Monitoring System (TPMS) sensor to
become inoperable. After using an aftermarket
tire sealant it is recommended that you take
your vehicle to an authorized dealer to have your
sensor function checked.

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GETTING TO KNOW YOUR INSTRUMENT PANEL111
BLUE INDICATOR LIGHTS
High Beam Indicator Light
This indicator light will illuminate to
indicate that the high beam headlights
are on. With the low beams activated,
push the multifunction lever forward
(toward the front of the vehicle) to turn on the high
beams. Pull the multifunction lever rearward
(toward the rear of the vehicle) to turn off the high
beams. If the high beams are off, pull the lever
toward you for a temporary high beam on, "flash to
pass" scenario.
ONBOARD DIAGNOSTIC SYSTEM — OBD II
Your vehicle is equipped with a sophisticated
Onboard Diagnostic system called OBD II. This
system monitors the performance of the
emissions, engine, and transmission control
systems. When these systems are operating
properly, your vehicle will provide excellent
performance and fuel economy, as well as engine
emissions well within current government
regulations. If any of these systems require service, the OBD II
system will turn on the Malfunction Indicator Light
(MIL). It will also store diagnostic codes and other
information to assist your service technician in
making repairs. Although your vehicle will usually
be drivable and not need towing, see an authorized
dealer for service as soon as possible.
ONBOARD DIAGNOSTIC SYSTEM
(OBD II) C
YBERSECURITY
Your vehicle is required to have an OBD II and a
connection port to allow access to information
related to the performance of your emissions
controls. Authorized service technicians may need
to access this information to assist with the
diagnosis and service of your vehicle and
emissions system Ú page 199.
CAUTION!
Prolonged driving with the MIL on could cause
further damage to the emission control
system. It could also affect fuel economy and
driveability. The vehicle must be serviced
before any emissions tests can be performed.
If the MIL is flashing while the vehicle is
running, severe catalytic converter damage
and power loss will soon occur. Immediate
service is required.
WARNING!
ONLY an authorized service technician should
connect equipment to the OBD II connection
port in order to read the VIN, diagnose, or
service your vehicle.
If unauthorized equipment is connected to the
OBD II connection port, such as a
driver-behavior tracking device, it may:
Be possible that vehicle systems,
including safety related systems, could be
impaired or a loss of vehicle control could
occur that may result in an accident
involving serious injury or death.
Access, or allow others to access, infor -
mation stored in your vehicle systems,
including personal information.
3

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112GETTING TO KNOW YOUR INSTRUMENT PANEL
EMISSIONS INSPECTION AND
MAINTENANCE PROGRAMS
In some localities, it may be a legal requirement to
pass an inspection of your vehicle's emissions
control system. Failure to pass could prevent
vehicle registration.
For states that require an Inspection and
Maintenance (I/M), this check verifies
the Malfunction Indicator Light (MIL) is
functioning and is not on when the
engine is running, and that the OBD II system is
ready for testing.
Normally, the OBD II system will be ready. The
OBD II system may not be ready if your vehicle was
recently serviced, recently had a depleted battery
or a battery replacement. If the OBD II system
should be determined not ready for the I/M test,
your vehicle may fail the test. Your vehicle has a simple ignition actuated test,
which you can use prior to going to the test station.
To check if your vehicle's OBD II system is ready,
you must do the following:

1. Cycle the ignition switch to the ON position,
but do not crank or start the engine.

NOTE:If you crank or start the engine, you will have to
start this test over.
2. As soon as you cycle the ignition switch to the ON position, you will see the Malfunction
Indicator Light (MIL) symbol come on as part of
a normal bulb check.
3. Approximately 15 seconds later, one of two things will happen:
The MIL will flash for about 10 seconds and
then return to being fully illuminated until
you turn OFF the ignition or start the engine.
This means that your vehicle's OBD II
system is not ready and you should not
proceed to the I/M station.
The MIL will not flash at all and will remain
fully illuminated until you place the ignition
in the off position or start the engine. This
means that your vehicle's OBD II system is
ready and you can proceed to the I/M
station.
If your OBD II system is not ready, you should see
an authorized dealer or repair facility. If your
vehicle was recently serviced or had a battery
failure or replacement, you may need to do nothing
more than drive your vehicle as you normally would
in order for your OBD II system to update. A
recheck with the previously mentioned test routine
may then indicate that the system is now ready.
Regardless of whether your vehicle's OBD II system
is ready or not, if the MIL is illuminated during
normal vehicle operation you should have your
vehicle serviced before going to the I/M station.
The I/M station can fail your vehicle because the
MIL is on with the engine running.

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STARTING AND OPERATING129
DIESEL EXHAUST BRAKE (ENGINE
BRAKING)
The purpose of the exhaust brake (engine braking)
feature is to supply negative (braking) torque from
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 sparing 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.
The exhaust brake feature will only function when
the driver toggles it on by pushing the exhaust
brake button until the Exhaust Brake Indicator is
illuminated. Normal (Full Strength) exhaust brake
mode is indicated by a yellow Exhaust Brake
Indicator.
Exhaust Brake Switch

Once the Exhaust Brake Indicator is illuminated
and the vehicle is moving faster than 5 mph
(8 km/h); 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 will downshift more
aggressively in TOW/HAUL mode when the exhaust
brake is enabled to increase brake performance.
WARNING!
Never use the PARK position as a substitute
for the parking brake. Always apply the
parking brake fully when parked to guard
against vehicle movement and possible injury
or damage.
Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Leaving unat -
tended children in a vehicle is dangerous for a
number of reasons. A child or others could be
seriously or fatally injured.
Do not leave the key fob in or near the vehicle,
or in a location accessible to children, and do
not leave a vehicle equipped with Keyless
Enter ‘n Go™ in the ACC or ON/RUN position.
A child could operate power windows, other
controls, or move the vehicle.
Be sure the parking brake is fully disengaged
before driving; failure to do so can lead to
brake failure and a collision.
Always fully apply the parking brake when
leaving your vehicle or it may roll and cause
damage or injury. Also, be certain to leave the
transmission in PARK. Failure to do so may
cause the vehicle to roll and cause damage or
injury.
CAUTION!
If the Brake System Warning Light remains on
with the parking brake released, a brake system
malfunction is indicated. Have the brake system
serviced by an authorized dealer immediately.
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 possibly resulting in
personal injury or death.
4

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STARTING AND OPERATING137
If the transmission temperature exceeds normal
operating limits, the powertrain controller will
modify the transmission shift schedule and expand
the range of torque converter clutch engagement.
This is done to prevent transmission 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 significant additional heat load on
the cooling system. Downshifting 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.
During cold temperatures, transmission operation
may be modified depending on engine and
transmission temperature as well as vehicle
speed. This feature improves warm-up time of the
engine and transmission to achieve maximum
efficiency. Engagement of the torque converter
clutch is inhibited until the transmission fluid is
warm Ú page 139. On trucks with AS66RC or AS69RC transmission,
FIFTH and SIXTH gears may be inhibited briefly on
cold starts below 41°F (5°C), and during very cold
temperatures (-4°F [-20°C] or below), operation
may briefly be limited to third gear only. During this
condition, the ability of the vehicle to accelerate
under heavily loaded conditions may be reduced.
In all cases, normal operation will resume once the
transmission temperature has risen to a suitable
level.
Transmission Limp Home Mode
Transmission function is monitored electronically
for abnormal 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 THIRD gear
regardless of which forward gear is selected. If an
AS66RC/AS69RC equipped truck enters
Transmission Limp Home Mode at highway
speeds, it will initially engage FIFTH gear, until the
vehicle slows to a speed where THIRD gear can be
engaged. PARK, REVERSE, and NEUTRAL will
continue to operate. The Malfunction Indicator
Light (MIL) may be illuminated. Transmission Limp
Home Mode allows the vehicle to be driven to an
authorized dealer for service without damaging the
transmission.
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 to the OFF position.
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
recommend that you visit an authorized dealer at
your earliest possible convenience. An authorized
dealer has diagnostic equipment to assess the
condition of your transmission.
If the transmission cannot be reset, authorized
dealer service is required.
Electronic Range Select (ERS) Operation
The ERS shift control allows the driver to limit the
highest available gear when the transmission is in
DRIVE. For example, if you set the transmission
gear limit to FOURTH gear, the transmission will
not shift above FOURTH gear, but will shift through
the lower gears normally.
4

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