2018 Ram 1500 Red light

— Air Suspension Ride Height Lowering
Indicator Light— If Equipped
This light will blink and alert the driver that the vehicle is
changing to a lower ride height.
— Air Suspension Entry/Exit Indicator Light— If
Equipped
This light comes on when the vehicle is automatically
lowered from ride height position downward for easy
entry and exit of the vehicle.
– 4WD Indicator Light — If Equipped
This light alerts the driver that the vehicle is in the
four-wheel drive mode, and the front and rear driveshafts
are mechanically locked together forcing the front and rear
wheels to rotate at the same speed.
— 4WD Low Indicator Light — If Equipped
This light alerts the driver that the vehicle is in the
four-wheel drive LOW mode. The front and rear drive-
shafts are mechanically locked together forcing the front
and rear wheels to rotate at the same speed. Low range
provides a greater gear reduction ratio to provide increased
torque at the wheels. Refer to “Four-Wheel Drive Operation — If Equipped” in
“Starting And Operating” for further information on four-
wheel drive operation and proper use.
Green Indicator Lights
— Park/Headlight On Indicator Light
This indicator will illuminate when the park lights or
headlights are turned on.
— Front Fog Indicator Light — If Equipped
This indicator will illuminate when the front fog lights are
on.
— Turn Signal Indicator Lights
When the left or right turn signal is activated, the turn
signal indicator will flash independently and the corre-
sponding exterior turn signal lamps will flash. Turn signals
can be activated when the multifunction lever is moved
down (left) or up (right).
NOTE:
•
A continuous chime will sound if the vehicle is driven
more than 1 mile (1.6 km) with either turn signal on.
• Check for an inoperative outside light bulb if either
indicator flashes at a rapid rate.
198 GETTING TO KNOW YOUR INSTRUMENT PANEL

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 prop-
erly, 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
your authorized dealer for service as soon as possible.
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.
(Continued)
CAUTION! (Continued)
•If the MIL is flashing while the vehicle is running,
severe catalytic converter damage and power loss
will soon occur. Immediate service is required.
Onboard Diagnostic System (OBD II) Cybersecurity
Your vehicle is required to have an Onboard Diagnostic
system (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 ac-
cess this information to assist with the diagnosis and
service of your vehicle and emissions system.
WARNING!
• ONLY an authorized service technician should con-
nect equipment to the OBD II connection port in
order to 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
(Continued)
200 GETTING TO KNOW YOUR INSTRUMENT PANEL

WARNING!(Continued)
vehicle control could occur that may result in an
accident involving serious injury or death.
• Access, or allow others to access, information
stored in your vehicle systems, including personal
information.
For further information, refer to “Cybersecurity” in “Mul-
timedia”.
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 Mainte-
nance (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 notbe ready if your vehicle was recently serviced, recently had a dead battery or a battery replace-
ment. 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 follow-
ing:
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 ten seconds and then return
to being fully illuminated until you turn OFF the igni-
tion or start the engine. This means that your vehicle’s
OBD II system is not readyand you should notproceed
to the I/M station.
4
GETTING TO KNOW YOUR INSTRUMENT PANEL 201

WARNING!(Continued)
•The capabilities of an ABS equipped vehicle must
never be exploited in a reckless or dangerous manner
that could jeopardize the user ’s safety or the safety of
others.
ABS is designed to function with the OEM tires. Modifica-
tion may result in degraded ABS performance.
Anti-Lock Brake Warning Light
The yellow “Anti-Lock Brake Warning Light” will turn on
when the ignition is turned to the ON/RUN mode and
may stay on for as long as four seconds.
If the “Anti-Lock Brake Warning Light” remains on or
comes on while driving, it indicates that the anti-lock
portion of the brake system is not functioning and that
service is required. However, the conventional brake sys-
tem will continue to operate normally if the “Brake System
Warning Light” is not on.
If the “Anti-Lock Brake Warning Light” is on, the brake
system should be serviced as soon as possible to restore the benefits of anti-lock brakes. If the “Anti-Lock Brake Warn-
ing Light” does not come on when the ignition is turned to
the ON/RUN mode, have the light repaired as soon as
possible.
Electronic Brake Control System
Your vehicle is equipped with an advanced Electronic
Brake Control system (EBC). This system includes Elec-
tronic Brake Force Distribution (EBD), Anti-Lock Brake
System (ABS), Brake Assist System (BAS), Hill Start Assist
(HSA), Traction Control System (TCS), Electronic Stability
Control (ESC), and Electronic Roll Mitigation (ERM). These
systems work together to enhance both vehicle stability
and control in various driving conditions.
Your vehicle may also be equipped with Trailer Sway
Control (TSC) and Hill Descent Control (HDC).
Electronic Brake Force Distribution (EBD)
This function manages the distribution of the braking
torque between the front and rear axles by limiting braking
pressure to the rear axle. This is done to prevent overslip of
the rear wheels to avoid vehicle instability, and to prevent
the rear axle from entering ABS before the front axle.
5
SAFETY 205

Brake System Warning Light
The red “Brake System Warning Light” will turn on when
the ignition is turned to the ON/RUN mode and may stay
on for as long as four seconds.
If the “Brake System Warning Light” remains on or comes
on while driving, it indicates that the brake system is not
functioning properly and that immediate service is re-
quired. If the “Brake System Warning Light” does not come
on when the ignition is turned to the ON/RUN mode, have
the light repaired as soon as possible.
Brake Assist System (BAS)
The BAS is designed to optimize the vehicle’s braking
capability during emergency braking maneuvers. The sys-
tem detects an emergency braking situation by sensing the
rate and amount of brake application and then applies
optimum pressure to the brakes. This can help reduce
braking distances. The BAS complements the anti-lock
brake system (ABS). Applying the brakes very quickly
results in the best BAS assistance. To receive the benefit of
the system, you must apply continuous braking pressure
during the stopping sequence, (do not “pump” the brakes).
Do not reduce brake pedal pressure unless braking is nolonger desired. Once the brake pedal is released, the BAS is
deactivated.
WARNING!
The Brake Assist System (BAS) cannot prevent the
natural laws of physics from acting on the vehicle, nor
can it increase the traction afforded by prevailing road
conditions. BAS cannot prevent collisions, including
those resulting from excessive speed in turns, driving
on very slippery surfaces, or hydroplaning. The capa-
bilities of a BAS-equipped vehicle must never be
exploited in a reckless or dangerous manner, which
could jeopardize the user’s safety or the safety of
others.
Hill Start Assist (HSA)
The HSA system is designed to mitigate roll back from a
complete stop while on an incline. If the driver releases the
brake while stopped on an incline, HSA will continue to
hold the brake pressure for a short period. If the driver
does not apply the throttle before this time expires, the
system will release brake pressure and the vehicle will roll
down the hill as normal.
206 SAFETY

The following conditions must be met in order for HSA to
activate:
•The feature must be enabled.
• The vehicle must be stopped.
• Park brake must be off.
• Driver door must be closed.
• The vehicle must be on a sufficient grade.
• The gear selection must match vehicle uphill direction
(i.e., vehicle facing uphill is in forward gear; vehicle
backing uphill is in REVERSE gear).
• HSA will work in REVERSE gear and all forward gears.
The system will not activate if the transmission is in
PARK or NEUTRAL. For vehicles equipped with a
manual transmission, if the clutch is pressed, HSA will
remain active.
WARNING!
There may be situations where the Hill Start Assist
(HSA) will not activate and slight rolling may occur,
such as on minor hills or with a loaded vehicle, or
(Continued)
WARNING! (Continued)
while pulling a trailer. HSA is not a substitute for
active driving involvement. It is always the driver ’s
responsibility to be attentive to distance to other ve-
hicles, people, and objects, and most importantly brake
operation to ensure safe operation of the vehicle under
all road conditions. Your complete attention is always
required while driving to maintain safe control of your
vehicle. Failure to follow these warnings can result in
a collision or serious personal injury.
Towing With HSA
HSA will also provide assistance to mitigate roll back while
towing a trailer.
WARNING!
•If you use a trailer brake controller with your trailer,
the trailer brakes may be activated and deactivated
with the brake switch. If so, there may not be enough
brake pressure to hold both the vehicle and the
trailer on a hill when the brake pedal is released. In
(Continued)
5
SAFETY 207

Traction Control System (TCS)
This system monitors the amount of wheel spin of each of
the driven wheels. If wheel spin is detected, the TCS may
apply brake pressure to the spinning wheel(s) and/or
reduce engine power to provide enhanced acceleration and
stability. A feature of the TCS, Brake Limited Differential
(BLD), functions similar to a limited slip differential and
controls the wheel spin across a driven axle. If one wheel
on a driven axle is spinning faster than the other, the
system will apply the brake of the spinning wheel. This
will allow more engine torque to be applied to the wheel
that is not spinning. BLD may remain enabled even if TCS
and ESC are in a reduced mode.
Electronic Stability Control (ESC)
This system enhances directional control and stability of
the vehicle under various driving conditions. ESC corrects
for oversteering or understeering of the vehicle by apply-
ing the brake of the appropriate wheel(s) to assist in
counteracting the oversteer or understeer condition. En-
gine power may also be reduced to help the vehicle
maintain the desired path.
ESC uses sensors in the vehicle to determine the vehicle
path intended by the driver and compares it to the actual
path of the vehicle. When the actual path does not matchthe intended path, ESC applies the brake of the appropriate
wheel to assist in counteracting the oversteer or understeer
condition.
•
Oversteer — when the vehicle is turning more than
appropriate for the steering wheel position.
• Understeer — when the vehicle is turning less than
appropriate for the steering wheel position.
The “ESC Activation/Malfunction Indicator Light” located
in the instrument cluster will start to flash as soon as the
ESC system becomes active. The “ESC Activation/
Malfunction Indicator Light” also flashes when the TCS is
active. If the “ESC Activation/Malfunction Indicator
Light” begins to flash during acceleration, ease up on the
accelerator and apply as little throttle as possible. Be sure to
adapt your speed and driving to the prevailing road
conditions.
WARNING!
• Electronic Stability Control (ESC) cannot prevent the
natural laws of physics from acting on the vehicle,
nor can it increase the traction afforded by prevailing
(Continued)
5
SAFETY 209

WARNING!(Continued)
road conditions. ESC cannot prevent accidents, in-
cluding those resulting from excessive speed in
turns, driving on very slippery surfaces, or hydro-
planing. ESC also cannot prevent accidents resulting
from loss of vehicle control due to inappropriate
driver input for the conditions. Only a safe, attentive,
and skillful driver can prevent accidents. The capa-
bilities of an ESC equipped vehicle must never be
exploited in a reckless or dangerous manner which
could jeopardize the user ’s safety or the safety of
others.
• Vehicle modifications, or failure to properly main-
tain your vehicle, may change the handling charac-
teristics of your vehicle, and may negatively affect
the performance of the ESC system. Changes to the
steering system, suspension, braking system, tire
type and size or wheel size may adversely affect ESC
performance. Improperly inflated and unevenly
worn tires may also degrade ESC performance. Any
vehicle modification or poor vehicle maintenance
that reduces the effectiveness of the ESC system can
increase the risk of loss of vehicle control, vehicle
rollover, personal injury and death.
ESC Operating Modes
NOTE: Depending upon model and mode of operation, the
ESC system may have multiple operating modes.
ESC On
This is the normal operating mode for the ESC. Whenever
the vehicle is started, the ESC system will be in this mode.
This mode should be used for most driving conditions.
Alternate ESC modes should only be used for specific
reasons as noted in the following paragraphs.
Partial Off
The “Partial Off” mode is intended for times when a more
spirited driving experience is desired. This mode may
modify TCS and ESC thresholds for activation, which
allows for more wheel spin than normally allowed. This
mode may be useful if the vehicle becomes stuck.
To enter the “Partial Off” mode, momentarily push the
“ESC Off” switch and the “ESC Off Indicator Light” will
illuminate. To turn the ESC on again, momentarily push
the “ESC Off” switch and the “ESC Off Indicator Light”
will turn off.
210 SAFETY