2018 Ram 2500 service

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 ve-
hicle will drive normally and will not require towing.
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 as soon as possible if this occurs.
WARNING!
A malfunctioning catalytic converter, as referenced
above, 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.
— Electronic Stability Control (ESC) Active
Warning Light — If Equipped
This light will indicate when the Electronic Stability Con-
trol 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 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
4
GETTING TO KNOW YOUR INSTRUMENT PANEL 193

CAUTION!(Continued)
Monitoring System (TPMS) sensor to become inoper-
able. After using an aftermarket tire sealant it is
recommended that you take your vehicle to your au-
thorized dealer to have your sensor function checked.
— Low Fuel Indicator Light
When the fuel level reaches approximately 3.0 gal (11.0 L)
this light will turn on, and remain on until fuel is added.
— Anti-Lock Brake (ABS) Warning Light
This light monitors the Anti-Lock Brake System (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 function-
ing 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.
— Low Coolant Level Warning Light
This telltale will turn on to indicate the vehicle coolant
level is low.
— Loose Fuel Filler Cap Warning Light — If
Equipped
This light will illuminate when the fuel filler cap is loose.
Properly close the filler cap to disengage the light. If the
light does not turn off, please see your authorized dealer.
— Service 4WD Warning Light — If Equipped
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.
Yellow Indicator Lights
— Transmission Temperature Warning Light
This light indicates that the transmission fluid temperature
is running hot. This may occur with severe usage, such as
trailer towing. If this light turns on, safely pull over and
stop the vehicle. Then, shift the transmission into PARK
and run the engine at idle or slightly higher until the light
turns off.
196 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

•The MIL will not flash at all and will remain fully
illuminated until you place the ignition in the off posi-
tion or start the engine. This means that your vehicle’s
OBD II system is readyand you can proceed to the I/M
station.
If your OBD II system is not ready,you should see your
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 above 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.
202 GETTING TO KNOW YOUR INSTRUMENT PANEL

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

Service TPMS Warning
If a system fault is detected, the “Tire Pressure Monitoring
Telltale Light” will flash on and off for 75 seconds and then
remain on solid. The system fault will also sound a chime.
In addition, the instrument cluster will display aSERVICE
TPM SYSTEM message for a minimum of five seconds and
then display dashes (- -) in place of the pressure value to
indicate which sensor is not being received.
If the ignition switch is cycled, this sequence will repeat,
providing the system fault still exists. If the system fault no
longer exists, the “Tire Pressure Monitoring Telltale Light”
will no longer flash, and the SERVICE TPM SYSTEMmessage will no longer display, and a pressure value will
display in place of the dashes. A system fault can occur due
to any of the following:
•
Signal interference due to electronic devices or driving
next to facilities emitting the same radio frequencies as
the TPM sensors.
• Installing aftermarket window tinting that contains ma-
terials that may block radio wave signals.
• Accumulation of snow or ice around the wheels or
wheel housings.
• Using tire chains on the vehicle.
• Using wheels/tires not equipped with TPM sensors.
A system fault may occur due to an incorrect TPM sensor
location condition. When a system fault occurs due to an
incorrect TPM sensor location, the “Tire Pressure Monitor-
ing Telltale Light” will flash on and off for 75 seconds and
then remain on solid. The system fault will also sound a
chime. In addition, the instrument cluster will display a
“Tire Pressure Temporarily Unavailable” message in place
of the tire pressure display screen. If the ignition switch is
cycled, this sequence will repeat, providing the system
fault still exists. If the system fault no longer exists, the
“Tire Pressure Monitoring Telltale Light” will no longer
Tire Pressure Monitor Display
220 SAFETY