2020 Ram 1500 ac low pressure switch

GETTING TO KNOW YOUR INSTRUMENT PANEL 185
— Electronic Stability Control (ESC) Off Warning
Light — If Equipped
This warning light indicates the Electronic Stability Control
(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 Lane -
Sense indicator changes from solid white/green to
flashing yellow.
• Refer to “LaneSense – If Equipped” in “Starting And Oper -
ating” for further information. — 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.
— Low Washer Fluid Warning Light — If Equipped
This warning light will illuminate when the windshield
washer fluid is low.
— Low Fuel Warning Light
When the fuel level reaches approximately 1.5 gal (5.5 L) this
light will turn on, and remain on until fuel is added.
A single warning chime will sound with Low Fuel Warning.
— Tire Pressure Monitoring System (TPMS) Warning
Light
The warning light switches on and a message is displayed to
indicate that the tire pressure is lower than the recom -
mended value and/or that slow pressure loss is occurring. In
these cases, optimal tire duration and fuel consumption may
not be guaranteed.
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SAFETY 207
Disabling HDC
HDC will be deactivated and disabled if any of the following
conditions occur:
• The driver pushes the HDC switch.
• The driveline is shifted out of the 4L Range.
• The park brake is applied.
• The driver door opens.
• The vehicle is driven greater than 20 mph (32 km/h) forgreater than 70 seconds.
• The vehicle is driven greater than 40 mph (64 km/h) (HDC exits immediately).
• HDC detects excessive brake temperature.
Feedback To The Driver
The instrument cluster has an HDC icon and the HDC switch
has an LED icon, which offers feedback to the driver about
the state HDC is in.
• The cluster icon and switch lamp will illuminate and remain on solid when HDC is enabled or activated. This is
the normal operating condition for HDC.
• The cluster icon and switch lamp will flash for several seconds, then extinguish when the driver pushes the HDC
switch but enable conditions are not met. • The cluster icon and switch lamp will flash for several
seconds, then extinguish when HDC disables due to excess
speed.
• The cluster icon and switch lamp will flash when HDC deactivates due to overheated brakes. The flashing will
stop and HDC will activate again once the brakes have
cooled sufficiently.
Hill Start Assist (HSA)
The Hill Start Assist (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.
WARNING!
HDC is only intended to assist the driver in controlling
vehicle speed when descending hills. The driver must
remain attentive to the driving conditions and is
responsible for maintaining a safe vehicle speed.4
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SAFETY 209
Towing With HSA
Hill Start Assist (HSA) will also provide assistance to miti-
gate roll back while towing a trailer. Disabling And Enabling HSA
This feature can be turned on or turned off. To change the
current setting, proceed as follows:
• If disabling HSA using your instrument cluster display,
refer to “Instrument Cluster Display” in “Getting To Know
Your Instrument Panel” for further information.
• If disabling HSA using Uconnect Settings, refer to “Ucon -
nect Settings” in “Multimedia” for further information.
For vehicles not equipped with an instrument cluster
display, perform the following steps:
1. Center the steering wheel (front wheels pointing straight forward).
2. Shift the transmission into PARK (P).
3. Apply the park brake.
4. Start the engine.
5. Rotate the steering wheel slightly more than one-half turn to the left.
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 order to avoid
rolling down an incline while resuming acceleration,
manually activate the trailer brake or apply more
vehicle brake pressure prior to releasing the brake
pedal.
• HSA is not a parking brake. Always apply the parking brake fully when exiting your vehicle. Also, be certain
to place the transmission in PARK.
• Failure to follow these warnings can result in a colli -
sion or serious personal injury.
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210 SAFETY

6. Push the “ESC Off” button located in the lower switch bankbelow the climate control four times within 20 seconds. The
“ESC Off Indicator Light” should turn on and turn off two
times.

7. Rotate the steering wheel back to center and then an addi -
tional slightly more than one-half turn to the right.
8. Turn the ignition to the OFF mode and then back to ON. If the sequence was completed properly, the “ESC Off
Indicator Light” will blink several times to confirm HSA
is disabled.
9. Repeat these steps if you want to return this feature to its previous setting.
Traction Control System (TCS)
The Traction Control System (TCS) 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.
Trailer Sway Control (TSC)
Trailer Sway Control (TSC) uses sensors in the vehicle to
recognize an excessively swaying trailer and will take the
appropriate actions to attempt to stop the sway. TSC will
become active automatically once an excessively swaying
trailer is recognized.
NOTE:
TSC cannot stop all trailers from swaying. Always use
caution when towing a trailer and follow the trailer tongue
weight recommendations. Refer to “Trailer Towing” in
“Starting And Operating” for further information.
When TSC is functioning, the “ESC Activation/Malfunction
Indicator Light” will flash, the engine power may be reduced
and you may feel the brakes being applied to individual
wheels to attempt to stop the trailer from swaying. TSC is
disabled when the ESC system is in the “Partial Off” or “Full
Off” modes.
WARNING!
If TSC activates while driving, slow the vehicle down,
stop at the nearest safe location, and adjust the trailer
load to eliminate trailer sway.
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SAFETY 231
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 System Warning
Light” will no longer flash, and the "SERVICE TPM
SYSTEM" message 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 drivingnext to facilities emitting the same radio frequencies as the
Tire Pressure Monitor (TPM) sensors
• Installing aftermarket window tinting that contains mate -
rials 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 loca -
tion condition. When a system fault occurs due to an incorrect
TPM sensor location, the “Tire Pressure Monitoring System
(TPMS) Warning 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 System Warning Light” will no longer flash and
the tire pressure display screen will be displayed showing the
tire pressure values the correct locations.

Vehicles With Non Matching Full Size Spare Or Compact
Spare
• The non matching full size spare or compact spare tire
does not have a TPM sensor. Therefore, the TPMS will not
monitor the pressure in the non matching full size spare or
compact spare tire.
• If you install the non matching full size spare or compact spare tire in place of a road tire that has a pressure below
the low-pressure warning limit, upon the next ignition
switch cycle, the Tire Pressure Monitoring System (TPMS)
Warning Light and a “LOW TIRE” message will remain
ON and a chime will sound. In addition, the graphic in the
instrument cluster will still display a pressure value in a
different color and an “Inflate to XX” message.
• After driving the vehicle for up to 20 minutes above 15 mph (24 km/h), the Tire Pressure Monitoring System
(TPMS) Warning Light will flash on and off for 75 seconds
and then remain on solid. In addition, the instrument
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232 SAFETY
cluster will display a "SERVICE TPM SYSTEM" message
for a minimum of five seconds and then display dashes (--)
in place of the pressure value.
• For each subsequent ignition switch cycle, a chime will sound, the Tire Pressure Monitoring System (TPMS)
Warning Light will flash on and off for 75 seconds and
then remain on solid, and the instrument cluster will
display a "SERVICE TPM SYSTEM" message for a
minimum of five seconds and then display dashes (--) in
place of the pressure value.
• Once you repair or replace the original road tire and rein -
stall it on the vehicle in place of the non matching full size
spare or compact spare, the TPMS will update automati -
cally. In addition, the Tire Pressure Monitoring System
(TPMS) Warning Light will turn OFF and the graphic in
the instrument cluster will display a new pressure value
instead of dashes (--), as long as no tire pressure is below
the low-pressure warning limit in any of the four active
road tires. The vehicle may need to be driven for up to
20 minutes above 15 mph (24 km/h) in order for the TPMS
to receive this information. Tire Fill Alert
This feature notifies the user when the placard tire pressure
is attained while inflating or deflating the tire.
The customer may choose to disable or enable the Tire Fill
Alert feature through use of the customer settings in the
radio.
NOTE:
• Only one tire can be filled at a time when using the Tire Fill
Alert system.
• The Tire Fill Alert feature cannot be entered if an existing TPM system fault is set to “active” or if the system is in
deactivation mode (if equipped).
The system will be activated when a positive increase in tire
pressure is detected by the TPM system while inflating the
tire. The ignition must be in the RUN mode, with the trans -
mission in PARK (P).
NOTE:
It is not required to have the engine running to enter Tire Fill
Alert mode.
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300 STARTING AND OPERATING
If exceptional circumstances should make it necessary to
engage the park brake while the vehicle is in motion, main-
tain upward pressure on the electric park brake switch for as
long as engagement is desired. The BRAKE telltale light will
illuminate, and a continuous chime will sound. The rear stop
lamps will also be illuminated automatically while the
vehicle remains in motion.
To disengage the park brake while the vehicle is in motion,
release the switch. If the vehicle is brought to a complete stop
using the parking brake, when the vehicle reaches approxi -
mately 3 mph, (5 km/h) the parking brake will remain
engaged.
• When exiting the vehicle, always remove the key fob
from the ignition and lock your vehicle.
• Never leave children alone in a vehicle, or with access to an unlocked vehicle. Allowing children to be in a
vehicle unattended is dangerous for a number of
reasons. A child or others could be seriously or fatally
injured. Children should be warned not to touch the
parking brake, brake pedal or the gear selector.
• Do not leave the key fob in or near the vehicle, or in a location accessible to children, and do not leave the
ignition of a vehicle equipped with Keyless
Enter-N-Go in the ACC or ON/RUN mode. 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 allow the vehicle to roll and cause
damage or injury.
WARNING! (Continued)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!
Driving the vehicle with the parking brake engaged, or
repeated use of the parking brake to slow the vehicle
may cause serious damage to the brake system. Be sure
the parking brake is fully disengaged before driving;
failure to do so can lead to brake failure and a collision.
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IN CASE OF EMERGENCY 477
NOTE:
When the lever is locked in the released position the access
cover cannot be reinstalled.
4. Behind the Manual Park Release access cover is theorange tether strap. Pull the tether strap out as far as it
will go, then release it. The tether and lever will remain
outside of the trim panel and the transmission should
now be in NEUTRAL, allowing the vehicle to be moved.
To Reset The Manual Park Release:
1. Apply firm pressure to the brake pedal while seated in the driver’s seat.
2. Pull the tether strap out again, then release it.
3. Allow the tether to retract with the lever back to its orig -
inal position.
4. Verify the transmission is in PARK.
5. Confirm that the tether has retracted fully and re-install the access cover. If the access cover cannot be reinstalled,
repeat steps 1 though 4.
6. Re-install the access cover.FREEING A STUCK VEHICLE
If your vehicle becomes stuck in mud, sand, or snow, it can
often be moved using a rocking motion. Turn the steering
wheel right and left to clear the area around the front wheels.
Then shift back and forth between DRIVE (D) and REVERSE
(R), while gently pressing the accelerator. Use the least
amount of accelerator pedal pressure that will maintain the
rocking motion, without spinning the wheels or racing the
engine.
NOTE:
Shifts between DRIVE and REVERSE can only be achieved at
wheel speeds of 5 mph (8 km/h) or less. Whenever the trans -
mission remains in NEUTRAL (N) for more than two
seconds, you must press the brake pedal to engage DRIVE or
REVERSE.
NOTE:
Push the “ESC Off” switch, to place the Electronic Stability
Control (ESC) system in “Partial Off” mode, before rocking
the vehicle. Refer to “Electronic Brake Control” in “Safety”
for further information. Once the vehicle has been freed,
push the “ESC Off” switch again to restore “ESC On” mode.
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