2021 HONDA RIDGELINE warning light

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uuHonda Sensing ®u Collision Mitigation Braking SystemTM (CMBSTM)
Driving
The system has three alert stages for a possible collision. However, depending on circumstances, the CMBSTM may not go through all of
the stages before initiating the last stage.
■Collision Alert Stages
Distance between vehicles
CMBSTM
The radar sensor detects a vehicleAudible & Visual WARNINGSSteering WheelBraking
Stage oneThere is a risk of a collision
with the vehicle ahead of
you.
When in Long, visual and
audible alerts come on at a
longer distance from a vehicle
ahead than in Normal setting,
and in Short, at a shorter
distance than in Normal.
If an oncoming
vehicle is detected,
rapid vibration is
provided.
—
Stage
twoThe risk of a collision has
increased, time to respond
is reduced.
Visual and audible alerts.
—Lightly
applied
Stage
three The CMBSTM determines
that a collision is
unavoidable.
—Forcefully
applied
Your Vehicle Vehicle
Ahead
Normal
Short
Long
Your
Vehicle Vehicle
Ahead
Your
VehicleVehicle
Ahead

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uuHonda Sensing ®u Adaptive Cruise Control (ACC)
Driving
The system may automatically shut off and the ACC indicator will come on under
certain conditions. Some examples of these conditions are listed below. Other
conditions may reduce some of the ACC functions.
2 Front Sensor Camera P. 465
2 Radar Sensor P. 467
■Environmental conditions
Driving in bad weather (r ain, fog, snow, etc.).
■Roadway conditions
Driving on a snowy or wet roadway (obscured lane marking, vehicle tracks, reflected
lights, road spra y, high contrast).
■Vehicle conditions
• The outside of the windshield is blocked by dirt, mud, leaves, wet snow, etc.
• An abnormal tire or wheel condition (wrong size, varied size or construction,
improperly inflated, co mpact spare tire, etc.).
• The camera temperature gets too high.
• The parking brake is applied.
• The front grille is dirty.
• The vehicle is tilted due to a heavy load or suspension modifications.
• Tire chains are installed.
• The vehicle is towing a trailer.
■ACC Conditions and Limitations1ACC Conditions and Limitations
If you need the radar sensor to be repaired, or
removed, or the front grille is strongly impacted, turn
off the system by pressing the MAIN button and take
your vehicle to a dealer.
Have your vehicle checked by a dealer if you find any
unusual behavior of the system (e.g., the warning
message appears too frequently).

uuHonda Sensing ®u Lane Keeping Assist System (LKAS)
452
Driving
Provides assistance to keep the vehicle in the center of the lane. When the vehicle
nears a white or yellow line, steering force of the electric power steering will become
stronger.
When the vehicle enters the warning area, the LKAS alerts you with slight steering
wheel vibration as well as a warning display.
■Lane Keep Support Function1 Lane Keeping Assist System (LKAS)
When it fails to detect lanes, the system will
temporarily be canceled. When a lane is detected, the
system will recover automatically.
■Lane Departure Warning Function
Warning Area
Warning Area

525
Maintenance
Battery
Checking the Battery
The condition of the battery is monitored by a
sensor located on the negative terminal of the
battery. If there is a problem with this sensor,
the multi-information display will display a
warning message. If this happens, have your
vehicle inspected by a dealer.
Check the battery termi nals for corrosion
monthly.
To access the battery terminals:
1. Remove the engine compartment cover.
2 Engine Compartment Cover P. 498
2.Remove the clips using a phillips-head scre wdriver, then remove the air intake
duct.
2 High Beam Headlights P. 508
If your vehicle’s battery is disconnected or goes dead:
•The audio system is disabled.
2 Audio System Theft Protection P. 208
•The clock resets.
2 Clock P. 116
1Battery
WARNING: Battery post, terminals,
and related accessories contain lead
and lead compounds.
Wash your hands after handling.
When you find corrosion, cl ean the battery terminals
by applying a baking powder and water solution.
Clean the terminals with a damp towel. Cloth/towel
dry the battery. Coat the terminals with grease to
help prevent future corrosion.
When replacing the battery, the replacement must be
of the same specifications.
Consult a dealer for more information.
3WARNING
The battery gives off explosive hydrogen
gas during normal operation.
A spark or flame can cause the battery to
explode with enough force to kill or
seriously hurt you.
When conducting any battery
maintenance, wear prot ective clothing and
a face shield, or have a skilled technician do
it.
Models without navigation system

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Handling the Unexpected
If a Tire Goes Flat
Changing a Flat Tire
If a tire goes flat while driving, grasp the steering wheel firmly, and brake gradually
to reduce speed. Then, stop in a safe plac e. Replace the flat tire with a compact
spare tire. Go to a dealer as soon as possib le to have the full-size tire repaired or
replaced.
1. Park the vehicle on a firm, level, non-slippery surface and apply the parking brake.
2. Put the transmission into
(P.
3. Turn on the hazard warning lights an d set the power mode to VEHICLE OFF.
1Changing a Flat Tire
Follow compact spare precautions:
Periodically check the tire pressure of the compact
spare. It should be set to the specified pressure.
Specified Pressure: 60 psi (420 kPa, 4.2 kgf/cm
2)
When driving with the compact spare tire, keep the
vehicle speed under 50 mph (80 km/h). Replace with
a full-size tire as soon as possible.
The compact spare tire and wheel in your vehicle are
specifically for this model. Do not use them with
another vehicle. Do not us e another type of compact
spare tire or wheel with your vehicle.
Do not mount tire chains on a compact spare tire.
If a chain-mounted front tire goes flat, remove one of
the full-size rear tires and replace it with the compact
spare tire. Remove the flat front tire and replace it
with the full-size tire that was removed from the rear.
Mount the tire chains on the front tire.
Do not use a puncture-repairi ng agent on a flat tire,
as it can damage the tire pressure sensor.

552
Handling the Unexpected
If the Battery Is Dead
Turn off the power to electric devices, such as audio and lights. Turn off the engine,
then open the hood. 1.Pull up on the engine cover, remove it from
the pins.
u Start on the passenger side and lift the
outermost edge of the cover.
u Move towards the driver side while
applying uniform upward pressure.
2. Connect the first jump er cable to your
vehicle’s battery + terminal.
3. Connect the other end of the first jumper
cable to the booster battery + terminal.
u Use a 12-volt booster battery only.
u When using an automotive battery
charger to boost your 12-volt battery,
select a lower charging voltage than
15-volt. Check the charger manual for
the proper setting.
4. Connect the second jumper cable to the
booster battery - terminal.
■Jump Starting Procedure1If the Battery Is Dead
Securely attach the jumper cables clips so that they
do not come off when the e ngine vibrates. Also be
careful not to tangle the ju mper cables or allow the
cable ends to touch each other while attaching or
detaching the jumper cables.
Battery performance degrades in cold conditions and
may prevent the engi ne from starting.
3WARNING
A battery can explode if you do not follow
the correct procedure, seriously injuring
anyone nearby.
Keep all sparks, open flames, and smoking
materials away from the battery.
Pins
Engine Cover
Booster Battery

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Handling the Unexpected
Overheating
How to Handle Overheating
Overheating symptoms are as follows:
•The temperature gauge needle is at the mark or the engine suddenly loses
power.
• The Engine Temperature Too Hot message appears on the multi-information
display.
• Steam or spray comes out of the engine compartment.
■First thing to do
1. Immediately park the vehicle in a safe place.
2. Turn off all accessories and turn on the hazard warning lights.
u No steam or spray present: Keep the engine running and open the hood.
u Steam or spray is present: Turn off the engine and wait until it subsides.
Then open the hood.
1 How to Handle Overheating
NOTICE
Continuing to drive with the temperature gauge
needle at the mark may damage the engine.
Continuing to drive with the Engine Temperature
Too Hot message on the multi- information display
may damage the engine.
3WARNING
Steam and spray from an overheated
engine can seri ously scald you.
Do not open the hood if steam is coming
out.
H
H

557
Handling the Unexpected
Indicator, Coming On/Blinking
If the Low Oil Pressure Indicator Comes On
■Reasons for the indicator to come on
Comes on when the engine oil pressure is low.
■What to do as soon as the indicator comes on
1. Immediately park the vehicle on level ground in a safe place.
2. If necessary, turn the hazard warning lights on.
■What to do after parking the vehicle
1. Stop the engine and let it sit for approximately three minutes.
2. Open the hood and check the oil level.
2 Oil Check P. 500
3.Start the engine and check th e low oil pressure indicator.
u The indicator goes off: Start driving again.
u The indicator does not go off within 10 seconds: Immediately stop
the engine and contact a dealer for repairs.
If the Charging System Indicator Comes On
■Reasons for the indicator to come on
Comes on when there is a prob lem with the charging system.
■What to do when the indicator comes on
Turn off the climate control system, rear defogger, and other electrical
systems, and immediately co ntact a dealer for repairs.
1If the Low Oil Pressure Indicator Comes On
NOTICE
Running the engine with low oil pressure can cause
serious mechanical damage almost immediately.
1If the Charging System Indicator Comes On
If you need to stop temporarily, do not turn off the
engine. Restarting the engi ne may rapidly discharge
the battery.