Lexus ES: PCS (Pre-Collision System)

The pre-collision system uses a radar sensor and front camera to detect objects in front of the vehicle. When the system determines that the possibility of a frontal collision with an object is high, a warning operates to urge the driver to take evasive action and the potential brake pressure is increased to help the driver avoid the collision. If the system determines that the possibility of a frontal collision with an object is extremely high, the brakes are automatically applied to help avoid the collision or help reduce the impact of the collision.

The pre-collision system can be disabled/ enabled and the warning timing can be changed.

Detectable objects

The system can detect the following:

• Vehicles
• Bicyclists
• Pedestrians

System functions

■ Pre-collision warning When the system determines that the possibility of a frontal collision is high, a buzzer will sound and a warning message will be displayed on the multi-information display to urge the driver to take evasive action.

■ Pre-collision brake assist When the system determines that the possibility of a frontal collision is high, the system applies greater braking force in relation to how strongly the brake pedal is depressed.

■ Pre-collision braking If the system determines that the possibility of a frontal collision is extremely high, the brakes are automatically applied to help avoid the collision or reduce the impact of the collision.

WARNING

■Limitations of the pre-collision system

• The driver is solely responsible for safe driving. Always drive safely, taking care to observe your surroundings.

  Do not use the pre-collision system instead of normal braking operations under any circumstances. This system will not prevent collisions or lessen collision damage or injury in every situation.

  Do not overly rely on this system.

  Failure to do so may lead to an accident, resulting in death or serious injury.

• Although this system is designed to help avoid a collision or help reduce the impact of the collision, its effectiveness may change according to various conditions, therefore the system may not always be able to achieve the same level of performance.

  Read the following conditions carefully.

  Do not overly rely on this system and always drive carefully.

  • Conditions under which the system may operate even if there is no possibility of a collision
  • Conditions under which the system may not operate properly
• Do not attempt to test the operation of the pre-collision system yourself.

  Depending on the objects used for testing (dummies, cardboard objects imitating detectable objects, etc.), the system may not operate properly, possibly leading to an accident.

■Pre-collision braking

• When the pre-collision braking function is operating, a large amount of braking force will be applied.
• If the vehicle is stopped by the operation of the pre-collision braking function, the pre-collision braking function operation will be canceled after approximately 2 seconds.

  Depress the brake pedal as necessary.

• The pre-collision braking function may not operate if certain operations are performed by the driver. If the accelerator pedal is being depressed strongly or the steering wheel is being turned, the system may determine that the driver is taking evasive action and possibly prevent the pre-collision braking function from operating.
• In some situations, while the pre-collision braking function is operating, operation of the function may be canceled if the accelerator pedal is depressed strongly or the steering wheel is turned and the system determines that the driver is taking evasive action.
• If the brake pedal is being depressed, the system may determine that the driver is taking evasive action and possibly delay the operation timing of the pre-collision braking function.

■When to disable the pre-collision system In the following situations, disable the system, as it may not operate properly, possibly leading to an accident resulting in death or serious injury:

• When the vehicle is being towed
• When your vehicle is towing another vehicle
• When transporting the vehicle via truck, boat, train or similar means of transportation
• When the vehicle is raised on a lift with the hybrid system on and the tires are allowed to rotate freely
• When inspecting the vehicle using a drum tester such as a chassis dynamometer or speedometer tester, or when using an on vehicle wheel balancer
• When a strong impact is applied to the front bumper or front grille, due to an accident or other reasons
• If the vehicle cannot be driven in a stable manner, such as when the vehicle has been in an accident or is malfunctioning
• When the vehicle is driven in a sporty manner or off-road
• When the tires are not properly inflated
• When the tires are very worn
• When tires of a size other than specified are installed
• When tire chains are installed
• When a compact spare tire or an emergency tire puncture repair kit is used
• If equipment (snow plow, etc.) that may obstruct the radar sensor or front camera is temporarily installed to the vehicle

Changing settings of the pre-collision system

■ Enabling/disabling the pre-collision system The pre-collision system can be enabled/disabled on of the multi-information display.

The system is automatically enabled each time the power switch is turned to ON mode.

If the system is disabled, the PCS warning light will turn on and a message will be displayed on the multi-information display.

■ Changing the pre-collision warning timing The pre-collision warning timing can be changed on of the multi-information display.

The warning timing setting is retained when the power switch is turned off. However, if the pre-collision system is disabled and re-enabled, the operation timing will return to the default setting (middle).

1. Early
2. Middle
   This is the default setting.
3. Late

■Operational conditions The pre-collision system is enabled and the system determines that the possibility of a frontal collision with a detected object is high.

Each function is operational at the following speed

• Pre-collision warning

• Pre-collision brake assist

• Pre-collision braking

The system may not operate in the following situations:

• If a 12-volt battery terminal has been disconnected and reconnected and then the vehicle has not been driven for a certain amount of time
• If the shift lever is in R
• When the VSC OFF indicator is illuminated (only the pre-collision warning function will be operational)

■Object detection function The system detects objects based on their size, profile, motion, etc. However, an object may not be detected depending on the surrounding brightness and the motion, posture, and angle of the detected object, preventing the system from operating properly.

The illustration shows an image of detectable objects.

■Cancelation of the pre-collision braking If either of the following occur while the pre-collision braking function is operating, it will be canceled:

• The accelerator pedal is depressed strongly.
• The steering wheel is turned sharply or abruptly.

■Conditions under which the system may operate even if there is no possibility of a collision

• In some situations such as the following, the system may determine that there is a possibility of a frontal collision and operate.

• When passing a detectable object, etc.
• When changing lanes while overtaking a detectable object, etc.
• When approaching a detectable object in an adjacent lane or on the roadside, such as when changing the course of travel or driving on a winding road

• When rapidly closing on a detectable object, etc.
• When approaching objects on the roadside, such as detectable objects, guardrails, utility poles, trees, or walls
• When there is a detectable object or other object by the roadside at the entrance of a curve

• When there are patterns or paint in front of your vehicle that may be mistaken for a detectable object
• When the front of your vehicle is hit by water, snow, dust, etc.
• When overtaking a detectable object that is changing lanes or making a right/left turn

• When passing a detectable object in an oncoming lane that is stopped to make a right/left turn

• When a detectable object approaches very close and then stops before entering the path of your vehicle
• If the front of your vehicle is raised or lowered, such as when on an uneven or undulating road surface
• When driving on a road surrounded by a structure, such as in a tunnel or on an iron bridge
• When there is a metal object (manhole cover, steel plate, etc.), steps, or a protrusion in front of your vehicle
• When passing under an object (road sign, billboard, etc.)

• When approaching an electric toll gate barrier, parking area barrier, or other barrier that opens and closes
• When using an automatic car wash
• When driving through or under objects that may contact your vehicle, such as thick grass, tree branches, or a banner

• When driving through steam or smoke
• When driving near an object that reflects radio waves, such as a large truck or guardrail
• When driving near a TV tower, broadcasting station, electric power plant, or other location where strong radio waves or electrical noise may be present

■Situations in which the system may not operate properly

• In some situations such as the following, an object may not be detected by the radar sensor and front camera, preventing the system from operating properly:

• When a detectable object is approaching your vehicle
• When your vehicle or a detectable object is wobbling
• If a detectable object makes an abrupt maneuver (such as sudden swerving, acceleration or deceleration)
• When your vehicle approaches a detectable object rapidly
• When a detectable object is not directly in front of your vehicle

• When a detectable object is near a wall, fence, guardrail, manhole cover, vehicle, steel plate on the road, etc.
• When a detectable object is under a structure
• When part of a detectable object is hidden by an object, such as large baggage, an umbrella, or guardrail
• When multiple detectable objects are close together
• If the sun or other light is shining directly on a detectable object
• When a detectable object is a shade of white and looks extremely bright
• When a detectable object appears to be nearly the same color or brightness as its surroundings
• If a detectable object cuts or suddenly emerges in front of your vehicle
• When the front of your vehicle is hit by water, snow, dust, etc.
• When a very bright light ahead, such as the sun or the headlights of oncoming traffic, shines directly into the front camera
• When approaching the side or front of a vehicle ahead
• If a vehicle ahead is a motorcycle
• If a vehicle ahead is narrow, such as a personal mobility vehicle
• If a preceding vehicle has a small rear end, such as an unloaded truck
• If a preceding vehicle has a low rear end, such as a low bed trailer

• If a vehicle ahead has extremely high ground clearance

• If a vehicle ahead is carrying a load which protrudes past its rear bumper
• If a vehicle ahead is irregularly shaped, such as a tractor or side car
• If a vehicle ahead is a child sized bicycle, a bicycle that is carrying a large load, a bicycle ridden by more than one person, or a uniquely shaped bicycle (bicycle with a child seat, tandem bicycle, etc.)
• If a pedestrian/or the riding height of a bicyclist ahead is shorter than approximately 3.2 ft. (1 m) or taller than approximately 6.5 ft. (2 m)
• If a pedestrian/bicyclist is wearing oversized clothing (a rain coat, long skirt, etc.), making their silhouette obscure
• If a pedestrian is bending forward or squatting or bicyclist is bending forward
• If a pedestrian/bicyclist is moving fast
• If a pedestrian is pushing a stroller, wheelchair, bicycle or other vehicle
• When driving in inclement weather such as heavy rain, fog, snow or a sandstorm
• When driving through steam or smoke
• When the surrounding area is dim, such as at dawn or dusk, or while at night or in a tunnel, making a detectable object appear to be nearly the same color as its surroundings
• When driving in a place where the surrounding brightness changes suddenly, such as at the entrance or exit of a tunnel
• After the hybrid system has started the vehicle has not been driven for a certain amount of time
• While making a left/right turn and for a few seconds after making a left/right turn
• While driving on a curve and for a few seconds after driving on a curve
• If your vehicle is skidding
• If the front of the vehicle is raised or lowered

• If the wheels are misaligned
• If a wiper blade is blocking the front camera
• The vehicle is being driven at extremely high speeds.
• When driving on a hill
• If the radar sensor or front camera is misaligned

• In some situations such as the following, sufficient braking force may not be obtained, preventing the system from performing properly:

• If the braking functions cannot operate to their full extent, such as when the brake parts are extremely cold, extremely hot, or wet
• If the vehicle is not properly maintained (brakes or tires are excessively worn, improper tire inflation pressure, etc.)
• When the vehicle is being driven on a gravel road or other slippery surface

■If VSC is disabled

• If VSC is disabled, the pre-collision brake assist and pre-collision braking functions are also disabled.
• The PCS warning light will turn on and "VSC Turned OFF Pre-Collision Brake System Unavailable" will be displayed on the multi-information display.

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