PRE-CRASH SAFETY SYSTEM DESCRIPTION
The pre-crash safety system uses the pre-crash alarm control, pre-crash brake assist control and pre-crash brake control to help avoid a collision or reduce the impact if it determines that the possibility of a collision is high based on the position and relative speed of a preceding vehicle.
The operation of this system can be turned off and on using the setting screen of the multi-information display.
Tech Tips
When the pre-crash safety system is turned off, the PCS indicator light in the combination meter assembly will illuminate.
PRE-CRASH SAFETY SYSTEM SENSOR DESCRIPTION
The millimeter wave radar sensor assembly and forward recognition camera detect the position and relative speed of preceding vehicles. This information is sent to the driving support ECU assembly to determine if the possibility of a collision is high.
OUTLINE OF PRE-CRASH SAFETY SYSTEM
PRE-CRASH ALARM:
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-CRASH 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-CRASH BRAKE*:
*: Depending on the region in which the vehicle was sold, the pre-crash brake control function may not be available.
When the system determines that the possibility of a frontal collision is high, the system warns the driver. If the system determines that the possibility of a collision is extremely high, the brakes are automatically applied to help avoid the collision or reduce the collision speed.
Tech Tips
The vehicle may creep after the pre-crash brake function has operated, the driver should depress the brake pedal as necessary.
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-crash brake function from operating.
ADAPTIVE VARIABLE SUSPENSION CONTROL:
When the driving support ECU determines that the possibility of a frontal collision is high, the adaptive variable suspension system controls the damping force of the shock absorbers to enhance the response of the vehicle.
PRE-CRASH SAFETY SYSTEM CONTROL OPERATION
| Control | Operating Condition | Transmitting ECU | Receiving ECU | Part Operated |
|---|---|---|---|---|
| Pre-crash alarm | Possibility of a collision is high | Driving Support ECU Assembly | Combination Meter Assembly |
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| Pre-crash brake assist |
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Driving Support ECU Assembly |
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| Pre-crash brake | Possibility of a collision is high | Driving Support ECU Assembly |
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| Adaptive variable suspension control | Possibility of a collision is high | Driving Support ECU Assembly | Suspension Control ECU |
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PRE-CRASH SAFETY SYSTEM OPERATION CONDITIONS
CAUTION:
Always observe the legal speed limit when driving on public roads.
| Pre-crash Alarm | Pre-crash Brake Assist | Pre-crash Brake |
|---|---|---|
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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 and operate.
When passing a vehicle.
When changing lanes while overtaking a preceding vehicle.
When overtaking a preceding vehicle that is changing lanes.
When overtaking a preceding vehicle that is making a left/right turn.
When passing a vehicle in an oncoming lane that is stopped to make a right/left turn.
When driving on a road where relative location to vehicle ahead in an adjacent lane may change, such as on a winding road.
When rapidly closing on a vehicle ahead.
If the front of the vehicle is raised or lowered, such as when the road surface is uneven or undulating.
When approaching objects on the roadside, such as guardrails, utility poles, trees or walls.
When there is a vehicle or object by the roadside at the entrance of a curve.
When driving on a narrow path 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 on the road surface or roadside.
When passing through a place with a low structure above the road (low ceiling, traffic sign, etc.).
When passing under an object (billboard, etc.) at the top of an uphill road.
When rapidly closing on 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 the vehicle, such as thick grass, tree branches or a banner.
When the vehicle is hit by water, snow, dust, etc. from a vehicle ahead.
When driving through steam or smoke.
When there are patterns or paint on the road or a wall that may be mistaken for a vehicle.
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, a vehicle may not be detected by the millimeter wave radar sensor assembly and forward recognition camera, preventing the system from operating properly:
If an oncoming vehicle is approaching the vehicle.
If a vehicle ahead is a motorcycle or bicycle.
When approaching the side or front of a 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 is carrying a load which protrudes past its rear bumper.
If a vehicle ahead has extremely high ground clearance.
If a vehicle ahead is irregularly shaped, such as a tractor or side car.
If the sun or other light is shining directly on a vehicle ahead.
If a vehicle cuts in front of your vehicle or emerges from beside a vehicle.
If a vehicle ahead makes an abrupt maneuver (such as sudden swerving, acceleration or deceleration).
When suddenly cutting behind a preceding vehicle.
When a vehicle ahead is not directly in front of your vehicle.
When driving in inclement weather such as heavy rain, fog, snow or a sandstorm.
When the vehicle is hit by water, snow, dust, etc. from a vehicle ahead.
When driving through steam or smoke.
When driving in a place where the surrounding brightness changes suddenly, such as at the entrance or exit of a tunnel.
When a very bright light, such as the sun or the headlights of oncoming traffic, shines directly into the forward recognition camera.
When the surrounding area is dim, such as at dawn or dusk, or while at night or in a tunnel.
After the engine 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 the 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 forward recognition camera.
The vehicle is wobbling.
The vehicle is being driven at extremely high speeds.
When driving on a hill.
If the millimeter wave radar sensor assembly 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 the PCS warning light flashes or illuminates and a warning message is displayed on the multi-information display
Tech Tips
For details on the operation of the PCS warning light and displayed warning messages, refer to Diagnosis System.
The pre-crash safety system may be temporarily unavailable or there may be a malfunction in the system.
In the following situations, the warning light will turn off, the message will disappear and the system will become operational when normal operating conditions return:
When the millimeter wave radar sensor assembly or forward recognition camera or the area around either sensor is hot, such as in the sun.
When the millimeter wave radar sensor assembly or forward recognition camera or the area around either sensor is cold, such as in an extremely cold environment.
When the millimeter wave radar sensor assembly is dirty or covered with snow, etc.
When the part of the windshield glass in front of the forward recognition camera is fogged up or covered with condensation or ice.
If the forward recognition camera is obstructed, such as when the hood is open or a sticker is attached to the windshield glass near the forward recognition camera.
If VSC is disabled
If VSC is disabled, the pre-crash brake assist and pre-crash brake functions are also disabled.
The PCS warning light will turn on and "VSC Turned Off Pre-crash Brake System Unavailable" will be displayed on the multi-information display.
FUNCTION OF MAIN COMPONENTS
| COMPONENTS | FUNCTION |
|---|---|
| Driving Support ECU Assembly |
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| Millimeter Wave Radar Sensor Assembly |
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| Forward Recognition Camera | Captures images of the area in front of the vehicle and processes them to detect preceding vehicles and sends information to the driving support ECU assembly. |
| Airbag Sensor Assembly | Detects the yaw rate and acceleration of the vehicle and sends signals to the driving support ECU assembly. |
| Spiral With Sensor Cable Sub-assembly | Detects the steering angle and direction and sends signals to the driving support ECU assembly. |
| Stop Light Switch Assembly | Detects the depression of the brake pedal and sends signals to the master cylinder solenoid (skid control ECU). |
| Stop Light Control Relay | Detects the depression of the brake pedal and sends signals to the master cylinder solenoid (skid control ECU). |
| Pre-crash System Cancel Switch Assembly | Illuminates the stop lights based on the pre-crash brake control operation signal from the skid control ECU. |
| Master Cylinder Solenoid (Skid Control ECU) |
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| Combination Meter Assembly |
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| Skid Control Buzzer | Sounds to warn the driver when the pre-crash alarm control is operated. |
| Main Body ECU (Multiplex Network Body ECU) | Sends vehicle destination country information to the driving support ECU assembly. |