PRE-CRASH SAFETY SYSTEM SYSTEM DESCRIPTION


  1. PRE-CRASH SAFETY SYSTEM DESCRIPTION


    1. The pre-crash safety system determines the possibility of a collision according to information such as the position of the obstacle and its relative speed, and provides optimal control to avoid a collision and control to reduce the impact during a collision via warnings, brake assist and automatic braking.

  2. FUNCTION OF COMPONENTS

    Component Function
    Pre-crash Safety City Sensor

    • Acquires information about a preceding vehicle from a monocular camera sensor and laser sensor to perform pre-crash safety system control.

    • Sends the information display, PCS OFF warning light and PCS warning message signal to the combination meter assembly based on pre-crash control information.

    • Sounds the PCS meter buzzer based on pre-crash safety system control information.*1

    • Sounds the pre-crash safety city buzzer based on pre-crash safety system control information.*2
    Pre-crash System Cancel Switch Assembly Turn the pre-crash safety system on/off and changes the warning timing.
    Pre-crash Safety City Buzzer*2 Sounds according to signals from the pre-crash safety city sensor.
    Combination Meter Assembly

    • Displays the pre-crash safety system status (ON/OFF) and warning timing.

    • During a system malfunction, warns the driver by displaying a message in the multi-information display according to the nature of the problem in the system, blinking the PCS OFF warning light and master warning light and sounding the meter buzzer.

    • Sounds the PCS meter buzzer according to signals from the pre-crash safety city sensor.*1
    ECM

    • Detects the shift position signal and accelerator pedal opening angle and sends that information to the pre-crash safety city sensor.*3

    • Detects the and accelerator pedal opening angle and sends that information to the pre-crash safety city sensor.*4

    • Performs engine output control based on information from the pre-crash safety city sensor.
    Brake Actuator Assembly (Skid Control ECU)

    • Sends information such as the vehicle speed signal, stop light switch signal and brake control hydraulic pressure to the pre-crash safety city sensor.

    • Performs brake hydraulic pressure and emergency brake signal control based on information from the pre-crash safety city sensor.
    Spiral Cable with Sensor Sub-assembly (Steering Sensor) Detects the steering angle and steering direction.
    Airbag Sensor Assembly (Yaw Rate and Acceleration Sensor) Detects the yaw rate and acceleration of the vehicle and transmits signals to the pre-crash safety city sensor.
    Main Body ECU (Multiplex network body ECU) Sends destination information to the pre-crash safety city sensor.
    VSC OFF Switch Disables the pre-crash brake and pre-crash brake assist operation when the switch is turned on.

    *1: w/o Pre-crash Safety City Buzzer

    *2: w/ Pre-crash Safety City Buzzer

    *3: for CVT, for Manual Transaxle with Pre-crash Safety City Heater

    *4: for Manual Transaxle without Pre-crash Safety City Heater

  3. OUTLINE OF PRE-CRASH DETECTION


    1. Collision detection


      1. The system determines in advance the possibility of a collision and whether the collision can be avoided based on road surface conditions and the position and speed of the preceding vehicle according to information about the preceding vehicle from the pre-crash safety city sensor.

        Tech Tips

        For details about the system, see "Outline of Pre-crash Safety System Control" and the function descriptions.

    2. Component

      Component Detection Content
      Pre-crash safety city sensor Obstacle in front (vehicle)

  4. OUTLINE OF PRE-CRASH SAFETY SYSTEM CONTROL

    Control Condition Start of Control Sender ECU Receiver ECU Operated Parts
    Pre-crash warning Collision is possible Pre-crash safety city sensor Combination meter assembly

    • Combination meter assembly (warning display)

    • PCS meter buzzer (warning sound)*1

    • Pre-crash safety city buzzer (warning sound)*2
    Pre-crash brake assist Collision is highly possible Pre-crash safety city sensor

    • Combination meter assembly

    • Brake actuator assembly (skid control ECU)

    • Combination meter assembly (warning display)

    • PCS meter buzzer (warning sound)*1

    • Pre-crash safety city buzzer (warning sound)*2

    • Brake actuator assembly (skid control ECU)
    Pre-crash brake Collision is unavoidable Pre-crash safety city sensor

    • Combination meter assembly

    • Brake actuator assembly (skid control ECU)

    • ECM

    • Combination meter assembly (warning display)

    • PCS meter buzzer (warning sound)*1

    • Pre-crash safety city buzzer (warning sound)*2

    • Brake actuator assembly (skid control ECU)

    *1: w/o Pre-crash Safety City Buzzer

    *2: w/ Pre-crash Safety City Buzzer

  5. PRE-CRASH ALARM CONTROL


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

  6. PRE-CRASH BRAKE ASSIST CONTROL


    1. When the system determines that the possibility of a frontal collision with a vehicle is high, the system applies greater braking force in relation to how strongly the brake pedal is depressed.

  7. PRE-CRASH BRAKE CONTROL


    1. When the system determines that the possibility of a frontal collision with a vehicle 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.

      Note

      When the system detects that the driver is attempting to cancel operation of the system by performing operations such as the following, pre-crash brake control will be canceled.


      • The accelerator pedal is depressed strongly.

      • Steering wheel is operated quickly to avoid a collision

    2. Turning the VSC OFF switch on disables pre-crash brake assist control and pre-crash brake control.

      Tech Tips

      After pressing the switch, the PCS OFF warning light in the combination meter assembly will illuminate and "Pre-Crash Brake is disabled due to VSC OFF." will be displayed in the multi-information display.

  8. PRE-CRASH SAFETY SYSTEM (PCS) OPERATION CONDITIONS


    1. The pre-crash alarm control, pre-crash brake assist control and pre-crash brake control can operate if all of the following conditions are met:


      • Pre-crash safety system is ON

      • VSC system is not disabled

      • PCS OFF warning light in the combination meter assembly is not blinking or illuminated

    2. If the following conditions are met, the pre-crash alarm control will operate:


      • Vehicle speed is between approximately 15 km/h (10 mph) and 140 km/h (87 mph)

      • Relative speed is approximately 15 km/h (10 mph) or more

    3. If the following conditions are met, the pre-crash brake assist control will operate:


      • Vehicle speed is between approximately 30 km/h (19 mph) and 80 km/h (50 mph)

      • Relative speed is approximately 30 km/h (19 mph) or more

    4. If the following conditions are met, the pre-crash brake control will operate:


      • Vehicle speed is between approximately 10 km/h (6 mph) and 80 km/h (50 mph)

      • Relative speed is approximately 10 km/h (6 mph) or more

  9. OUTLINE OF PRE-CRASH SAFETY CITY HEATER (w/ Pre-crash Safety City Heater)


    1. The pre-crash safety city heater can operate if all of the following conditions are met:


      • No pre-crash safety system DTCs are stored

      • Engine is running

    2. If either of the following conditions are met, the pre-crash safety city heater will operate:


      • Ambient temperature (detected by air conditioning system) is 5°C (41°F) or lower

      • Vehicle is being driven when ambient temperature is 5 to 20°C (41 to 68°F) and area of windshield in front of pre-crash safety city sensor begins to fog (blockage of pre-crash safety city sensor detected)

    3. If the following condition is met, the pre-crash safety city heater will stop operating:


      • 30 minutes have elapsed since pre-crash safety city heater operation began

  10. PRECAUTION FOR PRE-CRASH SAFETY CITY SENSOR


    1. When the following vehicle conditions are detected, the pre-crash safety city sensor may determine that the possibility of a collision is high or a collision is unavoidable and activate the pre-crash safety system, but this is not a malfunction.

      A002ZWCC01
      *A for RHD *B for LHD
      *a There are objects on the side of the road at the beginning of a curve (a guardrail, street light, billboard, etc.). *b Passing an oncoming vehicle on a curve.
      *c When passing an oncoming vehicle while making a left turn (for LHD) or right turn (for RHD). *d Passing through an area which contains an obstacle that covers the vehicle (such as a hanging curtain).
      *e There are metal objects, bumps or protrusions on the road (a metal plate covering road construction, a mesh drain cover, a manhole, etc.). *f Suddenly approaching a preceding vehicle.
      *g Approaching an electrical toll collection gate (reacts to bar). *h Crossing an overpass, traffic sign, signboard.
      *i The vehicle height drastically changes (nose-up, nose-down). *j Axis misalignment of pre-crash safety city sensor (reinstallation, applied impact, etc.).
      *k There is a billboard or sign at the top of an incline. *l There are metal objects at the bottom of a decline (a metal plate covering road construction, a mesh drain cover, a manhole, etc.).
      *m Snow, water, etc., is kicked up by a preceding vehicle. *n Passing through an area which contains heavy fog or smoke.
      *o Parking with the front of the vehicle extremely close to an obstacle (wall, vehicle, etc.). *p Passing extremely close to the side of an obstacle (stopped vehicle, guardrail, etc.).

    2. Situations in which the pre-crash safety system may not function properly.

      Figure 1. The system may not function properly in the following situations:

      A00301TC01
      *a The vehicle was being driven on roads with sharp bends or uneven surfaces. *b A vehicle suddenly crossed in front of the vehicle, such as at an intersection.
      *c A vehicle suddenly cut in front of the vehicle. *d The vehicle was skidding.
      *e The front part of the vehicle was raised or lowered. *f The windshield glass was dirty or covered with raindrops, condensation, ice, snow, etc.
      *g The sensor was misaligned due to a strong impact being applied to the sensor, etc. *h The preceding vehicle was a poor reflector of laser (the rear part of the vehicle was lowered, very dirty, etc.)
      *i A very bright light, such as the sun or headlights of oncoming traffic, was shining directly into the front sensor. *j The vehicle was being driven in inclement weather, such as heavy rain, fog, snow or a sandstorm.
      *k The vehicle was being driven in a dark area, such as a tunnel, or at night. - -

  11. PRE-CRASH SAFETY SYSTEM AUTOMATIC CANCELLATION


    1. When a system malfunction is detected and the pre-crash safety city sensor cannot detect vehicles, pre-crash safety system operation will be canceled automatically.

      Tech Tips

      If the pre-crash safety system is malfunctioning or temporarily disabled, the PCS OFF warning light will blink or illuminate.