GENERAL INFORMATION


An ultrasonic misacceleration mitigation system is available as an option. This system detects an obstacle around the vehicle by using eight sensors (four on the front bumper, four on the rear bumper). When the system determines that the driver depresses the accelerator pedal abnormally or a collision is imminent, it will suppress the engine output. A corner sensor function is also available as an option. Depending on an obstacle detection, the vehicle drive information and the distance to the obstacle, this function alerts the driver visually and aurally by using the multi-information display.
note
  • On the M.U.T.-III, the ultrasonic misacceleration mitigation system/corner sensor system is referred to as "CORNER SENSOR/SONAR".
  • Vehicles for Hong Kong are equipped with the corner sensor system function only.

Construction diagram






Components and functional description
Component
 No.
 Functional Description
Forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system ON/OFF switch
 1
 Informs the ETACS-ECU whether the forward collision mitigation system and ultrasonic misacceleration mitigation system are switched on or off.
Sonar switch
 2
 Informs the clearance warning control unit whether the corner sensor function is switched on or off.
Steering wheel sensor
 3
 Sends the steering wheel angle signal to the clearance warning control unit.
Selector lever assembly
 4
 Informs the CVT-ECU or A/T-ECU of the selector lever status.
Combination meter
 5
  • Displays a relevant information on the information display and activates the buzzer according to the request from the clearance warning control unit.
Engine-ECU
 6
  • Informs the clearance warning control unit of an accelerator pedal opening angle.
  • Suppresses the engine output according to the request by the clearance warning control unit.
Clearance warning control unit
 7
 Determines whether the ultrasonic misacceleration mitigation system and the corner sensor function should be activated according to the results (such as distance) from the sensors, and sends the control request signals to the engine-ECU, etc.
ASC-ECU
 8
  • Sends vehicle speed and ASC status signals to the clearance warning control unit.
  • Informs the clearance warning control unit of the forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system ON/OFF switch status.
Front corner clearance sensor
 9
 Is located at the corner of the front bumper, and sends an obstacle detection signal to the clearance warning control unit.
Forward distance warning sensor
 10
 Is located at the centre of the front bumper, and sends an obstacle detection signal to the clearance warning control unit.
Ambient temperature sensor
 11
 Informs the ETACS-ECU of an ambient temperature.
ETACS-ECU
 12
 Informs the clearance warning control unit of an ambient temperature.
CVT-ECU or A/T-ECU
 13
 Sends the selector lever status to the clearance warning control unit.
Diagnosis connector
 14
 Is connected to M.U.T.-III to read the diagnosis code and service data associated with the clearance warning control unit.
Rear corner clearance sensor
 15
 Is located at the corner of the rear bumper, and sends an obstacle detection signal to the clearance warning control unit.
Back distance warning sensor
 16
 Is located at the centre of the rear bumper, and sends an obstacle detection signal to the clearance warning control unit.
Forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system OFF indicator
 17
 Is displayed when the FCM and ultrasonic misacceleration mitigation system functions are switched off.
Ultrasonic misacceleration mitigation system indication
 18
  • Is displayed when the ultrasonic misacceleration mitigation system are triggered.
  • Is displayed when the clearance warning control unit sets a diagnosis code.
Corner sensor system indication
 19
  • Is displayed when the corner sensor function is activated.
  • Displayed when the clearance warning control unit detects a sensor noise (affected sensor is designated).
System block diagram

note Dashed lines indicate the CAN bus line.

Ultrasonic misacceleration Mitigation System function


caution
  • The ultrasonic misacceleration mitigation system does not operate in the following conditions:

    1. The ignition switch is other than ON.
    2. The ultrasonic misacceleration mitigation system is set to OFF by operating the Forward Collision Mitigation System (FCM) and Ultrasonic misacceleration Mitigation System (UMS) ON/OFF switch.
    3. The FCM and Ultrasonic misacceleration Mitigation System (UMS) OFF indicator lights up.
    4. The selector lever is set to the "P" (PARK) or "N" (NEUTRAL) position.
  • It sometimes happens that a motorcycle, bicycle or pedestrian are detected as obstacles, but these are not the object of the Ultrasonic misacceleration Mitigation System operation.
  • The Ultrasonic misacceleration Mitigation System may not operate in the following conditions.

    1. When there is an extremely change in the outside temperature.
    2. Under adverse weather conditions (rain, strong winds, snow, sand storms, etc.).
    3. When approaching an obstacle too closely.
    4. When a vehicle cuts in front or behind your vehicle very closely.
    5. When only a part of the obstacle is within the detection areas of the sensor.
    6. When the rain, snow, water or dirt adheres to the sensor.
    7. When the sensor is extremely hot or cold (while the vehicle is parked for a long period of time under a blazing sun or in cold weather).
    8. Immediately after the engine starting is activated.
    9. When driving on a road with many and successive curves, including when passing their entrances and outlets.
    10. When driving on a road with steep and alternating up and down slopes.
    11. When a road surface is surging, and there is unevenness or gravel.
    12. When the system judges driver’s steering or gear shifting actions as evasive actions to avoid collision.
    13. For a short period after the system judges the repeated depression of the accelerator pedal at a few seconds interval as a release operation.
    14. When the vehicle body is extremely inclined by carrying heavy loads or improper adjustment of the tyre pressure.
    15. When the driving is unstable due to an accident or trouble.
    16. The system receives ultrasonic noise from other source (the horns of other vehicles, motorcycle engines, brakes, radios, pouring rain, splashing water, snow traction device (tyre chains), etc.).
    17. When the obstacle is not horizontal to the ground or not perpendicular to the vehicle traveling direction.
    18. The sensors or surroundings have been wiped by hand, or stickers or accessories have been attached.
  • The ultrasonic misacceleration mitigation system operation can be cancelled when the system judges the handle operation as evasive actions or when the obstacle moves out of the detectable area of the sensor.
  • The ultrasonic misacceleration mitigation system may not operate because the sensor cannot detect the vehicle or obstacle as follows.

    1. Vehicle towing a trailer etc.
    2. A freight trailer that is not carrying a container.
    3. Vehicle that has a protruding load from the carrier.
    4. Obstacles in low positions.
    5. Vehicle that is extremely stained.
    6. Vehicle or obstacle that is covered with snow.
    7. A large mesh screen fence.
    8. The vehicle is the specific shape such as the carrier car.
    9. Obstacles that have irregular surface.
    10. Obstacles that have the shape of the pole such as the road marker or the streetlight.
    11. Obstacles that exist in the high position from the ground.
    12. Obstacles that are soft and absorb ultrasonic easily, such as spongy material or snow.
    13. Obstacles that are shaped with a sharp angle.
  • The ultrasonic misacceleration mitigation system may be triggered under the following situations.

    1. When the surrounding vehicle or oncoming vehicle drives blowing up the water, snow or sand on the road.
    2. When the rain, snow, water or dirt adheres to the sensor.
    3. When there are objects, steps or projections on the road surface.
    4. When the parking gate or railway barrier is raised imperfectly.
    5. When running the road, the gradient changes suddenly.
    6. When passing through the mass of the steam, fog.
    7. When passing close to the vehicle or an obstacle.
    8. When passing through a vinyl curtain etc.
    9. When the surrounding area is overgrown with weeds.
    10. When leaving from a parallel parking.
    11. The system receives ultrasonic noise from other sources (the horns of other vehicles, motorcycle engines, brakes, radios, pouring rain, splashing water, snow traction device (tyre chains), etc.).
  • Turn off the system by pressing the Forward Collision Mitigation System (FCM) and Ultrasonic misacceleration Mitigation System (UMS) ON/OFF switch beforehand when the vehicle is placed in any of the following situations as the system can operate unexpectedly.

    1. When using an automatic car wash.
    2. When returning the fallen wheel in a ditch or escaping from mud.
    3. When using a vehicle elevator or a Multi-storey car park.
    4. Do not modify the suspension of your vehicle.
    5. When your vehicle’s wheels are driven by the engine on a lift.
    6. When your vehicle is towed or your vehicle tows another vehicle.
    7. When your vehicle is carried on a truck.
    8. When enjoying sports driving on a circuit.
    9. When your vehicle is on a chassis dynamometer or free rollers.
    10. When the tyre pressure is not proper.
    11. When tyre chains are attached.

Operation


The ultrasonic misacceleration mitigation system function mitigates a collision injury by avoiding abrupt vehicle start and suppressing the electric motor output when the sensor detects another vehicle or an obstacle ahead or behind (within approximately 4 m or less) with your vehicle stationary or at low speed (approximately 10 km/h or less) and the steering wheel not turned extremely. When this system is triggered, an LCD display in the combination meter and a buzzer warns the driver visually and aurally.
note
  • When the towing bar mode is set by the corner sensor function, the area, which the sensor does not sense at the rear of the vehicle, is the same as for the activated corner sensor function. (Refer to "Corner sensor function operation")
  • If the UMS condition, which is related to an abnormal accelerator pedal operation, is satisfied three times within two seconds each, the third triggering will be rejected. Then the system will be disabled for 30 seconds.


Ultrasonic misacceleration mitigation system indication on the combination meter (multi-information display), forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system OFF indication on the combination meter (multi-information display), and a buzzer




When the system detects an obstacle in the running direction of the vehicle and recognises an abnormal accelerator pedal depression at vehicle start or low speed, it informs the driver that the ultrasonic misacceleration mitigation system function has been activated. This is achieved visually and aurally by using the multi-information display and the buzzer integrated in the clearance warning control unit. When the system detects an intermittent critical error temporarily due to an abnormal sensor signal, the system alerts the driver that the UMS is disabled temporarily. When the system detects an continuous critical error, the system alerts the driver that the UMS is disabled forcibly. When the system is switched off by using the forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system ON/OFF switch, this information is also displayed.
Status
 Ultrasonic misacceleration mitigation system indication
 Forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system OFF indication
 Buzzer
The UMS is activated but the sensors are not activated
 Not displayed
 Not displayed
 -
The UMS is deactivated by pressing the OFF switch.
 OFF display
 Display
 -
All of the UMS functions has been disabled forcibly as the system has detected a critical failure.
Forcible deactivation displayed
 Display*
 -
The system has disabled the UMS function temporarily as it has detected any critical failure (e.g. unfeasible sensor reception signal).
 Temporary deactivation displayed
 Display*
 -
The UMS and the sensors are activated
 Operation display
 Not displayed
 Sounds intermittently when "ACCELERATION PEDAL PRESSED" is shown on the combination meter.
note Not displayed when the FCM is off.

Corner sensor system function


Operation


The corner sensor system function measures the distance to the obstacle around your vehicle. Depending on the distance, the system warns the driver visually and aurally by using the display in the combination meter and the buzzer.


THE TOWING BAR MODE SWITCHING


By operating the sonar switch, "TOWING BAR MODE" and "STANDARD MODE" can be changed.

  1. Turn the ignition switch to the ON position.
  2. Move the shift lever or selector lever to the "R" (reverse) position.
  3. Turn off the corner sensor system by operating the sonar switch.(Corner sensor indicator: OFF)
  4. Press and hold the sonar switch for approximately 5 seconds.
  5. The buzzer* sounds and the mode is switched between "TOWING BAR MODE" and "STANDARD MODE".
note *: Sounds twice when the mode is switched to "TOWING BAR MODE". Sounds once when the mode is switched to "STANDARD MODE".

"Corner sensor" information on the combination meter (multi-information display)




When there is an obstacle at a corner of the vehicle, the direction to the obstacle is displayed by the corner sensor indicator on the multi-information display of the combination meter, and then the buzzer integrated in the clearance warning control unit sounds.

BACK DISTANCE WARNING SENSOR
Distance between back sensor and obstacles
 Indicator duration
The standard mode
 The towing bar mode
Less than approximately 40 cm

No warning
Approximately 40 to 60 cm



Approximately 60 to 80 cm



Approximately 80 to 100 cm
 -

Approximately 80 to 125 cm

-
Approximately 100 to 125 cm
 -


CORNER CLEARANCE SENSOR
Distance between corner sensor and obstacles
 Indicator duration
Less than approximately 30 cm

Approximately 30 to 40 cm

Approximately 40 to 60 cm


FORWARD DISTANCE WARNING SENSOR
Distance between corner sensor and obstacles
 Indicator duration
Less than approximately 40 cm

Approximately 40 to 50 cm

Approximately 50 to 60 cm


When a sensor fails
What is designated
 Indicator duration
Only a faulty sensor is designated as a symbol.

Patterns and duration of warning buzzer


The buzzer duration varies with the remaining distance between vehicle and obstacles.

BACK DISTANCE WARNING SENSOR
Distance between back sensor and obstacles
 Buzzer duration
The standard mode
 The towing bar mode
Less than approximately 40 cm

Buzzer: OFF
Approximately 40 to 60 cm



Approximately 60 to 80 cm



Approximately 80 to 100 cm



Approximately 100 to 120 cm



Approximately 120 to 125 cm




CORNER CLEARANCE SENSOR
Distance between corner sensor and obstacles
 Buzzer duration
Less than approximately 30 cm

Approximately 30 to 40 cm

Approximately 40 to 60 cm


FORWARD DISTANCE WARNING SENSOR
Distance between corner sensor and obstacles
 Buzzer duration
Less than approximately 40 cm

Approximately 40 to 50 cm

Approximately 50 to 60 cm


Abnormal
Buzzer duration


Clearance warning control unit


The clearance warning control unit calculates the distance to an obstacle by using ultrasonic sensors when the vehicle is driven forwards or rearwards (reversed). Then the control unit activates the ultrasonic misacceleration mitigation system indication, the corner sensor system indication on the multi-information display in the combination meter and the buzzer (incorporated in the clearance warning control unit).

Forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system ON/OFF switch




The forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system ON/OFF switch is located at the left side of the instrument panel lower. You can activate and deactivate the FCM and the UMS by operating this switch. To activate (or trigger) the UMS, you should activate (or trigger) the FCM.
note
  • When the ignition switch is switched on, the FCM and the UMS will be switched on automatically.
  • When the forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system ON/OFF switch is operated, the buzzer will sound.Note that it does not sound on vehicles with forward collision mitigation system (FCM).
Switching off the system
Switching on the system

Sonar switch




The sonar switch is located at the left side of the instrument panel lower. You can switch on and off the corner sensor function by operating this switch.

Fail-safe and diagnosis functions


The clearance warning control unit always monitors input and output signals. When the system detects any malfunction, it will display a relevant message on the combination meter to alert the driver and disable the UMS and corner sensor functions if necessary.
In addition, the clearance warning control unit has the following functions to facilitate system checks:

You can read the all items above by using the M.U.T.-III.

CODING FUNCTION


You can assign a proper vehicle information and specifications peculiar to your vehicle by using coding function (CAN).