TROUBLE SYMPTOM CHART


Prior to troubleshooting, check whether a malfunction is caused by external factor or vehicle conditions.

Ultrasonic misacceleration Mitigation System (UMS)


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.
    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.
Trouble symptom
 Inspection Procedure No.
 Reference page
Check the clearance warning control unit power supply circuit.
 1
The system cannot be switched on and off when the forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system ON/OFF switch is operated.
 2
The system cannot be activated or deactivated when you operate the sonar switch.
 3