Subaru Ascent 2018-2026 Owner's Manual: System operation

Operating conditions

The BSD/RCTA system in the Subaru Ascent functions only when specific operating requirements are satisfied. These conditions ensure accurate detection and reliable system performance.

• The ignition switch of the Subaru Ascent is in the "ON" position.
• The BSD/RCTA warning indicator and BSD/RCTA OFF indicator are not illuminated.
• The Subaru Ascent is traveling at speeds above approximately 7 mph (12 km/h), except during reversing maneuvers.
• The select lever is placed in the "R" position when using the Rear Cross Traffic Alert (RCTA) feature.

The BSD/RCTA system in the Subaru Ascent will not activate under the following conditions.

• The BSD/RCTA OFF indicator is illuminated.
• The vehicle speed is below approximately 6 mph (10 km/h), even if the system appears active (excluding reversing situations).

NOTE

• In certain situations, the BSD/RCTA system in the Subaru Ascent may stop functioning and display a warning indicator.

  If the BSD/RCTA warning indicator appears, it is recommended to have the Subaru Ascent inspected by an authorized SUBARU dealer as soon as possible to ensure proper system functionality.

  • This may occur when a malfunction develops within the system, including issues with the BSD/RCTA approach indicator lights.
• Under the following conditions, the BSD/RCTA system may temporarily suspend operation (or operate intermittently), and the BSD/RCTA OFF indicator will be displayed.
  • If the radar sensors on the Subaru Ascent become misaligned due to impact or other factors, recalibration will be required by a SUBARU dealer.
  • When snow, ice, or debris accumulates around the rear bumper area where the radar sensors are located.
  • When the Subaru Ascent is driven for extended periods in environments lacking surrounding objects, such as deserts or wide open areas.
  • When excessive heat builds up around the radar sensors, for example during prolonged uphill driving in hot weather.
  • When the temperature near the radar sensors drops to extremely low levels.
  • When the vehicle battery voltage drops below normal operating levels.
  • When the electrical system experiences overvoltage conditions.

  Once these conditions are resolved, the BSD/RCTA system in the Subaru Ascent will typically resume normal operation and the BSD/RCTA OFF indicator will disappear. If the indicator remains visible for an extended period, a professional inspection is strongly recommended.

• The effectiveness of the Subaru Ascent radar sensors may be limited under certain physical or environmental conditions, which can reduce detection accuracy or prevent proper system operation.
  • If the rear bumper area near the sensors is damaged or deformed.
  • If mud, ice, or snow adheres to the sensor surfaces.
  • If stickers or foreign materials are applied to the sensor zones on the rear bumper.
  • During adverse weather conditions such as heavy rain, snow, or dense fog.
  • When driving on wet or reflective surfaces, including puddles or snow-covered roads.
• The radar system in the Subaru Ascent may not detect, or may have difficulty detecting, certain types of objects or vehicles.
  • Small motorcycles, bicycles, pedestrians, or stationary roadside objects.
  • Vehicles with shapes that reflect radar signals poorly, such as low-profile sports cars or empty trailers.
  • Vehicles present within the detection zone but not approaching the Subaru Ascent directly, as detection is based on relative movement.
  • Vehicles moving at significantly different speeds compared to your Subaru Ascent.
  • Vehicles traveling alongside your Subaru Ascent at nearly identical speeds for extended periods.
  • Oncoming vehicles moving toward the Subaru Ascent.
  • Vehicles located beyond the immediately adjacent lane.
  • Slower-moving vehicles that the Subaru Ascent is overtaking.
• On roads with unusually narrow lanes, the Subaru Ascent BSD/RCTA system may detect vehicles traveling in lanes beyond the adjacent lane, which could result in additional alerts.

The Subaru Ascent BSD/RCTA system is engineered to enhance driver awareness and safety, but its performance depends on proper operating conditions, sensor cleanliness, and environmental factors. Drivers should always combine system feedback with direct observation for maximum safety.