Toyota Sienna 2023: Owner's Manual Excerpt for Driving Support Systems

Toyota Safety Sense 2.0

The Toyota Safety Sense 2.0 is a suite of drive assist systems designed to enhance safety and driving comfort. It operates under the assumption that the driver will drive safely and aims to reduce the impact of potential collisions or assist the driver in normal driving conditions. However, due to limitations in recognition accuracy and control performance, drivers must remain attentive to their surroundings and responsible for safe driving.

The system includes the following driving assist systems:

• PCS (Pre-Collision System): Refer to page 270.
• LTA (Lane Tracing Assist): Refer to page 278.
• AHB (Automatic High Beam): Refer to page 253.
• RSA (Road Sign Assist): (if equipped) Refer to page 288.
• Dynamic radar cruise control with full-speed range: Refer to page 291.

Sensors

The drive assist systems rely on two types of sensors located behind the front grille and windshield: a radar sensor (A) and a front camera (B).

System Warnings and Precautions

Radar Sensor Precautions

To prevent malfunction and potential accidents:

• Keep the radar sensor and its cover clean at all times. Clean with a soft cloth to avoid damage.
• Do not attach accessories, stickers, or other items to the radar sensor or its surrounding area.
• Avoid subjecting the radar sensor or its surrounding area to strong impacts. If an impact occurs, have the vehicle inspected by a Toyota dealer.
• Do not disassemble, modify, or paint the radar sensor or its cover.
• Recalibration by a Toyota dealer is required if the radar sensor, front grille, or front bumper is removed, installed, replaced, or if the front bumper is replaced.

Front Camera Precautions

To prevent malfunction and potential accidents:

• Keep the windshield clean. Remove dirt, oily film, water droplets, or snow.
• If a glass coating agent is applied, use windshield wipers to clear water droplets from the camera's view.
• If the inside of the windshield where the camera is installed is dirty, contact a Toyota dealer.
• Do not attach objects (stickers, etc.) to the outer windshield in the area of the front camera.
• Use the windshield defogger for fog, condensation, or ice on the windshield in front of the camera.
• If windshield wipers do not clear water droplets, replace the wiper insert or blade.
• Do not attach window tint to the windshield.
• If the windshield is damaged or cracked, it must be replaced, and the front camera recalibrated by a Toyota dealer.
• Do not allow liquids to contact the front camera.
• Do not expose the camera to bright lights.
• Do not dirty or damage the front camera lens. When cleaning the inside of the windshield, avoid contact with the lens.
• Do not subject the front camera to strong impacts.
• Do not change the camera's installation position or direction, or remove it.
• Do not disassemble the front camera.
• Do not modify components around the camera (e.g., rearview mirror, ceiling).
• Ensure accessories on the hood, grille, or bumper do not obstruct the camera. Contact a Toyota dealer if unsure.
• Objects mounted on the roof (e.g., surfboards) must not obstruct the front camera.
• Do not modify headlights or other lights.

Warning Messages and Troubleshooting

If a warning message appears on the multi-information display and the LTA indicator illuminates orange, follow the troubleshooting procedure. Common messages include:

• "LTA Malfunction Visit Your Dealer": Indicates a potential system malfunction; have the vehicle inspected.
• "LTA Unavailable": System temporarily canceled due to a sensor malfunction (other than the front camera). Turn the system off, wait, then turn it back on.
• "LTA Unavailable at Current Speed": Function cannot be used because vehicle speed exceeds the operational range. Drive slower.

Customization: Function settings can be changed via the multi-information display (refer to page 547).

LTA (Lane Tracing Assist)

The LTA system assists the driver by warning if the vehicle may deviate from its lane or course and can provide slight steering input to help maintain the lane. When Dynamic Radar Cruise Control is active, LTA helps maintain the vehicle's lane position.

The system recognizes lane lines (white/yellow) and preceding vehicles using the front camera and radar.

Important Warnings Before Using LTA:

• Do not rely solely on LTA; it does not drive the vehicle automatically and requires driver attention.
• The driver is always responsible for safe driving, paying attention to surroundings, and operating the steering wheel.
• Take adequate breaks when fatigued. Failure to do so may lead to accidents.
• Turn off the LTA system using the LTA switch when not in use.

Situations Unsuitable for LTA System

Turn off LTA in the following situations to avoid accidents:

• Slippery road surfaces (rain, snow, ice).
• Snow-covered roads.
• Poor visibility of lane lines (rain, snow, fog, dust).
• Temporary or restricted lanes due to construction.
• Driving in construction zones.
• When a spare tire, tire chains, or similar equipment is used.
• When tires are excessively worn or underinflated.
• Towing a trailer or during emergency towing.

Conditions Where LTA May Not Operate Properly

Functions may not operate correctly, and the vehicle may depart from its lane in these situations. Always drive safely and be prepared to correct the vehicle's path manually.

• Lane changes by preceding vehicles.
• Swaying preceding vehicles.
• Preceding vehicles departing from their lane.
• Preceding vehicles driving close to lane lines.
• Driving around sharp curves.
• Objects or patterns mistaken for lane lines (guardrails, reflective poles).
• Roads where lanes diverge or merge.
• Road repair marks or white/yellow lines.
• Shadows on lane lines.
• Areas without white/yellow lines (tollgates, intersections).
• Cracked lane lines, "Botts' dots", or raised pavement markers.
• Lane lines obscured by sand or other debris.
• Wet road surfaces (rain, puddles).
• Yellow traffic lines (may be harder to recognize than white).
• Lane lines crossing curbs.
• Bright road surfaces (e.g., concrete).
• Unclear or non-straight road edges.
• Surfaces with reflected light.
• Areas with sudden brightness changes (tunnel entrances/exits).
• Oncoming headlights or sun entering the camera.
• Driving on slopes or tilted roads.
• Winding roads.
• Unpaved or rough roads.
• Excessively narrow or wide traffic lanes.
• Vehicle tilted due to heavy luggage or improper tire pressure.
• Extremely short distance to preceding vehicle.
• Bumpy roads or road seams.
• Driving in tunnels or at night with dim or misaligned headlights.
• Crosswinds or wind from nearby vehicles.
• Recent lane changes or intersection crossings.
• Use of different tire types, brands, or tread patterns.
• Tires of non-specified sizes.
• Use of snow tires.
• Driving at extremely high speeds.

LTA Functions

• Lane Departure Alert Function: Warns the driver (buzzer or steering wheel vibration) if the vehicle deviates from its lane. The warning stops when the driver corrects the path. If the system detects the driver is not holding the steering wheel, it will warn and temporarily cancel the function.
• Steering Assist Function: Provides slight steering input to keep the vehicle in its lane. It may cancel if the steering wheel is not operated or gripped firmly.
• Vehicle Sway Warning Function: Alerts the driver with a buzzer and message if the vehicle is swaying within its lane.
• Lane Centering Function: Linked with Dynamic Radar Cruise Control, it operates the steering wheel to keep the vehicle in the lane. It can also follow a preceding vehicle if lane lines are not visible.

Turning LTA System On/Off

Press the LTA switch to turn the system on or off. The LTA indicator will illuminate, and a message will appear on the multi-information display. System settings persist between drives.

Indications on Multi-Information Display

• A LTA Indicator: White = LTA operating; Green = Steering assist/lane centering operating; Flashing Orange = Lane departure alert operating.
• B Operation Display of Steering Wheel Operation Support: Shows steering assist or lane centering operation. Lane lines on both sides indicate lane centering; one side indicates steering assist. Flashing lane lines alert the driver that input is needed.
• C Follow-up Cruising Display: Indicates steering assist for lane centering is active, following a preceding vehicle. Driver must remain attentive.
• D Lane Departure Alert Function Display: Indicates the lane departure alert function is active.

Visual Indicators for Lane Recognition

• Inside of displayed lines is white: System recognizes lane lines or course. If the vehicle departs, the line on that side flashes orange.
• Inside of displayed lines is black: System cannot recognize lane lines or course, or the function is temporarily canceled.

Operation Conditions of Each Function

Specific conditions must be met for each function to operate. These include system activation, vehicle speed, lane line visibility, lane width, driver input (or lack thereof), and absence of system malfunctions.

Lane Departure Alert Function Conditions: LTA on, speed ≥ 32 mph (50 km/h) (or less if lane centering is active), recognizable lane lines, lane width ≥ 9.8 ft (3 m), turn signal off, no sharp curves, no malfunctions.

Steering Assist Function Conditions: All Lane Departure Alert conditions plus "Steering Assist" setting ON, no significant acceleration/deceleration, no strong steering input, other systems (ABS, VSC, TRAC, PCS) not operating, TRAC/VSC not off, no "Hands off steering wheel" warning.

Vehicle Sway Warning Function Conditions: "Sway Warning" setting ON, speed ≥ 32 mph (50 km/h), lane width ≥ 9.8 ft (3 m), no malfunctions.

Lane Centering Function Conditions: LTA on, "Steering Assist" and "Lane Center" settings ON, recognizes lane lines/preceding vehicle, Dynamic Radar Cruise Control active, lane width 10-13 ft (3-4 m), turn signal off, no sharp curves, no malfunctions, no significant acceleration/deceleration, no strong steering input, other systems not operating, TRAC/VSC not off, no "Hands off steering wheel" warning, vehicle in lane center, steering assist not operating.

Temporary Cancellation of Functions

Functions may temporarily cancel if operating conditions are not met but will automatically restore when conditions are met again. If lane centering is operating and conditions change, the steering wheel may vibrate, or a buzzer may sound. The "Steering wheel vibration" setting can change the notification method.

Steering Assist Function/Lane Centering Function Interaction

Driver may not feel the function operating depending on speed, lane conditions, etc. Driver's steering input can override the system's control. Do not attempt to test the steering assist function.

Lane Departure Alert Function Limitations

Warning buzzers may be hard to hear due to noise. Steering wheel vibrations may be less noticeable due to road conditions. The function may not operate if lane edges are unclear or not straight. Interaction with Blind Spot Monitoring (BSM) may affect system determination of collision danger.

Hands Off Steering Wheel Warning

A warning message and symbol appear if the system detects the driver is not holding the steering wheel. Always keep hands on the wheel. If hands remain off, a buzzer sounds, and the function cancels. This applies even if only small steering inputs are made. The buzzer duration increases with continued lack of input.

Vehicle Sway Warning Function

If the vehicle is swaying, a buzzer sounds, and a warning message urges the driver to rest. The warning may not operate depending on vehicle and road conditions. Warnings may occur earlier on curves than on straight roads.