Toyota bZ4X Owner's Manual: Hyundai Rear Cross Traffic Alert (RCTA) for Enhanced Backing Safety

The Rear Cross Traffic Alert (RCTA) function in your Hyundai utilizes the BSM rear side radar sensors, which are strategically installed behind the rear bumper. This innovative safety feature is designed to greatly assist the driver in checking those hard-to-see areas directly to the left and right when the vehicle is in reverse.

WARNING - Important Safety Information Regarding RCTA System Use

Driver Responsibility for Safe Operation

Remember, as the driver, you are always ultimately responsible for the safe operation of your vehicle. It is crucial to drive safely at all times, diligently observing your entire surroundings, especially when maneuvering in reverse.

Over-relying solely on the RCTA system without visually checking your surroundings can be dangerous and may lead to an accident, potentially causing serious injury or even death.

Conditions for Proper System Functionality

System components

1. Meter control switches

Operate the meter control switches to enable/disable the RCTA function on the multi-information display.

2. Outside rear view mirror indicators

If a vehicle is detected as approaching from the left or right behind the vehicle, both outside rear view mirror indicators  will blink and a buzzer will sound.

3. Multimedia display

If a vehicle approaching from the right or left at the rear of the vehicle is detected, the RCTA icon  for the detected side will be displayed on the multimedia display.

This illustration* shows an example of a vehicle approaching from both sides of the vehicle.

*: Depending on the vehicle grade and equipped options, the actual screen may be different from this illustration.

4. Driving assist information indicator

Illuminates when the RCTA is turned off. At this time, a message will be displayed on the multi-information display.

Turning the RCTA function On or Off in your 2025 Toyota bZ4X

The Rear Cross Traffic Alert system in the 2025 Toyota bZ4X can be conveniently enabled or disabled through the vehicle's customizable settings, often accessible via the central infotainment display.

When the RCTA function is turned off, the driving assist information indicator on the dashboard will illuminate, and a corresponding message will typically be displayed on the multi-information display to notify you that the system is inactive.

For your convenience and safety, each time the power switch of your 2025 Toyota bZ4X is turned to the ON position, the RCTA function is automatically enabled, ensuring it's ready to assist you during your driving sessions.

Outside Rear View Mirror Indicator Visibility

Please note that in conditions of strong, direct sunlight, the indicator light located in the outside rearview mirror that alerts you to cross-traffic might become less noticeable. Always supplement your reliance on the indicator with a thorough visual check.

Hearing the RCTA Buzzer

It's important to be aware that the audible alert from the RCTA system, the buzzer, might be difficult to hear if there is significant ambient noise, such as when the vehicle's audio system volume is set at a high level. Keep this in mind while backing up.

How the RCTA function works in your Toyota bZ4X

The Rear Cross Traffic Alert function in the 2025 Toyota bZ4X utilizes advanced rear side radar sensors. These sensors are designed to detect vehicles approaching from either the right or the left at the rear of your vehicle when you are backing up. Upon detecting an approaching vehicle, the system will alert the driver to their presence by rapidly flashing the indicators located on the outside rearview mirrors and simultaneously sounding an audible buzzer, providing both visual and auditory warnings.

Modern electric vehicles like the Toyota bZ4X increasingly feature sophisticated sensor-based safety systems like RCTA, which contribute significantly to overall driver awareness and collision avoidance.

1. Approaching vehicles
2. Detection areas of approaching vehicles

RCTA icon display

When a vehicle approaching from the right or left at the rear of the vehicle is detected, the following will be displayed on the multimedia display.

• Example (Panoramic view monitor): Vehicles are approaching from both sides of the vehicle

RCTA function detection areas

The areas that vehicles can be detected in are outlined below.

The buzzer can alert the driver of faster vehicles approaching from farther away.

Example: 

Conditions for RCTA Operation

The Rear Cross Traffic Alert (RCTA) system in your 2025 Toyota bZ4X is designed to be operational only when specific conditions are met to ensure its effectiveness and prevent unnecessary alerts. These conditions include:

• Power Switch is ON: The vehicle's main power must be turned on for any of its safety systems, including RCTA, to function.
• RCTA Function is On: The RCTA feature must be enabled within the vehicle's settings. As noted previously, it typically defaults to the 'on' state each time you start your Toyota bZ4X.
• Shift Position is in R (Reverse): The RCTA system is specifically designed to assist when you are backing up, so it will only engage when the vehicle is in reverse gear.
• Vehicle Speed is Low: The system is most effective at low speeds, typically when maneuvering in parking lots or driveways. It operates when your vehicle's speed is less than approximately 9 mph (15 km/h).
• Approaching Vehicle Speed is Within Range: The radar sensors are calibrated to detect vehicles moving at a certain speed relative to your own. The RCTA system is designed to alert you to vehicles approaching from the side at a speed between approximately 5 mph (8 km/h) and 34 mph (56 km/h). This range covers typical speeds of vehicles moving across your path in parking scenarios.

Adjusting the Buzzer Volume for RCTA and Parking Assistance in Your Toyota bZ4X

The volume of the audible alerts from the RCTA system, as well as the intuitive parking assist (if your 2025 Toyota bZ4X is equipped), and the Rear Camera Detection (RCD) system (if equipped), can all be conveniently adjusted together through the vehicle's customize settings menu, often found within the infotainment system's audio or safety options.

Temporarily Muting the RCTA and Parking Buzzer

When the parking assist or RCTA system detects an object while you are maneuvering your 2025 Toyota bZ4X, a temporary mute switch will often be displayed on the multimedia display screen.

By selecting this mute switch on the screen, you can temporarily silence the buzzer for the intuitive parking assist (if equipped), RCTA (if equipped), and RCD all at once, which can be useful in certain low-speed maneuvering situations.

The mute function will be automatically canceled under several circumstances to ensure the systems remain active when needed:

• When the shift position is changed from Reverse to Drive or Park, for example.
• When the vehicle speed exceeds a certain low threshold.
• If there is a malfunction detected in one of the sensors, or if the system becomes temporarily unavailable for any reason.
• If the operating function is manually disabled through the vehicle's settings.
• When the power switch of your Toyota bZ4X is turned off and then back on.

Limitations: When the RCTA System Might Not Detect a Vehicle

It's important to understand that the RCTA function on your 2025 Toyota bZ4X has limitations and is not designed to detect all types of vehicles and/or objects in every situation. Here are some examples:

• Vehicles approaching from directly behind your vehicle will not be detected as the sensors are primarily facing the sides.
• Vehicles that are also backing up within an adjacent parking space might not be detected reliably, as the system is optimized for detecting crossing traffic.
• Any vehicles or objects that are obstructed from the sensors' view by other obstacles might not be detected.

• Stationary objects such as guardrails, walls, signs, and parked vehicles are generally not intended targets for detection by the RCTA system*.
• Smaller objects like small motorcycles, bicycles, or pedestrians might present a challenge for detection depending on their size and speed*.
• Vehicles that are moving away from your vehicle will not trigger an alert.
• Vehicles approaching slowly from parking spaces immediately next to yours might not be detected until they are further into your intended path*.
• If the distance between the sensor on your vehicle and the approaching vehicle becomes extremely close, the system might not have enough time to provide an alert.

*: Please be aware that depending on specific environmental conditions and the characteristics of the vehicle or object, detection may still occur in some of these scenarios. Understanding these limitations is crucial for responsible use of the RCTA system.

The Rear Cross Traffic Alert (RCTA) function in your 2025 Toyota bZ4X relies on sensor data, and its effectiveness can be influenced by various external factors. Therefore, the system may not detect approaching vehicles correctly in the following situations:

• Sensor Misalignment: If the radar sensor has become misaligned due to a significant impact in the sensor area or the surrounding bumper, it may not function as intended.
• Sensor Obstruction: The presence of mud, snow, ice, or even a sticker covering the sensor or the area directly above the rear bumper can impede the sensor's ability to transmit and receive signals.
• Adverse Weather Conditions: Driving on a road surface that is heavily wet with standing water during severe weather conditions such as heavy rain, snow, or dense fog can affect the radar signals and potentially reduce detection accuracy.
• Close Proximity of Multiple Vehicles: If several vehicles are approaching in close succession with only very small gaps between them, the system might struggle to individually identify each one.
• High-Speed Approach: Vehicles approaching at speeds significantly exceeding the system's designed detection range (above approximately 34 mph or 56 km/h) might not be registered in time for an alert.
• External Equipment Obstructing Sensors: Any aftermarket equipment installed that could potentially block or interfere with the radar sensors, such as a towing eyelet that remains attached, a thick bumper protector or trim strip, a bicycle carrier, or a snow plow, can hinder the system's operation.
• Sharp Incline Changes: When backing up on a slope with a sudden or sharp change in the road's gradient, the sensor's angle relative to approaching traffic might be altered, affecting detection.

• Sharp Angle Parking Exit: Maneuvering out of a parking spot at a very sharp angle can sometimes limit the sensors' field of view and reduce detection capability.

• System Initialization: Immediately after the RCTA function is first turned on, or shortly after the EV system of your Toyota bZ4X is started with RCTA enabled, the system might require a brief moment to fully initialize and achieve optimal performance.
• Sensor Obstructions (Reiterated): Obstructions that weren't listed before but still block the sensor's line of sight can prevent vehicle detection.
• Towing: When your vehicle is actively towing a trailer, the dynamics and geometry at the rear are changed, which can impact the accuracy of the RCTA system.
• Significant Vehicle Height Differences: If there is a large difference in height between your 2025 Toyota bZ4X and an approaching vehicle entering the detection area (e.g., a very low-riding sports car or a very tall truck), it could affect sensor detection.
• Extreme Temperatures: If a sensor or the area immediately around it becomes excessively hot or cold, it might temporarily affect the sensor's performance.
• Aftermarket Modifications: Modifications to the vehicle's suspension system or the installation of tires with a significantly different size than those specified by Toyota can alter the vehicle's ride height and sensor angles, potentially impacting RCTA functionality.
• Load-Induced Vehicle Angle Changes: If the front of your vehicle is significantly raised or lowered due to a very heavy load in the front or rear, this change in vehicle pitch can affect the rear radar sensor's orientation.
• Turning While Backing Up: Executing a turn while simultaneously backing up can sometimes complicate the sensor's ability to accurately track and detect crossing traffic.

• Vehicle Entering Detection Area at an Angle: If an approaching vehicle turns sharply into the sensor's detection area, the system might not register it as quickly as a vehicle crossing perpendicularly.

Situations in Which Your 2025 Toyota bZ4X RCTA May Operate Even Without a Collision Risk (False Positives)

In certain scenarios, the Rear Cross Traffic Alert function in your 2025 Toyota bZ4X might inadvertently detect a vehicle or object and issue an alert even if there is no actual risk of a collision. The likelihood of such instances may increase in the following situations:

• Parking Facing a Street: When your parking space is directly facing a public street with regular vehicle traffic, the system might detect vehicles driving along the street as you are backing out.

• Proximity to Metal Objects: If there are large metal objects close to your vehicle while backing up, such as a guardrail, a solid metal wall, a prominent signpost, or a large parked vehicle, these objects can sometimes reflect the radar waves back towards the rear sensors, potentially triggering a false alert.

• External Equipment (Reiterated): As mentioned before, certain external equipment that might partially obstruct the sensors can sometimes cause unexpected reflections or readings leading to false alerts.
• Vehicles Passing By: If a vehicle simply drives past the side of your Toyota bZ4X at a certain speed and proximity while you are in reverse, it might momentarily trigger the RCTA system.

• Turning Detected Vehicle: If a vehicle that is initially detected by the RCTA system makes a turn while approaching your vehicle, the change in its trajectory might sometimes lead to an unnecessary alert.

• Spinning Objects Nearby: The presence of rotating objects in close proximity to your vehicle, such as the fan of a nearby air conditioning unit, could potentially be misinterpreted by the radar sensors.
• Water Spray: If water is splashed or sprayed towards the rear bumper of your Toyota bZ4X, for instance from a sprinkler system, the radar signals could be momentarily affected, leading to a false alert.
• Moving Atmospheric Elements: Moving objects in the air like flags waving in the wind, exhaust fumes from another vehicle, large raindrops or snowflakes during heavy precipitation, or even significant water movement on the road surface itself can sometimes trigger a sensor reaction.
• Proximity to Structures (Reiterated): Similar to metal objects, backing up very close to a guardrail, wall, or other structure that enters the sensor's detection area might cause a false positive.
• Gratings and Gutters: Certain road features like metal gratings or deep gutters can occasionally reflect radar signals in a way that the system interprets as an approaching vehicle.
• Extreme Temperatures (Reiterated): As mentioned before, very hot or very cold temperatures affecting the sensors can sometimes lead to irregular operation, potentially including false alerts.
• Aftermarket Modifications (Reiterated): Modifications to the suspension or non-standard tire sizes can sometimes contribute to unexpected sensor behavior.
• Load Effects (Reiterated): Significant weight distribution causing the vehicle's front to be raised or lowered can occasionally lead to false readings from the rear sensors.
• Towing (Reiterated): As previously mentioned, towing can alter the vehicle's rear profile and potentially cause the RCTA to issue alerts when not strictly necessary.

Understanding the conditions under which the Rear Cross Traffic Alert system in your 2025 Toyota bZ4X might have limitations or produce false alerts is essential for responsible and safe driving. Always remain vigilant and perform your own visual checks when backing up.