ADAS Calibration: Why Rear Radar Sensor Calibration is Essential

With the proliferation of ADAS features in vehicles of all kinds, it’s encouraging to see that systems such as Rear Cross Traffic Alert (RCTA) and Rear Cross Traffic Braking are drastically reducing accidents.

Therefore, it's important that you and your shop understand rear radar sensors, how they function, and their needs. Not only is servicing ADAS features a prerequisite to keep your shop ahead of the competition, but doing so efficiently and correctly will secure you more revenue. 

Read on to learn about rear radar sensors—which ADAS systems rely on—their calibration requirements, potential issues you may face during the process, and the importance of this knowledge for your shop.

Understanding Rear Radar and RCTA Systems

Rear radar sensors are located on the back of a vehicle, typically equipped on the bumper. They emit radio waves to detect other vehicles or obstacles from the rear or side of the vehicle. 

ADAS features such as Blind Spot Monitoring (BSM) and RCTA rely on the proper function of these rear radar sensors.

What is RCTA (Rear Cross Traffic Alert)?

RCTA is an ADAS feature that assists the driver in detecting traffic when reversing. It makes reversing safer and is especially useful in limited visibility situations, like reversing from a parking space.. It increases situational awareness, creates safer maneuvers, and integrates with other ADAS features to reduce collisions and increase overall safety.

The difference between Rear Cross Traffic Alert, Traffic Braking, and Collision Warning (RCW)

RCTA is unique from Rear Cross Traffic Braking or Rear Collision Warning (RCW). While all three function thanks to the rear radar sensors, it’s important to understand what each is trying to accomplish.

Rear Cross Traffic Alert

• Detects oncoming perpendicular traffic from behind only while in reverse
• Uses radar sensors on the sides of the rear bumper

Rear Cross Traffic Braking

• Detects traffic in the same way as RCTA
• Can automatically apply the brakes to avoid a collision

Rear Collision Warning

• Constantly monitors for rear-end collisions from directly behind at all times
• Typically uses rear radar sensors, but some manufacturers use ultrasonic, camera, or Light Detection and Ranging (LIDAR) sensors on the center rear of the car

Understanding the difference between these three systems is vital to appreciating the versatility and importance of rear radar sensors. Properly calibrating these sensors requires unique care to ensure their intended function.

Common vehicles equipped with rear radar sensors and car RCTA systems

With the direction of the auto industry, you will be pressed to find a new vehicle that doesn’t have rear radar sensors. One example is Tesla, which has removed rear sensors from most of its new models, opting for its camera-based “Tesla Vision” system.

That being said, not all rear radar sensors are built the same, and different manufacturers mean that related ADAS features can vary from vehicle to vehicle. Being educated on the variance of these sensors and their dependent features is a must in the collision industry.

Some manufacturers, such as Chevrolet, integrate their RCTA with Rear Cross Traffic Braking, whereas Toyota integrates RCTA and BSM. Others, such as Ford, equip rear radar sensors that allow RCTA to function at high speeds, whereas Volkswagen’s sensors offer a wider degree of monitoring. Because of the variance in function and quality of rear radar sensors from one manufacturer to another, your shop must be equipped with the know-how to service all makes and models.

Why Rear Radar Sensor calibration is critical

So, what do rear radar sensors have to do with you and your shop?

Simply put, ADAS calibration is a requirement for many of these systems, not optional. That means knowing the ins and outs of rear radar sensors is a must. Having a proper calibration process can mean freedom from liability, increased revenue, higher customer satisfaction, and successful insurance payouts.

Let’s look into why your shop must know how to service rear radar sensors.

The role of Rear Radar in ADAS

Rear radar sensors are central to many ADAS systems that we already covered, such as RCTA, BSM, Rear Cross Traffic Breaking, and RCW. 

Another ADAS system powered by rear radar sensors includes Active Lane Change Assist, which helps drivers monitor traffic and determine when changing lanes is safe.

Rear radar sensors are vital to the function of these various ADAS systems. ADAS relies on a whole network of sensors, including these, to make decisions. Sensor fusion is the communication between various sensors and the car’s central computer. All sensors need to work in unison to ensure proper function and safety.

When Rear Radar calibration is required

When do rear radar sensors need to be calibrated?

Perhaps surprisingly, these sensors need to be calibrated often. Many collision-related and non-collision triggers require you to calibrate the rear radar sensors. These sensors are delicate and require specific height and angle measurements to function properly.

Non-collision triggers include: 

• Rear bumper removal and reinstallation
• Suspension modifications
• Wheel alignments and tire changes

Collision-related triggers include: 

• Rear-end collisions (“fender benders”)
• Damage to axles
• Service to the vehicle that impacts the ride height

Minor changes to vehicle geometry can have an impact on rear radar function, and subsequently, numerous ADAS features. Your technicians need to recognize the many different triggers for rear radar calibration.

Risks of skipping or improper Rear Radar calibration

Improperly calibrating rear radar sensors or skipping this step altogether can have disastrous results on a vehicle’s performance and safety. Improperly calibrated rear radar sensors will cause numerous ADAS features to malfunction, which puts your shop at risk for various reasons.

First off, you could be held liable for accidents in which these sensors failed. You must perform and document all necessary services to ensure the function of equipped ADAS systems. Failure to do so could land your shop in a legal mess, not to mention putting your customers at risk of injury.

Second, poor service means less business. Subpar customer satisfaction is a surefire way to miss out on potential revenue. Imagine a scenario in which a customer is unhappy that their safety features are not working as intended. Not only do you miss out on their future business, but they are unlikely to recommend your shop to friends and family.

Challenges collision shops face with RCTA calibration

While there are challenges you may face when calibrating rear radar sensors, it's important to note that there are also solutions. To find these solutions, you must first be able to identify issues and create game plans for dealing with them.

One of the biggest complaints from technicians is that rear radar sensor calibration lacks standardization. Many makes and models require different ride heights and angle measurements, presenting headaches. This non-uniformity can be aggravating, but with tools like Revv, you will know exactly the requirements for each vehicle without thumbing through hours of documentation.

The time factor is also a challenge in calibration. From diagnosing to servicing, checking standards, and verifying service, manual calibration takes a long time. Ensuring you are following OEM procedure and documenting each step manually adds hours to your workflow. Revv can also help shave this time off, instantly pulling up current and accurate OEM procedures and generating all the necessary documentation you need to let your technicians focus on the task at hand.

Revv eliminates the stress from worrying about liability and compliance risks as well. As Revv automatically generates the correct documentation, you will never worry that you are following the right procedure again. Your mind will be at ease, turnover will increase, and so will your revenue.

Stay competitive in the age of ADAS

By 2021, 41% of With the success of these ADAS systems, it’s a foregone conclusion that they are here to stay.  registered vehicles were equipped with rear radar sensors. This number is expected to rise to 60% by 2026, bringing with it a surge in demand for accurate ADAS calibration. 

Is your shop equipped to handle the continued surge in ADAS integration? You need a software partner that will enhance your workflow and raise your revenue. Choosing the correct partner is key, and Revv is here to take your shop to the next level.

With Revv, you will have access to:

• Instant identification of required calibrations
• Detailed OEM procedures
• Comprehensive documentation tools
• The ability to seamlessly integrate into current workflows and with existing shop systems

Revv has already done the tedious work; your technicians can focus on calibrating rear radar sensors with their full attention. Set up a call with our team and see how Revv ADAS can improve your shop by capturing more revenue and keeping your customers safe.