Making sense of Toyota's "Safety Sense"

July 1, 2019
Here’s an overview of TSS — found on every new model Toyota vehicle — and information on its diagnosis and repair.

The push toward autonomous vehicles is driving vehicle manufacturers to create and implement integrated technology packages that are aimed at assisting the driver. These safety packages are commonly referred to as Advanced Driver-Assistance Systems or ADAS. Toyota Safety Sense (TSS) and Lexus Safety System (LSS) are the proprietary names Toyota is using for their ADAS systems. While these systems are currently designed to support the driver, the foreshadowing towards autonomy is evident. The challenge for today’s repair and collision facilities in diagnosing, repairing and calibrating these vehicles will include the need for proper training, service information, scan tools and related tooling.

(Image courtesy of Toyota Media) Toyota Safety Sense is Toyota’s advanced driving assist system.

The complication to this technology on Toyota and Lexus vehicles comes down to the differences in system buttonology and display technology found on each varying vehicle. It has been rumored that Toyota and Lexus are on their fifth generation of this technology adding to the complexity of diagnosis and repair. For example, Toyota Safety Sense has gone under the name TSS-C, TSS-P and the Current TSS 2.0. These formal TSS classifications come after years of utilization of millimeter wave radar systems found on Lexus vehicles and Toyota nameplates such as Sequoia and Prius.

The push toward autonomy

While most manufacturers are forging toward a driverless future, most are still sure to tell their customers that this is an assist feature and not a replacement for the vehicle’s driver. The Society of Automotive Engineers recently published a chart that outlies the six classification from fully driver operated vehicles to fully autonomous vehicles. Level “0” representing the former while level “5” the latter. Most manufacturers, including Toyota find themselves in the level 1-2 range with still quite a few complications and hurdles to overcome before moving up in level.

(Image courtesy of Toyota Media) Toyota’s TSS-C and TSS-P were the predecessors to TSS 2.0.

A look at the current Toyota Safety System reveals the current level of technology as well as some of the obstacles to full autonomy.

Pre-Collision System with Pedestrian Detection
The pre-collision system with pedestrian detection utilizes a forward facing, windshield mounted camera as well as a millimeter wave radar sensor typically mounted in the Toyota or Lexus emblem in the vehicles grille. This technology is designed to detect hazards and / or pedestrians between speeds of 7-110 mph for the pre-collision and 7-55 mph for pedestrian detection and will alert the driver to hazards both audibly and visually with a series of beeps and a flashing warning to brake. If the driver brakes in response to this warning the system will often provide additional brake force to bring the vehicle to a stop more quickly. If the driver does not brake at all, the system may apply the brakes for the driver automatically.

(Image courtesy of Toyota Media) Toyota’s TSS 2.0 features upgrades such as pedestrian detection

While the idea of this system is very well intended, Toyota specifically points out that there are multiple scenarios in which this technology is unreliable. Specifically, the system relies on straight roadways, and clear visibility. If visibility is poor such as in bad weather, the system may be unreliable. Additionally, the sudden appearance of a vehicle or other object, uneven roadways or sharp curves, something on the sensor, strong sunlight or the ability to see motorcycles or bicycles all provide complications to system reliability.

Toyota is sure to issue the disclaimer – that drivers are responsible for operating their own vehicles.

(Image courtesy of Toyota Media) Pre-collision systems detect closing targets, provide warning and ultimately brake.

Land Departure Alert
Tired or distracted driving that causes a driver to swerve out of their lane is mitigated through the use of lane departure alert. LDA typically activates when the system observes the driver veering out of a visibly marked lane. This system utilizes a forward-facing camera to detect the lines on the road. Above a speed of 32mph with the system enabled and on a reasonably straight road, the system will provide an audible and visual warning to the driver. Some vehicles are also equipped with steering assist that will provide slight adjustments in an attempt to keep the vehicle in the lane. Many of these functions are adjustable and, in some cases, can be turned off entirely.

This system, as will its pre-collision relative, is highly dependent on the windshield mounted camera. It works best on straight roads and when lane markers are clearly visible.

Toyota warns to not overly rely on this technology as it will not work in every situation. Poor visibility of the camera in bad weather or due to bugs, dirt, ice, frequent or shar curves, oncoming headlights, bright sunlight and poorly marked lanes will all effect operation.

Automatic High Beams
The automatic high beam system utilizes the forward-facing camera to automatically switch between high and low beam operation to maximize visibility for the driver while limiting the interference of high beam lighting on other drivers. This system utilizes the camera to detect light levels and can sense oncoming headlights and tail lights from vehicles.

(Image courtesy of Toyota Media) Automatic High Beams add a layer of safety through improved visibility

Dynamic Radar Cruise Control
TSS vehicles come with dynamic radar cruise control. This system operates like traditional cruise control but adds a feature of distance control from the vehicle in front of you by adjusting speed to maintain distance. This system has an overall operating range from 25-110 mph. A speed above 28mph is required to initiate. There are also full speed range on some models that will allow the vehicle to come to a complete stop if the vehicle in front of it stops. This system is operated through the use of the millimeter wave radar sensor located in the emblem.

(Image courtesy of Toyota Media) Radar Cruise utilizes millimeter wave radar located in the front emblem.

Road Sign Assist
Road sign assist is a new feature for TSS 2.0 and is designed to read certain traffic signs and display them on the vehicle multi-function display. The signs it is capable of recognizing and displaying include speed limit, stop yield and do not enter signs.

Lane Tracing Assist
New with the 2019 corolla hatchback, lane trace assist combines LDA and DRCC technologies to enhance the vehicles ability to remain centered in a lane and at a safe distance. This system requires the driver to be an active participant and requires the driver’s hands to be on the steering wheel. Failure to do so will result in a visual warning.

Blind Spot Monitoring
While not a formal part of the Toyota Safety Sense suite of technologies, Blind Spot monitoring is another technology that alerts the driver to vehicles not visible in mirrors. Not all vehicles are equipped with this technology but a button with “BSM” to the left of the steering wheel is the way of determining if this system is present.

In summary, the TSS suite of safety systems provides a wealth of technologies to support the driver. However, the technology has a way to go. For instance, how will an autonomous vehicle handle the complexity of America’s roadways with complex geography and various nuances in State to State infrastructure. New Jersey’s right hand turn to make a left comes to mind. On an even more basic level, how will weather and mother nature be compensated for?

Service Information

Factory service information is critical in the diagnosis, service and repair of Toyota/Lexus ADAS systems. Many of the vehicles that independent shops will encounter will still be under warranty adding an extra layer of consideration before proceeding with service procedures of any kind. As with any technology, ADAS is constantly evolving and there are now several generations of ADAS related equipment found across the Toyota and Lexus product line. As mentioned previously there are multiple generations and various nuances even within the same model year. With these considerations, accessing Toyota Service Information will be critical.

Quick Training Guides found in TIS provide critical service information such as space requirements for calibration.

Toyota makes their service information readily available to the independent repair market via a paid subscription at: $20 dollars for a two-day subscription will provide you with the full suite of Toyota and Lexus service information, wiring diagrams, service bulletins and supporting materials such as technical training guides and Quick Training Guides. Monthly and yearly subscriptions are also available.  These resources provide a wealth of information for the independent repair facility and will ensure that any work related to ADAS will be done by the book

Before proceeding with any service related to ADAS be sure to consult Technical Service Bulletins as there are many related to the ADAS system that will be relevant to basic ADAS procedures such as calibration. For example, there are several Lexus models that have TSB’s related to the angle of the shop floor and how to compensate for this phenomenon when calibrating the system.

Toyota and Lexus Quick Training Guides also provide valuable insight into the calibration of Toyota and Lexus ADAS systems. Think of these Quick Training Guides as a “Greatest Hits” document that includes snippets of information from the repair manual, New Car Features Guide, Electronic Wiring Diagrams and more. As such, they are a massive time saver and a “go-to” guide for technicians.

Quick Training Guides provide a wealth of information on TSS system functions.

When is Service Required?

The service of the TSS system typically relates to scenarios in which either the camera, millimeter wave radar, sonar or alignment may have been altered due to collision, replacement of parts or regular service. When in doubt, consult the service information.

Required tools

Included in Quick Training Guides are the service tools required.

At a recent Instructor training event for the national Toyota T-TEN program, many of us were surprised to see a plumb bob and laser level amongst the “special tools” required when performing calibration functions of the TSS system. The plumb bob is utilized to find the center line by locating the center of the emblem in the front and rear of the vehicle and marking center on the floor at the location of the plumb bob. Then the center line of the vehicle can be projected with the laser level to the specified distance in the service information. While low-tech, it works well.

In addition to these easy to find tools, calibrations will require an appropriate scan tool and targets for both the camera and millimeter wave radar. The targets can be printed through the service information and some related TSB’s meaning the only piece that will have to be truly sourced is the diamond shaped reflector for the millimeter wave radar calibration.

There are quite a few companies out there that are beginning to design ADAS calibration systems to work with multiple manufacturer vehicles. Currently in production are systems by Autel, Bosch and Hunter Engineering while many others are rumored to be working on their own solutions.

Other considerations

Performing TSS calibration functions may sound like a new line of income for your business but proceed with caution. Most Toyota dealerships in the metropolitan New York region are charging 2.5-3 hours labor for this service. The complication is that some dealers are unable to perform these functions. Why, you might ask? Because some of the service functions require a flat, level surface with a significant distance of up to 20 feet in front of the vehicle. Add to this the need for good lighting and limited objects in the background during the aiming process and you have eliminated every small dark service facility in the country.

Toyota Safety Sense 2.0 captures the present-day safety features found on Toyota vehicles in 2019. As the saying goes – The only constant is change. You can expect that by this time next year there will be more to write about. In the meantime, consult

Voice Your Opinion!

To join the conversation, and become an exclusive member of Vehicle Service Pros, create an account today!