Collision Warning and Intervention
Collision warning and intervention systems made news in 2022. In August of that year, six leading organizations that are committed to consumer safety and education — AAA, Consumer Reports, J.D. Power, National Safety Council, PAVE, and SAE — came together to develop the standardized naming conventions for Advanced Driver Assistance Systems (ADAS) technologies.
This page addresses Forward Collision Warning and Collision Intervention System Indicators, a subset of ADAS. We address them directly below.
The newly recommended naming conventions are simple, specific, and based on system functionality. We have advocated for these changes for years and welcome them, but we will continue to include the old names where necessary.
Unfortunately, the absolutely outlandish number of indicators used are not addressed! And the list continues to grow…
Further, it is important to note that the organizations are only asking automakers to adopt the standardized terminology, a move that would go a long way in reducing consumer confusion about the intent and functionality of these systems. We’ll do our best to help here and in other posts.
These systems, and those that follow, are all moving in the direction of Automatic Braking, which all manufacturers have promised to install in all passenger vehicles by roughly 2020.
First systems
PCS stands for Pre Collision, or Crash, System. FCW stands for Forward Collision Warning System. Another is CMBS or Collision Mitigation Brake System. Yet another is the very awkward sounding Pre-safe Seat Belt (PSB) system. This one has a warning image in the message center in gray scale, like the seated figure shown to the right, along with a text warning.
How about Panic Brake Assist (PBA), Forward Emergency Braking (FEB), Predictive Forward Collision Warning (PFCW) or Smart Brake Support (SBS)? They play in the same ball park, but don’t have their own text symbols!
Collision warnings
The end result is yet another advanced system that has managed to resist finding a standardized name. The systems discussed here use radar while others use cameras, which are found on this page as well.
The images above left are indicative of those most commonly seen. We will use them as templates going further.
Audi, Skoda
Audi and Skoda share the same or at very similar indicators. Audi calls its system Pre-sense while Skoda goes with Front Assist. The red indicator for both manufacturers tells of the possibility of an imminent collision. The companies them moved to the black and white indicators. The use of the circle in brackets indicates that these are auto braking systems as the two elements are common to brake symbols.
Pre-sense and Front Assist detect collision hazards around the car and initiates specific safety measures. A given vehicle may have only front, front and rear or 360° options.
Skoda uses a yellow/amber/orange indicator that as an off indicator. The black and white image used by the company simply tells the driver that the system has been activated. Again, the use of the circle in brackets indicates that these are auto braking systems as the two elements are common to brake symbols.
GMC
GMC has adopted a slight variation of the second image seen above as a Collision Warning indicator. It increases the size of the star and the size of the vehicles. In this case, it indicates that the system is off.
Land Rover
Land Rover is claiming Autonomous Emergency Braking (AEB) and is using the warning symbols to the left. Red is seen when AEB is active or a collision threat is detected. Hopefully its the former. In gray, the AEB system is disabled, which does not necessarily mean a fault. A yellow/amber/orange version with the word off likely means blocked sensors or a fault in the system. Click here for more.
Regardless of name or acronym, the systems, if fitted, minimize the risk of injury if a crash becomes unavoidable. The vehicle will alter its suspension and brake settings (apply the brakes) and the front seat belts are tightened.
Maserati, Dodge
Maserati and Dodge use the image with two vehicles seen above in yellow/amber/orange and then added the image to the left that eliminates the vehicle in front. Using the same color scheme, they indicate the system is turned off and is not in fault mode.
Smart
Mercedes-Benz Smart division uses very similar symbols to those above, changing the shape of the vehicles to match the Smart models. The back of a second vehicle is added and the word OFF is added. It is seen in yellow/amber/orange.
Vauxhall
Vauxhall uses both the red and the yellow/amber/orange versions of the first symbol above and seen at the left. The choice depends on the distance between the vehicles. The indicator goes to red as the distance shrinks.
Pre-Collision Assist
Another recent (2024) addition is this Pre-Collision Assist indicator. Pre-collision assist detects and warns of approaching hazards in the road and provides multiple levels of assistance to help avoid a collision if you are rapidly approaching another stationary vehicle, a vehicle traveling in the same direction, or a pedestrian or cyclist in your path. The system offers an alert first, then brake support and automatic emergency braking, if needed.
The image with the line drawn through it says that the system is malfunctioning. Continue on for additional information regarding system problems.
Newer Collision Warning System Versions
The images here are of a Collision Warning System active and another with the word OFF added, meaning the system has been deactivated. They are seen as a car in a lane with wavy lines radiating away in four directions. And the word OFF in the one case, the first two in red.
It is important to note that many systems can only warn of a potential collision audibly and take no active measures to protect you. Check your owners manual carefully. And regardless of whether the system is active or not, it should never be relied upon to avoid a collision without the driver’s help!
Audi and Skoda
Audi and Skoda share the or at least similar indicators. Audi calls its system Pre-sense while Skoda goes with Front Assist. The red indicator for both manufacturers tells of the possibility of an imminent collision. The companies them moved to the black and white indicators. The use of the circle in brackets indicates that these are auto braking systems as the two elements are common to brake symbols.
Pre-sense and Front Assist detect collision hazards around the car and initiates specific safety measures. A given vehicle may have only front, front and rear or 360° options.
Skoda uses a yellow/amber/orange indicator that as an off indicator. The black and white image used by the company simply tells the driver that the system has been activated. Again, the use of the circle in brackets indicates that these are auto braking systems as the two elements are common to brake symbols.
Dirty Sensors
A common problem is dirt on the sensors or cameras in the front of the vehicle and often a simple car wash or cleaning will resolve the issue. The symbol to the left showing an arrow piercing the top side of a car is used by manufacturers for what they call the City Safety System to indicate that sensors mounted in the windshield are blocked by dirt or debris.
The first symbol in this set also points to debris blocking the camera at the front of the vehicle, and again a car wash is likely all that is needed. This, and the next two symbols, are the only ones to attempt a representation of seeing. They are also in black and white and will be displayed in the information screen along with a text description of the problem. The image, unlike the next two gives no indication itself of a problem.
System Off Indicators
These symbols indicate that the Forward Collision Warning system has been turned off. Some manufacturers use the picture symbol with the word OFF, while others add OFF to the system’s acronym. The image symbols are intended to look like cars crashing into each other, and does the job.
The symbol to the left, which adds the exclamation point in the triangle alert and an arrow indicating the direction of travel, illuminates when the brakes are applied automatically, which would be an obvious distraction to the driver at a clearly bad time. The exclamation point does not imply a malfunction, as is commonly the case.
More Fault Indicators
If any of these lights remain illuminated, it indicates a problem with the system that will require your dealer or authorized service center to resolve. The light to the left is a trouble light only. See your favorite service center. And note that if there are any additional illuminated warning symbols, most likely they will need to be addressed first.
These indicators to the left are Front-end Collision Warning indicators, although the symbols show the back-end of a car. The manufacturers use the same symbol for both a warning that the system has a problem or if a collision is imminent. We’ve shown them d, which is used when a potential collision is detected. It may flash red as the condition worsens and/or when the relative speed between the two vehicles is large.
It will illuminate in yellow/amber when associated with the Active Cruise Control system and a vehicle driving ahead is detected. The indicator will flash if the system is not operating properly. In this case, the active cruise control will be deactivated and the brakes will be applied until the driver resumes control by either pressing on the brake or accelerator pedal.
Rear and Side Collision Indicators
Note that we have separated Rear Collision Indicators to a separate page here. An example is to the right. In these cases, the vehicle shown in front is seen in full. In most forward collision indicators, the vehicle at the rear is seen in full.
Also, if you are seeing an image in red of a vehicle fully from the side, it is likely a Side or Intersection Collision Warning Indicator, which we have moved to a separate page here.
Emergency Steering
We have now also separated Emergency Steering Warning Indicators to its own page here. This page was simply going out of control. So, if you see a steering wheel above the rear vehicle, its a Steering symbol.
Fault Indicators
Fault Indicators for Collision Avoidance Systems have now been separated out into their own page. If you’re seeing an indicator with an exclamation point inside like the one to the right, this is likely to be the page you need.
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The information on this website is provided for information sharing purposes only, and should not be used in lieu of an OEM service manual or factory authorized service procedure. We are not in the auto repair business nor do we publish automotive service manuals. Nothing we include on these pages and posts has been reviewed, approved or authorized by any vehicle manufacturer.
Remember that only proper service and repair procedures will ensure the safe and reliable operation of your car. In addition, proper safety procedures and precautions, such as the use of safety goggles, the right tools and the equipment should be followed at all times to eliminate the possibility of personal injury or improper service which could damage the vehicle or compromise its safety.
Technology is always changing and what is current and accurate today may be literally out-of-date and inaccurate tomorrow. And when it comes to the current state of flux in the auto industry, nothing is more true.
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The author has 30+ years of automotive experience and has assembled the most extensive collection of symbols and warning lights anywhere (over 1,000!) and can help you open and start any keyless start car with a dead key fob battery. BA, St. Joseph’s, ME: MS, RPI, NY