Ask Joe Mechanic: Collision Avoidance Systems, Part II

                  This week we continue collision avoidance systems coverage with information on the Asian and European brands. While information on domestic manufacturer’s systems was sparse at best, and while the same was true of many of the import brands, one stood out by offering a wealth of information.

                  Toyota Motor Corporation's Pre-Collision System (PCS), the first production forward-warning collision system, is used on the manufacturer's Lexus and Toyota brand vehicles. It is a radar-based system that uses forward-facing millimeter-wave radar. When the system determines that a frontal collision is unavoidable, it preemptively tightens the seat belts, removing any slack, and pre-charges the brakes using brake assist to give the driver maximum stopping power instantly when the driver depresses the brake pedal. Toyota launched PCS in February 2003 on the redesigned Japanese domestic market Harrier, and in August 2003 added an automatic partial pre-crash braking system to the Celsior.

                  In September 2003, PCS made its first appearance in North America on the Lexus LS 430, becoming the first such system offered in the US. In 2004, Toyota advanced the system by adding to the radar a single digital camera to improve the accuracy of collision forecast and warning and control levels. It was first available on the Crown Majesta (Avalon). In 2006, the debut of the Lexus LS featured a further advanced version of the PCS; this newer version, dubbed Advanced Pre-Collision System (APCS), added a twin-lens stereo camera located on the windshield and more sensitive radar to detect for the first time smaller "soft" objects such as animals and pedestrians. A near-infrared projector located in the headlights allows the system to work at night. By using the LS's Adaptive Variable Suspension (AVS) and electric Variable Gear Ratio Steering (VGRS), the system can change the suspension damper firmness; steering gear ratios and torque assist to aid the driver's evasive steering measures in a system known as "Collision-Avoidance Steering Support". The Lane Keep Assist system will make automatic steering adjustments to help ensure that the vehicle maintains its lane in case the driver fails to react.

Also unveiled for the 2007 model year, the world's first Driver Monitoring System was introduced on the Lexus LS, using a CCD camera on the steering column. This system monitors the driver's face to determine where the driver is looking. If the driver's head turns away from road and a frontal obstacle is detected, the system will alert the driver using a buzzer, and if necessary, pre-charge the brakes and tighten the safety belts. A later version of the Driver Monitoring System found in 2008 on the Crown monitors the driver's eyes to detect the driver's level of wakefulness. This system is designed to work even if the driver is wearing sunglasses, and at night.

Other advancements to the PCS appearing on the 2007 Lexus LS include the first rearward-facing millimeter-wave radar mounted in the rear bumper. This system adjusts the active head restraints by moving them upward and forward to reduce the risk of whiplash injuries if an imminent rear collision is detected.

                  Toyota began using Night View on the JDM 2002 Toyota Landcruiser Cygnus and on the 2003 Lexus LX 470 available in the US market. In 2008, Toyota added a pedestrian-detection feature on the Crown, which highlights pedestrians and presents them on an LCD display located in front of the driver. The latest Crown also uses a GPS-navigation linked brake assist function. The system, which is designed to determine if the driver is late in decelerating at an approaching stop sign, will then sound an alert and can also pre-charge the brakes to provide optimum braking force if deemed necessary. This system works in certain Japanese cities and requires Japan specific road markings that are detected by a camera.

In March 2009, on the redesigned Crown Majesta, Toyota again further advanced the PCS, adding front-side millimeter-wave radar to detect potential side collisions primarily at intersections or when another vehicle crosses the centerline. The latest version tilts the rear seat upward, placing the passenger in a more ideal crash position if it detects a front or rear impact.

Honda’s Collision Mitigation Brake System (CMBS) was originally introduced as “CMS” in 2003 on the Acura brand in the U.S. and Canada. It utilizes a radar based system to monitor ahead and provide automatic braking if the driver does not react to the instrument panel warning and tightening of the seat belts. Honda had the first production system to offer automatic braking and also incorporate “E pretensioner” electric tensioning of the front seatbelts. When activated, CMBS has three stages, first being audible and visual warnings to brake. In the second stage, the “E pretensioners” activate to encourage action. In stage three, with collision imminent, all seat belt slack is taken up and automatic brake activation takes place to lessen the severity of the crash.  In late 2004, Honda also introduced an Intelligent Night Vision System, which highlights pedestrians in front of the vehicle by using an audible chime and an image displayed on the Heads Up Display.

Mazda uses a system that they have named Smart City Brake Support, which uses lasers to detect vehicles or obstacles ahead of your vehicle. This system will apply braking and cut engine power in case of impending collision, and can usually avoid a collision if the speed differential between vehicles is less than 15 miles per hour.

Nissan and Infiniti offer a laser-based system on U.S. market cars, which pressurizes the braking system for maximum brake force. The system also uses adaptive cruise control sensors for some pre-crash data.  In 2008, Subaru introduced “Eyesight” on home market Legacy’s and Outback’s. This system used two CCD stereo cameras mounted on each side of the rear view mirror. The system also has lane departure warning and adaptive cruise control functions. In 2014 all Legacy, Forester and Impreza models worldwide now have the system and it was further upgraded using cameras which can detect intense color such as brake lights for input. These systems are only available on automatic and CVT transmission vehicles.

Audi’s system (Pre-Sense Plus) works in four phases. In the first phase, the system provides warning of an impending accident, while the hazard warning lights are activated, the side windows and sunroof are closed and the front seat belts are tensioned. In the second phase, the warning is followed by light braking, strong enough to win the driver's attention. The third phase initiates autonomous partial braking at a rate of 3 m/s² (9.8 ft/s²). The fourth phase decelerates the car at 5 m/s² (16.4 ft/s²) followed by automatic deceleration at full braking power, roughly half a second before projected impact.

A second system, called (Pre-Sense Rear), is designed to reduce the consequences of rear-end collisions. The sunroof and windows are closed and seat belts are prepared for impact. The optional memory seats are moved forward to protect the car's occupants. The system uses radar and video sensors and was introduced in 2010 on the 2011 Audi A8.

Fiat’s “City Brake Control” is designed as just that, a low speed crash sensing system designed for under 20 miles per hour. The system uses a “Lidar” laser sensor at the top of the windshield to perform a three step process. First detection activates an ABS pre-charge, second step enhances hydraulic brake assist sensitivity, and finally, automatic braking and audible warnings.

Mercedes' “Pre-Safe” system was unveiled in the fall of 2002 at the Paris Motor Show on the 2003 S-Class. Using ESP sensors to measure steering angle, vehicle yaw and lateral acceleration and Brake Assist (BAS) sensors to detect emergency braking, “Pre-Safe” can tighten the seat belts, adjust seat positions including rear seats (if installed), raise folded rear headrests (if installed) and close the sunroof if it detects a possible collision (including rollover). A later version of the Pre-Safe system was supplemented by an additional function that can close any open windows if necessary.

Pre-Safe Brake, Mercedes-Benz's first forward warning collision system, introduced in the fall of 2005 on the redesigned 2006 W221 S-Class, is cooperating with simultaneously introduced Brake Assist Plus (BAS Plus) and Distronic Plus systems and provides all the functions of previous Pre-Safe system while adding a radar-based system that monitors the traffic situation ahead and provides automatic partial braking (40%, or up to 0.4g deceleration) if the driver does not react to the BAS Plus warnings and the system detects a severe danger of an accident. At the 2009 North American International Auto Show, Mercedes unveiled “Attention Assist” on the 2010 E-class, which, based on 70 parameters, attempts to detect the driver's level of drowsiness based on the driver's driving style. This system does not actually monitor the driver's eyes. Also in 2009, Mercedes added the first fully autonomous braking feature that provides maximum braking force approximately 0.6 seconds before impact.

In 2013, Mercedes updated Pre-Safe on the redesigned W222 S-class. Pre-Safe added pedestrian detection, and a system called Pre-Safe Plus uses a rear radar, which tightens the seat belts, flashes the rear hazard lights and applies braking to minimize collision occupant forces. Pre-safe, also with pyrotechnic pretensioners, will tension the seat belt just prior to the collision.

                  Volvo’s “Collision Warning with Automatic Braking” was introduced on the 2007 S80. The system is operated through a radar/camera fusion and provides a Heads-Up display warning that looks like brake lights. If the driver does not react, the system precharges the ABS and increases brake assist sensitivity to maximize driver braking. Later versions can then perform automatic braking, especially in impending pedestrian impact situations. Volvo now introduced the first cyclist detection system in 2013. All Volvo’s systems are laser based.

Ask Joe Mechanic: Collision Avoidance Systems

         A collision avoidance system is an automotive safety system designed to reduce the severity of an accident. Please note what that statement said, it is designed to reduce the severity, not prevent or avoid an accident. The reason for this is because, number one, by the time the system takes over control, and there is a high likelihood that an accident can no longer be avoided. Number two; the system is limited in its capabilities of what it can do in the very brief time that it has to react to the situation. These systems are also known as pre-crash systems, forward collision warning system or a collision mitigating system.  The systems use sophisticated technologies such as radar, laser, cameras and ultrasonic sensors to gather and store information of an imminent crash. Once the detection is done, the systems analyze and compute the data and either warns the driver of an imminent collision, or the vehicle will take independent action by braking, steering or both.

            Since 2009, the National Highway Traffic Safety Administration (NHTSA) has been working independently, along with cooperative efforts with Euro NCAP to study whether to make frontal collision warning systems and lane departure warning systems as mandatory safety equipment on all vehicles. In 2011, the European Commission made a determination to require Advanced Emergency Braking Systems on all commercial vehicles of new design introduced after November 2013, and for all new vehicles built after November 2015 in the European Union. Their impact assessment at that time determines a possibility of saving 5000 lives and 50,000 serious injuries per year across the European Union.

            In 2012, an IIHS study found that two particular collision avoidance systems seemed to hold the biggest promise for immediate benefits. First, autonomous braking where the car would brake on its own if the driver does not react to avoid an impending collision, and second, adaptive headlights which would shift the headlights in the direction that the driver steers. Surprisingly, it was felt that at that stage of development, lane departure systems did not appear to be helpful, and in some cases, even harmful. This shows that even these new safety systems, designed to make our cars safer for us to operate, can sometimes over think, and need to be reigned in somewhat until technology catches up.

The technology in this category is changing almost every month. New models are being added almost every week, and the features and how the systems operate are constantly evolving. Some of the brands have actually gone to entirely new operating systems as they have determined that what they were using is being deemed obsolete. Because of this, much of the information that is available online is already out of date and not reliable. This is a feature that if you want more information, it is best to research online with the manufacturer’s website, if they post the information. Much of this information is closely guarded and not readily available to the average person as it is highly technical and most manufacturers are afraid of corporate spying.

            This week, I will give what basic information I was able to obtain on two domestic manufacturers, Ford and General Motors, and although Chrysler has its own system, I did not find any available information on the basics of how it works.  Ford’s Collision Warning with Brake Support was introduced in 2009 on the Lincoln MKS and MKT and on the Ford Taurus. The system provides a warning through a heads up display that appears resembling brake lights. If the driver does not react to the signal, the system will pre-charge the ABS braking and increase the brake assist sensitivity to maximize driver braking. Ford’s Obstacle Avoidance technology employs a mix of sensors including a camera behind the rearview mirror to scan for vehicles, pedestrians and obstacles and will steer away if the driver does not take action. Ford is currently working with a number of European automakers on a newer version of this system, which is much more sophisticated, using three radar sensors, ultrasonic sensors and a new camera able to scan out up to 650 feet.

            GM’s collision alert system is featured on the 2012 GMC Terrain, among other models, and uses camera technology to scan if there is a vehicle ahead or a lane departure.  The 2013 Cadillac ATS, XTS and SRX models feature low-speed automatic braking.  The 2014 Chevrolet Impala uses radar and camera based information to detect a possible threat and alert the driver. If the driver does not react or reacts too slowly, the system will intervene and apply braking to avoid a collision. The system will alert to forward collision, lane departure, and side blind zone alert and will indicate with LED signals on the dash or outside mirrors.

In the next post, I will address the systems by European and Asian manufacturers.

Ask Joe Mechanic: Current Recalls

We will return to our regular content next week.  This week will again feature the most current recalls that are listed on www.nhtsa.gov.  If after reviewing the recalls below, you discover that you own an affected vehicle, please contact your local dealer at your earliest convenience.  Your dealer will be able to tell you how to proceed with your automobile. 

This Week’s (11/4/14) Recalls:

Nissan North America, Inc. (Nissan) is recalling certain model year 2014 Infiniti Q50 hybrid vehicles manufactured December 10, 2012, to June 25, 2014, and Infiniti Q70 hybrid vehicles manufactured November 7, 2013, to May 7, 2014. Due to a software error, the electric motor may stop working while the vehicle is being driven using the electric motor only.  The stall-like condition that occurs when the electric motor stops working may increase the risk of a crash.

Nissan North America, Inc. (Nissan) is recalling certain model year 2014 Infiniti Q50 hybrid vehicles manufactured October 16, 2013, to January 27, 2014, and Infiniti Q70 hybrid vehicles manufactured November 7, 2013, to December 10, 2013. The affected vehicles may have been assembled with transmissions whose housings were damaged during their manufacturing.  The damaged housings could crack and fracture, creating road debris and disabling the vehicle, increasing the risk of a crash.

Toyota Motor Engineering & Manufacturing (Toyota) is recalling certain model year 2014 Toyota Avalon, Camry, Sienna, and Highlander and model year 2015 Lexus RX350 vehicles. Fuel may leak from the one of the fuel delivery pipes in the engine compartment.  A fuel leak in the presence of an ignition source increases the risk of a fire.

Chrysler Group LLC (Chrysler) is recalling certain model year 2014 Ram ProMaster vehicles manufactured April 23, 2013, to August 22, 2014. In the affected vehicles, the Tire Pressure Monitoring System (TPMS) may fail to learn the locations of the individual sensors while the vehicle is being driven. As a result, the low tire pressure warning light will illuminate, despite the the tire pressures being within specification. Should one of the tires lose air pressure, the driver would not be notified of the change in air pressure. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard No. 138, "Tire Pressure Monitoring Systems."  If the TPMS light illuminates because the sensors cannot be located, it could mask an actual low tire pressure condition, possibly resulting in tire failure, increasing the risk of a crash.

Chrysler Group LLC (Chrysler) is recalling certain model year 2010-2014 Ram 2500, 3500, 4500, and 5500 trucks manufactured March 27, 2009, to September 5, 2013. In the affected vehicles, the electrical connectors of the diesel fuel heater may overheat.  If the connectors overheat, the fuel heater may leak fuel, increasing the risk of a fire

Chrysler Group LLC (Chrysler) is recalling certain model year 2014 Dodge Durango, and Jeep Grand Cherokee vehicles manufactured October 3, 2013, to April 11, 2014. Due to an issue with the software for the Steering Column Control Module (SCCM), the Electronic Stability Control (ESC) may be disabled.  If the ESC is disabled during certain driving situations, the driver may not be able to adequately control the vehicle, increasing the risk of a crash.

Chrysler Group LLC (Chrysler) is recalling certain model year 2014 Dodge Durango vehicles manufactured June 2, 2013, to June 28, 2014, and 2014 Jeep Grand Cherokee vehicles manufactured October 30, 2012, to April 30, 2014. Due to a fault within the Occupant Restraint Control (OCR) module, the frontal air bags, seat belt pretensioners, and side air bags may be disabled. The malfunction indicator light “MIL” should illuminate to initially warn drivers of a failure.  If the frontal air bags, seat belt pretensioners, and side air bags are disabled, there is an increased risk of injury to the vehicle occupants in the event of a vehicle crash that necessitates use of the passive restraint system.

Mitsubishi Motors North America, Inc. (Mitsubishi) is recalling certain model year 2007-2009 Outlander vehicles manufactured December 15, 2006, to October 31, 2007, and April 16, 2008, to August 22, 2009. In the affected vehicles, the brake light switch may malfunction causing the brake lights to not illuminate during brake application.  Brake lights that are inoperative would not warn other drivers that the vehicle is stopping, increasing the risk of a crash.