SAFETY
The 2012 Acura MDX continues the MDX’s commitment of advancing SUV safety. Standard features include dual-stage, multiple-threshold front airbags, active head restraints for driver and front passenger, front seat belts with automatic tensioning system with load limiters, side curtain airbags and driver and front passenger knee bolsters. In addition, the MDX features the Advanced Compatibility Engineering™ (ACE™) body structure, designed to disperse frontal collision forces to better protect the passenger cabin and improve car-to-car collision safety.
ADVANCED COMPATIBILITY ENGINEERING™ (ACE™)
Like every other Acura vehicle, the 2012 MDX features Advanced Compatibility Engineering™ (ACE™) unit-body design. ACE™ is an exclusive body design that enhances occupant protection and crash compatibility in frontal crashes. The ACE™ design utilizes a network of connected structural elements to distribute crash energy more evenly throughout the front of the vehicle. This enhanced frontal crash energy management helps to reduce the forces transferred to the passenger compartment and can help to more evenly disperse the forces transferred to other vehicles in a crash.
If the MDX should collide head-on with a smaller and/or lighter vehicle, the Advanced Compatibility Engineering™ structure helps provide good engagement with the small vehicle’s frame thanks to a special lower member that extends below the front bumper beam. This lower member helps ensure that if the MDX collides with a smaller vehicle, the lower front member will better engage the other vehicle’s bumper system. This helps reduce the risk of intrusion while simultaneously helping to disperse the crash energy across a wider area at the front of the vehicle.
DRIVER AND FRONT PASSENGER DUAL-STAGE, MULTIPLE-THRESHOLD AIRBAG SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
Dual-stage, multiple threshold front airbags (SRS) are provided for the driver and front passenger. One or both of these airbags will be deployed only in the event of a sufficient frontal impact. If deployed, these airbags are capable of being inflated at different rates depending on crash severity, seatbelt usage and/or other factors. Frontal airbags are designed to supplement the seatbelts to help reduce the likelihood of head and upper body injuries in frontal crashes.
Dual-Stage, Multiple-Threshold Airbag Parameters
- Airbag deployment thresholds are controlled depending on the severity of a collision, driver seat position, passenger weight, and the seatbelt buckle status of both occupants.
- The dual-stage, multiple-threshold strategy applies to front airbags only and does not affect operation of side airbags or side curtain airbags.
The MDX airbag system uses a sensor to assess the weight of the front seat passenger. The front passenger airbag is shut off if the weight sensor indicates that a child or small statured person is occupying the front seat. In addition, the driver’s seat has a seat position sensor: if the seat is in a more forward position (where the occupant will be close to the airbag), the airbag is fired with a longer delay to reduce the chance of injury caused by the airbag itself. A laser-cut, seamless instrument panel cover fully conceals the instrument panel-mounted passenger airbag while the driver-side front airbag is housed within the steering wheel.
DRIVER AND FRONT PASSENGER KNEE BOLSTERS
To help reduce the likelihood of injuries to the driver or front passenger’s legs in a frontal collision, the MDX has energy-absorbing knee bolsters. The bolsters are designed to help dissipate collision forces if the driver or front passenger’s legs should contact the lower instrument panel during a frontal collision.
DRIVER AND FRONT PASSENGER SIDE AIRBAGS WITH FRONT PASSENGER OCCUPANT POSITION DETECTION SYSTEM (OPDS)
Side airbags mounted in the outboard portion of each MDX front seatback are designed to provide torso and pelvis protection in the event of a severe side impact. In addition, the front passenger seat is equipped with Occupant Position Detection System (OPDS), an innovative technology designed to deactivate the side airbag if a child or small-stature adult leans into the deployment path of the side airbag. When the front passenger returns to an upright seating position, the side airbag reactivates so it can deploy to help protect the occupant in a side impact. The unique system utilizes sensors in the passenger seatback to determine the height and position of the occupant. The MDX’s side airbags have a 2-chamber design featuring a stiffer lower chamber to load the pelvis area earlier in the collision, along with a softer upper chamber to help reduce the likelihood of a rib injury.
Side Curtain Airbags
In a severe side impact or rollover, the MDX’s side curtain airbags deploy from roof-mounted modules to help provide head protection for front and outboard rear occupants. Side curtain airbags effectively cover the side window area from the front to rear seats in both vehicle rollover and side impact collisions. Tests show that the g forces acting upon an outboard occupant’s head are far lower with side curtain airbags.
FRONT SEAT BELTS WITH AUTOMATIC TENSIONING SYSTEM
The MDX front seat belts have an automatic tensioning system with load limiters to help protect the driver and front passenger in a collision. Research has shown that seat belts that are snugly secured around the occupants provide better protection; thus, in the first few milliseconds of a collision a tensioning system—powered by a small pyrotechnic device—automatically tightens the front seat belts.
If deceleration forces rise above a predetermined threshold, a load limiter releases a small length of seat belt webbing to reduce the pressure applied to the occupant. The load limiter system helps reduce the injuries that seat belts can cause in a severe high-speed collision. In addition, the driver’s seat belt has a dual-stage load limiter that provides a higher initial load, and then steps down to a lower load after a certain amount of the seat belt spools out. The dual-stage load limiter is specially designed to prevent too much forward movement of the driver, given the close proximity of the steering wheel.
All MDX seating positions feature 3-point seat belts, and adjustable shoulder belt height is available for front seat passengers. The rear center seat belt buckle stores in a recessed pocket when not in use.
LATCH (LOWER ANCHORS AND TETHERS FOR CHILDREN)
The 2012 MDX includes a LATCH (Lower Anchors and Tethers for Children) child-seat mounting system for the outboard rear seating positions. LATCH features built-in lower anchors and ready-to-use tether attachment points that allow compatible child safety seats to be installed without using the vehicle’s seat belt system. Additionally, the LATCH system simplifies child-seat installation when an owner installs a LATCH-compatible child seat. The rear seat center passenger position has upper tether anchors only.
ACTIVE FRONT HEAD RESTRAINTS
The MDX front seats are fitted with active front head restraints designed to help minimize the risk of neck injuries in the event of a rear impact. The head restraint system is mechanically linked to a lumbar plate located inside of the front seatback. In a rear impact, the occupant’s body pushes against the seatback, causing the head restraint to move forward and upwards in a carefully prescribed arc. This motion helps equalize the impact forces transmitted to the neck and spine during the collision. Effectively managing and dispersing this crash energy is critical to help minimize the potential for injuries.
VOLUNTARY SAFETY IMPROVEMENTS
As the popularity soared for light trucks (including pickups, crossover vehicles and SUVs) in the last decade, so did the risk of such large vehicles colliding head-on with smaller ones. In light of this risk, engineers of the Acura MDX designed a front structure that helps minimize the likelihood of over-ride or submarining in frontal collisions between vehicles of disparate size.
Pedestrian Safety
The Acura MDX makes pedestrian injury mitigation a high priority, and adopts several pedestrian-injury mitigation measures that United States law does not require. For example, the MDX hood frame and aluminum hood panel are designed to help protect pedestrians by deforming over a broad area to absorb collision energy. In addition, the hood hinges are designed to bend and the windshield wiper pivots feature a breakaway design to help mitigate the likelihood of injury in the event that a collision with a pedestrian should occur.
Dynamic Rollover
Another target that Acura designers felt strongly about was the MDX’s ability to withstand a rollover with the roof frame maintained, no fuel system damage, and no tailgate or tailgate door-opening damage. The use of a high-strength steel safety cage provides the stiffness that allows the MDX to better withstand rollover forces.
STANDARD VEHICLE STABILITY ASSIST™ (VSA®)
Standard equipment on the Acura MDX is Vehicle Stability Assist™ (VSA®), an Electronic Stability Control system that enhances controllability while the vehicle is accelerating, braking, cornering, or when the driver makes a sudden maneuver. The VSA® works in conjunction with the vehicle’s Drive-by-Wire™ throttle system and its 4-channel anti-lock braking system (ABS) to help the vehicle maintain the driver’s intended path of travel. VSA® functions by applying brake force to one or more wheels independently while also managing the throttle, ignition and fuel systems to reduce engine power output.
Vehicle Stability Assist™ constantly analyzes data from seven sensors that monitor wheel and vehicle speed, steering input, lateral G-forces and yaw rate— then compares the driver’s control inputs with the vehicle’s actual response. Whenever the vehicle’s actual response falls outside of a predetermined acceptable range, VSA® intervenes with corrective action. If VSA® detects an oversteer condition, the system may apply braking force to the outside front and rear wheels to counteract the unintended yawing effect. Or in the event of understeer, VSA® may apply braking to the inside rear wheel while reducing engine power to help return the car to its intended course.
Vehicle Stability Assist™ is calibrated to work in a nearly transparent manner, meaning that drivers may not even be aware of its operation. Therefore, to keep the driver informed, an indicator light flashes on the instrument panel anytime the system is enhancing vehicle stability. While the driver may deactivate the VSA® and traction-control functions via a switch on the instrument panel, ABS and Brake Assist remain fully operational at all times.
ADVANCED 4-CHANNEL ABS WITH ELECTRONIC BRAKE DISTRIBUTION
The 2012 Acura MDX is equipped with 4-wheel disc brakes and a sophisticated 4-channel/4-sensor anti-lock braking system. The system helps improve active safety by offering a firm brake-pedal feel and a short activation stroke, as well as Electronic Brake Distribution (EBD) circuitry that automatically proportions braking force between the front and rear wheels based on the vehicle’s weight distribution. EBD helps maximize braking effectiveness whether the MDX is transporting only the driver, or is fully loaded with passengers and luggage.
BRAKE ASSIST
Brake Assist, which utilizes some of the VSA® system components, recognizes emergency braking situations and assists the driver to apply maximum braking force to slow the vehicle more quickly. This important system is controlled by special computer logic that determines when the speed and stroke of the brake pedal exceed a typical range— as they would in a panic stop. At this point the modulator pump increases braking pressure to ensure maximum stopping force and help shorten braking distance. Brake Assist functions only when the driver is pressing the brake pedal, and the additional braking force provided by the system ceases when the driver releases pressure on the brake pedal.
COLLISION MITIGATING BRAKING SYSTEM™ (CMBS™)
The MDX Advance Package includes a Collision Mitigating Braking System™ (CMBS™), the first application of this technology on an Acura SUV. This revolutionary safety technology monitors the likelihood of a rear-end collision, and uses audio, visual and tactile signals to alert drivers to the risk of collision. Should the system determine that a collision likely is unavoidable, it applies the MDX’s brakes and tensions the front seat belts to help reduce impact force on occupants. Unlike pre-collision systems on competitive vehicles, in certain circumstances CMBS™ automatically applies the brakes to help mitigate the severity of a collision.
Using a millimeter-wave radar unit located inside the front grille, the CMBS™ system monitors the distance between the MDX and the vehicle directly in front of it up to a distance of 300 feet, and tracks the rate of closure between the two vehicles. If the closing rate increases to a point where a collision is likely to occur (based on relative vehicle speeds and following distance), CMBS™ uses visual and audible warnings to prompt the driver to take preventative action.
Based on the driver’s response, the system will disengage if it determines that the likelihood of a collision has decreased to an acceptable level. If the driver’s response does not sufficiently reduce the risk of a collision, CMBS™ will issue a secondary warning consisting of audible, visual and tactile elements as well as light braking to alert the driver to take action. If the closing rate increases so much that a collision becomes seemingly unavoidable, CMBS™ can initiate hard braking to reduce the vehicle’s speed as well as automatically tension the driver and front passenger seat belts to help reduce the severity of the crash. In some circumstance, CMBS will not give any or all warnings before applying the brakes.
The CMBS™ system used in the MDX’s Advance Package uses special seat belt retractors that replace the standard automatic tensioning system found on the base MDX and the MDX with Technology Package.
TIRE PRESSURE MONITORING SYSTEM (TPMS)
The Acura MDX has a Tire Pressure Monitoring System (TPMS) that alerts the driver whenever the air pressure in one or more of the tires decreases below a specified level. Using four sensors (one mounted in each tire), TPMS transmits information on tire air pressure to the vehicle’s ECU. A low tire pressure indicator located on the instrument panel illuminates when tire pressure drops to a potentially critical level.
FUEL TANK SAFETY
The MDX’s 21-gallon fuel tank is positioned in front of the rear body-deformation zone to minimize the risk of damage in a collision. Locating the fuel tank in this protected area optimizes vehicle balance by moving the weight of the fuel tank farther forward. Thus, handling characteristics are minimally affected whether the fuel tank is full or near empty.