The Variable Torque Management (VTM-4) all-wheel-drive system is the key to
sure-footed handling and straightforward controllability whether the pavement is
dry or wet and slippery. Combined with MDX's new Vehicle Stability Assist (VSA),
4-wheel independent suspension, torque sensing power rack-and-pinion steering,
and four-wheel-disc brakes with ABS, VTM-4 delivers best-in-class traction to
enhance the driver's ability to guide an MDX safely out of harm's way.
To help safeguard occupants from injury when a collision is unavoidable, MDX
provides multiple layers of protection. The computer-engineered body structure
features front, side and rear crumple zones to help protect occupants during
offset and side impacts, and a well protected fuel tank. Extensive use of
high-strength steel yields a robust safety cage surrounding passengers without
incurring an awkwardly heavy curb weight.
All seating positions have three-point seat belts. Front seat belts are equipped
with pretensioners and automatic load limiters that are activated in certain
collision conditions. The MDX comes with standard front dual stage, dual
threshold front air bags. These air bags can deploy at the most appropriate of
two rates depending on the severity of the crash. In addition, if the driver's
or passenger's seat belt is not fastened, the air bag deploys at a lower
collision speed to help offer more protection to the unbelted occupant.
For 2003, the MDX adds two weight sensors to the front passenger's seat and a
driver's seat position sensor to the dual-stage, dual-threshold front airbag
system.
The driver's and front passenger's seats also feature side air bags mounted in
the seat bolster closest to the door. The passenger's seat is equipped with a
system designed to disable side air bag deployment and prevent injury to a small
child (or small-statured adult) if they lean into the side air bag deployment
path. Once the child returns to an upright seating position, the side air bag
will reactivate so it can deploy and protect the child in a side impact.
SAFETY STRUCTURE
MDX engineers used powerful computers to assure that this vehicle's safety cage
structural design would perform well even before physical prototypes were built.
Crash simulations helped reveal areas of the design that needed more - and
sometimes less - reinforcement to absorb energy while resisting intrusion.
MDX has an especially robust floor construction to optimize both rigidity and
resiliency. Two longitudinal rails run continuously from bumper to bumper. The
rails are buttressed by a total of eight box-section crossmembers and two bumper
bulkheads. This provides the strength needed to resist standard barrier impacts
at the front and rear, offset crashes (wherein most of the load is applied
longitudinally to one corner of the vehicle), and side impacts.
A four-ring shell-type safety cage is used to help protect occupants with A, B,
C, and D pillars that run continuously to avoid intrusion during side impacts.
To meet current federal head-impact requirements, roof-pillar trim and headliner
materials absorb energy and help reduce the likelihood of occupant head injury.
Stiffeners inside the doors at the beltline provide a continuous horizontal
connection between the first three pillars. Tubular beams are welded inside the
doors at wheel height to provide additional intrusion resistance.
One quarter of the body structure - longitudinal rails, floor crossmembers,
pillar reinforcements, and bumper beams - is made of high-tensile steel for
maximum strength with minimal weight.
MDX's fuel tank is made of highly puncture resistant, six-layer, high-density
molded-polyethylene, with high-strength, box-section floor reinforcements to
help guard it from side collision damage. It is located ahead of the rear axle
for protection
The bottom line is best-in-class collision performance. Based on internal
simulation and testing, the MDX is expected to earn five stars in federal
government New Car Assessment Program (NCAP) frontal barrier tests and Side
Impact (SINCAP) tests. The MDX also received a "good" rating and a "best pick"
designation based on results from the Insurance Institute for Highway Safety's
40 mph frontal offset barrier tests.
FRONTAL RESTRAINT SYSTEMS
Unlike some SUVs, MDX provides a three-point restraint system for all seating
positions. A special roof-mounted reinforcement, positioned between the C and D
pillars, serves as a rigid mounting point for the second row, middle passenger's
shoulder belt.
Front seat belts are equipped with pretensioners and automatic load limiters
that are activated in conjunction with the front air bags.
DUAL-STAGE, DUAL-THRESHOLD FRONT AIRBAGS
The 2003 MDX is equipped with dual-stage, dual-threshold airbags for the driver
and front passenger. These airbags are designed to minimize the potential for
airbag injury while providing head and chest protection for the occupants in the
event of a collision. For 2003, this front airbag system features additional
sensors; front passenger seat weight sensors and a driver seat position sensor
designed to enhance occupant protection.
The MDX's front airbags can deploy at one of two rates. Deployment of the
driver's side airbag takes into account the severity of the crash, whether or
not the driver's seat belt is fastened and, new for 2003, the position of the
driver's seat. During a lower speed collision, the airbag inflators are
triggered in sequence, resulting in slower overall airbag deployment with less
initial force. The same sequence is also utilized regardless of collision speed
if the driver's seat is within a half inch of the full forward position. During
a higher speed collision if the driver's seat is more than a half inch from the
full frontal position, both inflators operate simultaneously for full, immediate
inflation. Airbag deployment on the front passenger's side is regulated by crash
severity, seatbelt usage and, for 2003, the weight of the occupant. Sensors
under the seat gauge occupant weight and if the total weight on the passenger
seat is less than 65 lbs, the airbag system will not deploy, minimizing the
potential for injury to children. During a lower speed collision, the airbag
inflators are triggered in sequence, resulting in slower overall airbag
deployment with less initial force. During a higher speed collision, both
inflators operate simultaneously for full, immediate inflation.
The driver's airbag is located in the steering wheel hub and the passenger's
airbag is located on top of the dash. As in all Acura automobiles, the front
passenger's airbag is designed to deploy upward toward the windshield and then
back toward the occupant. This provides a large cushion to help protect the
front passenger.
SIDE AIR BAG SYSTEM
Like other Acura models, MDX is equipped with seat-mounted side air bags to help
safeguard the driver and front passenger from side-impact injury. An innovative
occupant position detection system is used to assure that the passenger's side
air bag has a clear path for deployment. In the event a child (or a
small-statured adult) leans into the deployment path of the side air bag, a
seven-segment antenna system built within the backrest signals this condition to
an electronic control unit (ECU) also located within the seat. The ECU then
deactivates the side air bag from functioning and triggers a "SIDE AIRBAG OFF"
indicator light in the instrument cluster. After the front occupant returns to a
normal seating position, the side air bag module automatically resumes
full-functional status.
ANTI-THEFT ALARM SYSTEM
MDX has a standard keyless-remote entry system that locks and unlocks all doors
and the rear hatch at the push of a button. To enhance theft protection, only
one key lock mechanism is provided for the driver's door position. The same key
fob used to lock the doors also activates the MDX's security system. In response
to any attempt to enter the vehicle without the key fob or ignition key, the
horn sounds, and the flasher lamps are activated. If need be, the alarm system
can be triggered to summon help by depressing a "panic" button on the
remote-keyless fob.
SECURITY/IMMOBILIZER SYSTEM
Imbedded within MDX's ignition key is an electronic microprocessor circuit that
communicates with a receiver in the ignition switch to enable the vehicle's
electrical systems. Forcibly vandalizing the ignition switch, hot-wiring, or
attempting to start the car with a key lacking the microprocessor circuit will
result in immobilization. Without proper key-to-immobilizer communication, the
MDX will simply not start.
LOWER ANCHORS AND TETHERS FOR CHILDREN (LATCH) SYSTEM
The Lower Anchors and Tethers for Children (LATCH) system is standard on the
second row of outboard seats. The LATCH system features built-in, ready-to-use
anchors and tethers allowing compatible child safety seats to be installed
without using the vehicle's seat belt system.
