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TRW 'Firsts' Pave Way for Next Generation of Air Bag Disable Switches

17 February 1998

TRW 'Firsts' Pave Way for Next Generation of Air Bag Disable Switches

    DETROIT, Feb. 17 -- What does a company do after it has
scored three industry "firsts" in air bag disable switch technology?  When
that company is TRW, it accelerates development to keep its products well
ahead of the pack.
    That's why TRW Automotive Electronics Group -- which developed and
produced the first passenger air bag disable (PAD) switch, the first retrofit
passenger air bag disable switch and the first intelligent PAD switch -- is
focusing its expertise and experience on creating next-generation switches
offering even greater value and function.  The TRW firsts will be displayed at
the 1998 SAE International Congress & Exposition at Detroit's Cobo Center next
week.
    In 1995, TRW began production of the industry's first passenger air bag
disable switch, enabling light truck drivers to disarm the passenger air bag
when a rear-facing infant seat or small child was present in the front seat.
Last year, TRW introduced the first retrofit air bag disable (RAD) switch for
automakers -- offering driver and passenger side application in response to
the recent National Highway Traffic Safety Administration ruling on air bag
deactivation.
    The first intelligent passenger air bag disable (IPAD) switch -- which TRW
put into production in 1997 for the 1998 model year -- offers higher
reliability, a 30-percent parts count reduction, greater packaging flexibility
and cost-savings potential over its predecessor.
    Designed to work with a vehicle's air bag diagnostic module or body
controller, the TRW IPAD is constantly polled by the electronics to determine
switch position.  If the switch is in the "OFF" position and a crash occurs,
the air bag controller would prevent the passenger air bag from deploying.
    To operate the switch, the driver simply inserts the ignition key into a
lock cylinder on the instrument panel, turns it clockwise 45 degrees to the
detent position and removes the key.  An indicator lamp showing the word "OFF"
confirms that the passenger air bag has been disabled, and the air bag remains
disabled until the switch is rotated back to its original position with the
ignition key.
    Tested to 15,000 cycles and proven in sled tests and actual vehicle crash
tests, TRW's IPAD switch uses a hermetically sealed contact system to protect
the switch from environmental contamination.  The TRW IPAD switch has been
impact-tested to 50 Gs of force on all axes and operates throughout a
temperature range of -40o C to 85o C.
    Since the TRW IPAD switch interfaces with the air bag diagnostic module,
switch contact bounce can be filtered out to reduce impact sensitivity.  The
module's diagnostics also monitor the switch's indicator light, allowing for a
standard lamp to be used instead of a more expensive, high-intensity light
emitting diode (LED).  Because the module also records the state of the switch
at the time of impact, the telltale fuse used in the first generation PAD
switch has been eliminated.
    According to Ronald Muckley, vice president of product engineering, North
America, TRW Automotive Electronics Group, work is well underway on TRW air
bag disable switch designs which will meet automakers' evolving system
architectures, as well as the potential needs for both driver and passenger
side applications.
    "As development partners, we can ensure that our next-generation switches
provide automakers with a whole new level of benefits, in terms of system
integration, packaging, reliability, flexibility and cost-effectiveness," said
Muckley.  "By leveraging our unsurpassed safety electronics experience, our
complete safety system expertise and our modular approach, we can help our
customers reduce critical development time."
    TRW currently provides original equipment air bag disable switches for
various 1998 model year vehicles, including the Ford F series truck, Dodge
Dakota truck, Dodge Ram pickup, Dodge Ram van and Plymouth Prowler.  TRW also
supplies eight versions of a retrofit air bag disable switch to cover 111
General Motors platforms.
    TRW Automotive Electronics Group is a leading producer of electronic
safety, security and convenience systems for the global automotive market.  In
addition to air bag disable switches, its major product lines include air bag
crash sensors, occupant sensing systems, remote keyless entry systems, switch
and control systems, advanced theft-deterrent and security systems, driver
information systems, body controllers and electrically assisted steering
control units, as well as engineered fastening systems.
    With 122 automotive locations in 23 countries, TRW Inc. is one
of the largest independent OEM automotive suppliers in the world.  In 1997,
the company's automotive businesses recorded sales of $7 billion, nearly
65 percent of TRW's total $10.8 billion in sales.  Based in Cleveland, Ohio,
TRW also provides advanced technology products and services for space and
defense, and information technology markets worldwide.

SOURCE  TRW Inc.