Lexus GS300 1998 Owner's Manual page 153

COMFORT ADJUSTMENT
16G023
The driver and front passenger airbags and seat belt
pretensioners are designed to activate in response to a
severe frontal impact within the shaded area between the
arrows in the illustration.
There may be the case that the driver and passenger airbags
and seat belt pretensioners will not activate with such an
impact in which the occupant wearing the seat belt correctly
would not get serious injury.
The driver and front passenger airbags and seat belt
pretensioners will work if the severity of the impact is above
the designed threshold level, comparable to an approximate
24 km/h (15 mph) collision in the U.S.A. and 30 km (18 mph)
collision in Canada when impacting straight into a fixed
barrier that does not move or deform.
If the severity of the impact is below the above threshold
level, the driver and front passenger airbags and seat belt
pretensioners may not work.
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However, this threshold velocity will be considerably higher
if the vehicle strikes an object, such as a parked vehicle or sign
pole, which can move or deform on impact, or if it is involved
in an underride collision (e.g. a collision in which the nose of
the vehicle "underrides", or goes under, the bed of a truck).
It is possible with collision severity at the marginal level of
driver and passenger airbag sensor detection and activation
that only one of your vehicle's driver and front passenger
airbags and seat belt pretensioners will work.
For the safety of all occupants, be sure to always wear seat
belts.