Mercedes-Benz 600 SEL Automobile User Manual


 
49
Supplemental Restraint System
(SRS)
The SRS uses two crash severity levels
(thresholds) to activate either the ETR
or airbag or both. Activation depends
on exceeding the thresholds and
fastening of the seat belt.
Seat belt fastened
first threshold exceeded:
ETR activates
second threshold exceeded:
airbag also activates
Seat belt not fastened
first threshold exceeded:
airbag activates, but not ETR
Driver and front passenger systems
operate independently from each other.
Emergency Tensioning
Retractor (ETR)
The seat belts for the front seats are
equipped with emergency tensioning
retractors. These tensioning retractors
are located in each belt's inertia reel
and become operationally ready with
the key in steering lock position 1 or 2.
The emergency tensioning retractors
are designed to activate only when the
seat belts are fastened during frontal
and front-angled impacts exceeding the
first threshold of the SRS. They re-
move slack from the belts in such a
way that the seat belts fit more snugly
against the body restricting its forward
movement as much as possible.
In cases of other frontal impacts,
roll-overs, certain side impacts, rear
collisions, or other accidents without
frontal forces, the emergency
tensioning retractors will not be
activated. The driver and passengers
will then be protected by the fastened
seat belts and inertia reel in the usual
manner.
For seat belt and emergency ten-
sioning retractor safety guidelines see
Safety Guidelines in Index.