Emergency Tensioning Retractor (Etr) - Mercedes-Benz 2002 M-Class Operator's Manual

Emergency tensioning retractor (ETR)

The seat belts for the outboard passenger seats (except
in the optional 3rd row 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 impacts exceeding the first threshold of the SRS
and in rear impacts exceeding a preset severity level.
They remove 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.
Restraint systems
Instruments
Operation
and controls
Instrument
Driving
cluster display
In cases of other frontal impacts, angled impacts, roll-
overs, certain side impacts, or other accidents without
sufficient frontal or rear impact 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 tensioning retractor see
page 66.
Note:
The front passenger ETR activates only if the front
passenger seat is occupied.
Heavy objects on the front passenger seat can appear to
the "SRS" to indicate the presence of an occupant in
that seat which causes the passenger front airbag to
deploy and the ETR to activate in a crash exceeding the
appropriate threshold.
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