Mercedes-Benz 2002 SLK 320 - Manual (Page 56)

53 Restraint systems
Technical
data
Instruments
and controls
Operation Driving
Instrument
cluster display
Practical hints Car care Index
Emergency tensioning retractor (ETR)
The seat belts 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 and rear 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.
In cases of other frontal impacts, roll-overs, certain side
impacts, rear collisions or other accidents without
sufficient frontal or rear impact forces, the emergency
tensioning retractors will not be activated. The driver
and passenger will then be protected by the fastened
seat belts and inertia reel in the usual manner.
For seat belt and emergency tensioning retractor safety
guidelines see page 61.
Note:
The passenger ETR activates only if the passenger seat
is occupied.
Heavy objects on the 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 treshhold.