Mercedes-Benz 450 SL 1980, Owner'S Manual

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Master Lock System
The master lock system enables the
front passenger door, the fuel tank
fille r flap and the trunk lid to
be locked or unlocked together
with the d river’s door. When locking
or unlocking, the locking levers
on both doors must move sim ul­
taneously. If one locking lever fails
to do so, the lock of that p articular
door is not properly engaged.
The door must then be opened and
closed correctly.
With the master lock system in the
locked position, the fro n t passenger
door can be locked and unlocked
either with the locking lever or
with the key.
Actuation of the locking lever on
the front passenger door, however,
is not possible when the master
lock system is in the unlocked
position.
The trunk lid can also be unlocked
separately by turning master key
counterclockw ise to the stop. Push
the trun k lock button in with it and
lift the lid. Return the key to its
initial position and w ithdraw it. To
lock the lid, close it firm ly. It w ill
then be locked again by the master
lock system.
A provision has been made to
fa cilita te perm anent locking of the
trunk lid fo r positive prevention
of access to trunk by unauthorized
persons.
Before leaving vehicle with an
attendant, lock tru n k w ith master
key (square head) by turning key
clockw ise to stop (tum bler slot
vertical), then provide attendant
with round-headed supplem entary
key. Thus, the trunk lock has been
excluded from the operation of the
master lock system and cannot be
opened except with the square­
headed m aster key.
Keys Doors
To reverse this, turn trun k lock
counterclockw ise back to hori­
zontal position of the tum bler
slot w ith m aster key. Lock w ill then
be reengaged in m aster lock
system; that is, it w ill autom atically
be locked or unlocked depending
on whether the d river’s door
is locked or unlocked.
The m aster lock system operates
on vacuum generated bythe en g in e.
A reservoir allows the master lock
system to be actuated about five
tim es after the engine is turned off.
If the system can then no longer be
engaged, idle engine fo r a short
period.
If no vacuum is available, doors and
trunk have to be locked individually
in the normal manner. The fuel
tank fille r flap, however, remains
unlocked.
Note:
If the fille r flap cannot be opened
when the m aster lock system is
unlocked, refer to "U nlocking of the
F iller Flap” (page 64).
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