Mercedes-Benz 2006 C 55 AMG Operator's Manual page 237

Controls in detail
Audio system
The following conditions must be met for a
"911" emergency call:
Telephone must be switched on.
The corresponding mobile communica-
tions network must be available.
i
Emergency calls may not be possible
with all telephone networks or if certain
network services and/or telephone
functions are active. Check with your
local service providers.
If you cannot make an emergency call, you
will have to initiate rescue measures
yourself.
236
GSM network phones
Placing a "911" emergency call using
audio head unit with the phone locked
Press h button to switch to
telephone operation.
PIN? appears in the audio display.
Enter 911 using the number keypad on
the audio head unit.
soft key or s button for
Press OK
dialing to begin.
DIALING appears in the audio display
while the telephone establishes the
connection.
Wait until the emergency call center
answers, then describe the emergency.
Placing a "911" emergency call using
audio head unit with the phone
unlocked
Press h button to switch to
telephone operation.
Enter 911 using the number keypad on
the audio head unit.
Press s button for dialing to begin.
DIALING appears in the audio display
while the telephone establishes the
connection.
Wait until the emergency call center
answers, then describe the emergency.
i
If no SIM card is in the mobile phone,
NO SERVICE appears in the audio
display. In that case, you only can make
an emergency call on the mobile phone
itself, without the use of the head unit.