C 300 (204.054) V6-3.0L (272.947) (2008)
General
The vehicle remote door unlock function enables the customer to have his/her vehicle remotely unlocked when he/she, e.g. has lost the transmitter key
(A8/1) and a 2nd transmitter key is not available.
Vehicle remote door unlock function sequence
Actuation of the trunk lid external operation switch is received by the emergency call system control unit in the following way:
^
Discrete line
^
Rear SAM control unit with fuse and relay module (N10/2)
^
Interior CAN
^
Front SAM control unit with fuse and relay module (N10/1)
^
Diagnostic CAN
The emergency call system control unit then automatically transmits an SMS with the following data to the CAC via the communication module
integrated into the emergency call system control unit:
^
Chassis number
^
Vehicle model
A voice connection to the CAC is also set up via the communication module integrated into the emergency call system control unit. The communication
module integrated into the emergency call system control unit transmits the mobile phone signals or data in the following way:
^
Discrete line
^
Frequency switchover control unit (N96), with code (389) Mobile phone preinstallation with universal interface, USA/ Canada
^
Discrete line
^
Multifunction antenna (A28/11)
The CAC compares the sent data with the query and customer legitimization and if the data matches up a "vehicle remote door unlock request" is sent to
the vehicle.
The communication module integrated into the emergency call system control unit receives the "vehicle remote door unlock request" and the mobile
phone signals or data in the following way:
^
Multifunction antenna
^
Discrete line
^
Frequency switchover control unit, with code (389) Mobile phone preinstallation with universal interface, USA/Canada
^
Discrete line
After receiving the "vehicle remote door unlock request", the emergency call system control unit sends the request in the following way to the electronic
ignition lock control unit (N73):
^
Diagnostic CAN
^
Front SAM control unit with fuse and relay module
^
Interior CAN
The EIS [EZS] control unit then initiates the unlocking of all vehicle doors and the unlocking of the trunk lid.
If the "vehicle remote door unlock request" from the CAC is rejected, then the vehicle remote door unlock function is blocked for t = 15 min.
The execution of the vehicle remote door unlock is displayed by a message in the instrument cluster (A1).
In the event of a vehicle remote door unlock, any other vehicle-related services (e.g. vehicle remote locking) and, for vehicles with code (389) Mobile
phone preinstallation with universal interface, USA/Canada, active mobile phone connections are interrupted.
In the event of a multifunction antenna malfunction (e.g. defective because of rollover) the emergency call system control unit automatically uses the
emergency call system antenna (A2/52) to transmit mobile phone signals or data.