Fiat 500 C Manual page 33

Diagnosis and recovery conditions.
In the following table, the signals exchanged between BCM and RCU are listed, concerning the
diagnosis strategies and the possible recovery strategies.
Diagnosis signals
Vehicle speed status failure
Outside temperature
failure
Roof position failure
Time_out failure*
Roof opening switch failure
Roof closing switch failure
H_Bridge failure**
Locked motor system
Motor system failure
Battery initialisation
voltage
* TIMe_OUT failure concerns the opening or closing button activation time. If either button is pressed
(locked) for a time longer than 60 seconds, the RCU prevents the soft top movement until the locked
button is released.
** H_BRIDGE belongs to the motor overvoltage protection system. It is mainly an additional circuit
inside the motor, that can take up the overvoltage and reduce motor overheating.
No communication on LIN line.
If the communication on LIN line disappears, the soft top cannot be moved anymore through the
interior buttons and the remote control. Under such conditions, the RCU cannot be woken up by the
interior buttons, as the key status (key on/off) is sent only by LIN. If the soft top is being moved and
the LIN line stops working, thus stops communicating, the soft top locks and it cannot be closed
anymore. The closing is possible only through emergency manoeuvres.
Description
It is set when the vehicle speed
signal is invalid.
status It is set when
temperature sensor sends an
invalid value to the BCM.
It is set when the RCU sends
BCM information
incorrect roof position.
It is set when the activation
switch is pressed for over 60
seconds
Malfunctioning opening interior
button
Malfunctioning
button
It is generated as a result of
absorption overcurrents,
heating, short circuit to Vbatt or
GND
It is set when the motor locks
suddenly
Motor in short
overheating
under It is set during the initialisation
procedure and a battery voltage
decrease is detected
Recovery strategies
The roof is not moved.
the outside The roof is not moved.
The roof is not moved.
about an
Soft
prevented until the button is
released.
The roof cannot be moved in
opening
closing interior The roof cannot be moved in
opening
The relevant error is reset once
over- the
current decreases.
Prevention for 30 seconds and
new control to be sent
circuit or Once the short circuit has been
removed, or the system has
cooled down, enter the control
again
Repeat
procedure.
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movement function
system cools down
the initialisation
Fiat 500 C – S&S
or