The electronics installed in the FCTO continuously checks the satisfactory operation of the unit for:
Voltage interruptions
Malfunctions in the pulse generator system
Voltage interruption
Voltage interruptions, such as disconnecting the battery are recorded by the electronics.
If the voltage is restored, the ignition is switched on and the driver's tachograph chart is inserted, the vehicle speed indicator deflects to the final value on the scale 15 times within two minutes. The pointer then returns to the zero position.
Malfunctions in the pulse generator system
When the ignition is switched on and the driver's tachograph chart is inserted, malfunctions of this type are either displayed only when the vehicle is stationary (while driving a normal vehicle speed continues to be displayed) or while driving and when the vehicle is stationary by rhythmic deflections of the vehicle speed indicator between 0 and 30 km/h.
The pointer deflects in an 8 second cycle.