MTU 12 V 2000 P12 Operating Instructions Manual page 32

Fault messages are stored in two memories:
• Chronological memory
The fault message numbers are stored in a ring memory in chronological order of their occurrence or
cancellation together with the hour meter reading. The ring memory stores the last 80 setting and can‐
cellation procedures.
• Statistical memory
Fault message occurrences are counted in a statistical memory.
A counter counting up to max. 10 000 is set up for each fault message number .
Monitoring of engine governor electronics
The hardware and software of the engine governor is designed to allow faults in the electronic system to
be detected to enable the operator to respond accordingly to such faults. Fault signals are also forward‐
ed.
The temperature inside the engine governor housing is monitored. Should it rise above a limit value, a
fault signal is output via the combined alarm output and the CAN bus to a higher-level monitoring system
(if applicable) where it can be visualized for the operator.
Monitoring of sensors and actuators
The various sensor and actuator channels of the engine governor system are designed to tolerate faults
to a large extent (e.g. short-circuit withstandability).
Faults such as broken wires, short circuit etc. are detected by plausibility checking and are output to a
higher-level monitoring system (if applicable) in the form of a combined alarm.
Monitoring of bus communication
Bus communication is monitored by plausibility checking and timeout monitoring. Detected faults are out‐
put in the form of a combined alarm and, if possible, to a higher-level monitoring system (if applicable)
via the CAN bus.
Overspeed test
Activating this input lowers the overspeed threshold such that the engine shuts down at any speed. This
makes it possible to check that the overspeed shutdown function operates correctly.
32 | General Information | MS150025/02E 2012-10