Patent ID: 8232887

Claim:
A process for electronic monitoring of an on-board power supply system, or parts of the on-board power supply system, of a motor vehicle with respect to voltage peaks or voltage drops, the process comprising the acts of: recording continuously, during normal operating conditions, electric voltage values of a primary and/or secondary side of an ignition voltage circuit of the motor vehicle after reducing a measuring voltage by way of a voltage divider; comparing an earlier recorded voltage value with a subsequently recorded second voltage value using a comparator circuit; maintaining, in the comparator circuit and for up to a predetermined time period, a highest voltage value and a time stamp of said highest voltage value, of the continuously-recorded electric voltage values, recorded up to that point-in-time; and determining whether a fault occurred in one of the on-board power supply system and a control unit operatively coupled to the on-board power supply system; and in response to determining that a fault occurred, recording from the comparator circuit into a fault memory, the then-highest voltage value being maintained by the comparator circuit, together with a description of the fault.