Abstract: Methods for monitoring a motor vehicle electrical system. At least one power distributor is provided, via which at least one safety-relevant consumer is supplied with a supply voltage and via which non-safety-relevant consumers are supplied. The power distributor is supplied by at least one stored energy source. A measure for the voltage applied at least to the safety-relevant consumer is ascertained, wherein, on that basis, an undervoltage at the safety-relevant consumer is ascertained in dependence on a limit value. A reduction measure for a disconnection or downgrading of at least one non-safety-relevant consumer required to increase the voltage applied to the safety-relevant consumer is determined in dependence on the undervoltage, and a selection of the non-safety-relevant consumer to be disconnected or to be downgraded is made based on the reduction measure.

Abstract: A method for monitoring an on-board power supply of a motor vehicle. A power distributor is provided, via which a supply voltage is supplied to a safety-relevant consumer and via which non-safety-relevant consumers are supplied. A disconnection of consumers takes place if at least one measure of the voltage applied at least to the safety-relevant consumer reaches a limit value. After disconnecting consumers, the measure of the voltage applied to the safety-relevant consumer is ascertained. The measure of the voltage applied to the respective safety-relevant consumer is respectively compared to a further limit value for a sufficient voltage. From the disconnected consumers, at least one consumer to be connected is selected, which is connected if the limit value is respectively reached at the safety-relevant consumers. The consumer to be connected is selected as a function of a connection measure such that the connection measure is not exceeded.

Abstract: A method for monitoring an electrical system of a motor vehicle. A safety-related electrical consumer and possibly further electrical consumers are supplied by an energy accumulator. At least one model of the vehicle electrical system is provided which represents the safety-related electrical consumer and corresponding lines with associated line resistances and connection to the energy accumulator.

Abstract: A method for monitoring an on-board power supply of a motor vehicle. A power distributor is provided, via which a supply voltage is supplied to a safety-relevant consumer and via which non-safety-relevant consumers are supplied. A disconnection of consumers takes place if at least one measure of the voltage applied at least to the safety-relevant consumer reaches a limit value. After disconnecting consumers, the measure of the voltage applied to the safety-relevant consumer is ascertained. The measure of the voltage applied to the respective safety-relevant consumer is respectively compared to a further limit value for a sufficient voltage. From the disconnected consumers, at least one consumer to be connected is selected, which is connected if the limit value is respectively reached at the safety-relevant consumers. The consumer to be connected is selected as a function of a connection measure such that the connection measure is not exceeded.

Abstract: A method for monitoring an electrical system of a motor vehicle. A safety-related electrical consumer and possibly further electrical consumers are supplied by an energy accumulator. At least one model of the vehicle electrical system is provided which represents the safety-related electrical consumer and corresponding lines with associated line resistances and connection to the energy accumulator.