The fault detection device is used for a load (1) supplied with current via a high- side power switch (3) and a low-side power switch (4), supplied with control signals from a control device (2), with a measuring device (5) connected in parallel with the load switches and the series load. The measuring device provides a diagnosis voltage (Vdiag) for a diagnosis device (6),detecting faults within the load circuit by comparison with a reference voltage (Vref), for supplying a corresponding fault signal to a display.
