A method for testing a signal path of a first IC formed as a monolithically integrated circuit on a semiconductor body together with a magnetic field sensor and has a signal output and a power supply connection and a test mode state and a normal operating state. A power supply of the first IC is switched off, and a signal output is connected with a reference potential, and the power supply of the first IC is switched on and the signal output is disconnected from the reference potential. Subsequently in a test mode state, a self-test is performed in the first IC and a test pattern is configured at the signal output or at the power supply connection and the test pattern is evaluated by the control unit for testing of the signal path.