With a diagnostic computer (OBD reader), one can read fault codes and live data. In the event of a fault, it may be necessary to carry out a measurement. With a multimeter or oscilloscope, electrical components and systems in a vehicle can be measured. In the case of faults, the measurement results can provide clarity about defective components or wiring. To perform measurements, one must be able to locate the correct wire. Therefore, it is often necessary to consult a wiring diagram. The diagram shows, among other things, wire colours and thicknesses between a control unit, a sensor or actuator. If a breakout box is available, time can be saved because the measurement connections are easily accessible.
