In a method for carrying out bidirectional communications between a first electronic unit and a second electronic unit, a clock signal and an input signal synchronized with the clock signal are transmitted from the first electronic unit to the second electronic unit, and the second electronic unit transmits a response sequence in an output signal to the first electronic unit. In addition, an unambiguous test sequence is generated in the second electronic unit and transmitted to the first electronic unit prior to the response sequence in the output signal, a time sequence between the test sequence and the response sequence in the output signal making it possible to take into account a time delay between the first electronic unit and the second electronic unit.