A method of operating a transceiver for imparting a voltage signal on a differential signaling bus, wherein the transceiver comprises an output terminal and a string of one or more transistors (301 - 306) connected between the output terminal and a predetermined voltage level, and wherein the transceiver can be switched between an active state in which the predetermined voltage level is applied to the output terminal, and an inactive state in which the predetermined voltage level is not applied to the output terminal, the method comprising: a detection step of continuously detecting a first quantity depending on a current flowing through a first transistor in the string of transistors (301 - 306); a failure determination step of determining whether the detected first quantity satisfies one or more error conditions; and a control step of switching the transceiver to the inactive state if the detected first quantity is determined to satisfy at least one of the one or more error conditions, wherein the detection step involves detecting a second quantity indicative of a current flowing through the first transistor in a first direction; and the failure determination step involves: comparing the detected second quantity to a first threshold; and determining that the first quantity satisfies an error condition if the detected second quantity exceeds the first threshold, and characterized in that the detection step further involves detecting a third quantity indicative of a current flowing through the first transistor in a second direction opposite to the first direction; and the failure determination step further involves: comparing the detected third quantity to a second threshold; and determining that the first quantity satisfies an error condition if the detected third quantity exceeds the second threshold. a detection step of continuously detecting a first quantity depending on a current flowing through a first transistor in the string of transistors (301 - 306); a failure determination step of determining whether the detected first quantity satisfies one or more error conditions; and a control step of switching the transceiver to the inactive state if the detected first quantity is determined to satisfy at least one of the one or more error conditions, wherein the detection step involves detecting a second quantity indicative of a current flowing through the first transistor in a first direction; and the failure determination step involves: comparing the detected second quantity to a first threshold; and determining that the first quantity satisfies an error condition if the detected second quantity exceeds the first threshold, and characterized in that the detection step further involves detecting a third quantity indicative of a current flowing through the first transistor in a second direction opposite to the first direction; and the failure determination step further involves: comparing the detected third quantity to a second threshold; and determining that the first quantity satisfies an error condition if the detected third quantity exceeds the second threshold. comparing the detected second quantity to a first threshold; and determining that the first quantity satisfies an error condition if the detected second quantity exceeds the first threshold, and characterized in that the detection step further involves detecting a third quantity indicative of a current flowing through the first transistor in a second direction opposite to the first direction; and the failure determination step further involves: comparing the detected third quantity to a second threshold; and determining that the first quantity satisfies an error condition if the detected third quantity exceeds the second threshold. comparing the detected third quantity to a second threshold; and determining that the first quantity satisfies an error condition if the detected third quantity exceeds the second threshold.