A client computing system (CCS) receives a download including (i) an image representative of at least one circuit in a vehicle, the at least one circuit including a first circuit configured for carrying a first signal within the vehicle, and (ii) symbol data associated with at least one symbol, the at least one symbol including a first symbol. After receiving the download, the CCS displays the image and the at least one symbol. The CCS then receives a first input corresponding to selection of the first symbol. The CCS then responsively receives, from the vehicle, data representing value(s) of the first signal. The CCS then determines a first display-location at which to display the data representing the value(s) of the first signal. While the image and the at least one symbol are displayed, the CCS then displays, at the first display-location, the data representing the value(s) of the first signal.