A touchscreen resistive sensor includes a network of resistive sensor branches coupled to a number of sensor nodes arranged at touch locations of the touchscreen. A test sequence is performed by sequentially applying to each sensor node a reference voltage level, jointly coupling to a common line the other nodes, sensing a voltage value at the common line, and declaring a short circuit condition as a result of the voltage value sensed at the common line reaching a short circuit threshold. A current value level flowing at the sensor node to which the reference voltage level is applied is sensed and a malfunction of the resistive sensor branch coupled with the sensor node to which a reference voltage level is applied is generated as a result of the current value sensed at the sensor node reaching an upper threshold or lower threshold.