Erasable conductive domain walls (DWs) in insulating ferroelectrics are key components to reconfigurable nanocircuitries, nanosensors, and memories, but the wall currents are found to decay with time, especially at high temperatures. In this study, DW currents are induced upon partial domain switching against the peripheral unswitched bulk domain under the application of inplane electric field between two top electrodes patterned on epitaxial BiFeO3 (BFO) thin films. The “on” currents are followed by a drop at higher bias above the coercive voltage, which becomes more significant at elevated temperature from 298 to 408 K. An opposite “on” current is observed in the back sweeping when the above walls are erased to restore the as-grown, stable domain structure. The phenomenon is explained by a film defect-related model that free charges are injected and locally trapped at the defect levels to help screen the uncompensated polarizations in the conducting DWs, resulting in the wall current reduction. Once the walls are erased at opposite coercive voltages, the trapped free charges at the conducting DWs are expelled to form a discharge current. This finding provides the fundamental physics of the wall conduction in correlation with the film defects and reversible charge injection.