Patent ID: 9587610
Date: 2017-03-07
CPC Classifications: F02D,F02M

Claim:
1. A method for operating a fuel injection system of an internal combustion engine, the method comprising: testing a piezo injector during a switch-on test routine, a switch-off test routine, or an overrun phase of the internal combustion engine, the test including: injecting fuel during an injection cycle that includes a charging phase, a holding phase, and a discharging phase, determining a leakage resistance of the piezo injector based on characteristics of the piezo injector measured during the holding phase, comparing the determined leakage resistance to a predetermined threshold, and switching off injection by the piezo injector during normal operation of the internal combustion engine if the determined leakage resistance is less than the predetermined threshold and providing an indication that the piezo injector should be replaced.