DTC P0201: Injector No. 1 Control Circuit: Description

ECM independently controls each fuel injector through separate internal drivers. ECM drivers hold each fuel injector circuit to ground for a certain length of time based on engine operating parameters. When injector driver is commanded off (circuit not grounded), voltage level at ECM should be high (ignition voltage). When injector driver is commanded on (circuit grounded), voltage level at ECM should be low. ECM injector driver feedback circuit uses a pull-up voltage (2.6-4.6 volts), which allows ECM to individually differentiate between an open, short to ground or short to voltage. DTC sets when ECM detects an open injector driver control circuit when injector is commanded off with engine cranking/running.