DTC P0204: Injector No. 4 Control Circuit: Description

WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

The fuel injection system on 6 cylinder engines utilize sequential fuel injection. The ECM independently controls each fuel injector through separate internal drivers. The ECM drivers hold each fuel injector circuit to ground for a certain length of time based on engine operating parameters. When the injector driver is commanded off (circuit not grounded), the voltage level at the ECM should be high (ignition voltage). When the injector driver is commanded on (circuit grounded), the voltage level at the ECM should be low. The ECM injector driver feedback circuit uses a pull-up voltage (2.6-4.6 volts), which allows the ECM to individually differentiate between an open, short to ground or short to voltage. DTC P0204 will set if the ECM detects an open in fuel injector No. 4 control circuit when fuel injector No. 4 is commanded off with engine cranking/running.