DTC P0201-P0204: Injector Control Circuit: Description

WARNING: This page is about a different car, the 2002 Saturn LW200, 2002 Saturn L200, and 2002 Saturn L100. However, it is still accessible from the selected car via links, so may be relevant.

The fuel injection system utilizes sequential fuel injection. The PCM independently controls each fuel injector through separate internal drivers. The PCM drivers hold each fuel injector circuit to ground for a certain length of time based on engine operating parameters. The fuel control system is designed to maintain a 14.7 to 1 air/fuel ratio under all conditions except power enrichment mode (heavy acceleration/heavy engine load). The PCM calculates the current flow through each fuel injector by monitoring the voltage drop across a fixed internal resistor. The current through each driver rises to a peak of 4 amps then lowers to 1 amp to keep the injector open. This is called peak and hold. DTC P0201-P0204 sets when the PCM has detected that the injector cannot reach a calibrated peak amperage value when the fuel injector is commanded ON.