DTC P0200: Injector Control Circuit: Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2001 Saturn SW2, 2001 Saturn SL2, 2001 Saturn SL1, 2001 Saturn SL, and 2001 Saturn SC2. However, it is still accessible from the selected car via links, so may be relevant.
The injector system on both the DOHC and SOHC engines utilize Sequential Fuel Injection (SFI). The PCM independently controls each fuel injector through a driver circuit, in accordance with intake valve opening. The driver circuit is internally located in the PCM, providing the ground for each injector. The length and time an injector is held open (grounded by PCM) is calculated based on engine speed, load and valve location from the crankshaft position sensor. DTC is used when PCM cannot distinguish which injector circuit has failed or type of fault that occurred (open, short to ground or short to voltage) with circuit because length of time condition existed was to short.