Circuit Description

PCM will enable an injector on the intake stroke of each cylinder. Individual cylinder fuel control is referred as Sequential Multiport Fuel Injection (SFI).

Ignition voltage is supplied directly to fuel injectors and PCM controls the ground circuit through an internal switch called the injector driver. Each driver has a fault line which is monitored by the PCM. When PCM is commanding a component ON, voltage on control circuit should be low (near zero volts). When PCM is commanding a component OFF, voltage on control circuit should be high (near battery voltage). If fault detection circuit senses a voltage other than what is expected, DTC will set.

PCM will monitor each injector circuit for the following: grounded circuit, open circuit, circuit shorted to voltage, open injector, shorted injector or injector with low resistance. When PCM detects any of these malfunctions, DTC P0200 or P1222 will set, and the affected injector driver will be disabled.