Circuit Description

PCM has 4 injector driver circuits controlling each injector. PCM monitors current at each injector driver circuit by measuring voltage drop through a fixed resistor and is able to control the driver circuit. Current through each driver can rise to a peak of 4 amps to quickly open the injectors and can drop to one amp to hold injectors open. This called the peak and hold. If current cannot reach a 4 amp peak, DTC will set. DTC will also set if an injector driver is shorted to voltage.

Injector circuit is continuously checked when engine is running.