Circuit Description

ECM will enable an injector on intake stroke of each cylinder. Ignition voltage is supplied directly to fuel injectors. ECM controls each injector by grounding control circuit via an internal driver.

Primary function of driver is to supply ground for component being controlled. Each driver has a fault line which is monitored by ECM. When ECM is commanding a component on, voltage of control circuit should be low (near zero). When ECM is commanding control circuit to component off, voltage potential of circuit should be high (near battery voltage). If fault detection circuit senses a voltage other than what is expected, this DTC will set.

ECM will monitor injector circuit for short to ground, short to voltage, open circuit or an internally shorted or excessively low resistance at injector. If ECM detects any of these malfunctions, this DTC will set and affected driver will be disabled. ECM will continue to test circuit and if fault disappears, driver will be reactivated.

Conditions required to set DTC are:

• Ignition voltage is 9-17 volts.
• Engine speed greater than 80 RPM.
• An injector circuit fault is detected.