Fuel Injector operation is controlled by the Engine Control Module (ECM). The ECM provides a common supply voltage to injectors 1,2,3 (Bank 1) and there are individual output transistor drivers inside the ECM to control each individual injector?s ground circuits. There are two solenoid circuits within the injector; a Needle Control Valve and a Spill Valve. Although they are separate circuits, the same fault code is used to identify a fault in the Needle Control Valve circuit and/or the Spill Valve circuit.

Conditions for diagnostic trouble code (DTC):
1) Injector (INJ) activated
2) Cylinder balancing data too high

Observable symptoms
1) Low Power
2) Uneven operation
3) Abnormal noise

Probable cause
1) Excessive wear or damage to cylinder liners, piston, or piston rings
2) Valves and rocker arms
3) Camshaft
4) VCB control valve sticking or slow to close
5) Injector 1