Hello, my name is Joe
Fault 655 is a generic code for Cummins fault code 312.
Injector Solenoid Driver Cylinder 5 Circuit - Current Above Normal or Grounded Circuit.
This means that the ECM is detecting a small amount of current at injector Number 5 when the voltage is turned off.
When this occurs, the ecm will shut off current to injector, and the engine can possibly misfire or run rough.
The injector solenoid valves are actuated by the electronic control module (ECM) to control fuel metering and timing. Each injector solenoid is connected to the ECM by a supply and a return wire.
An electrical pulse is sent to the injector from the ECM on the supply wire and returns to the ECM on the return wire after actuating the solenoid.
Each solenoid valve is normally open, and it is only closed by an electrical pulse from the ECM during fuel injection and metering.
The internal actuator harness is located on the inside of the rocker lever housing on the right side. It has six connectors spaced along its length - one for each injector solenoid. These connectors attach to the pigtail connector on each injector...
Possible causes of the fault 312 include :
Open circuit in the engine harness, connectors, or actuator.
Short circuit to ground in the engine harness or injector.
Short circuit to voltage source in the engine harness.
Or a defective injector.
If the issue is intermittent, it is possible for the engine to run normal most of the time.
Troubleshooting will need to be done to isolate the exact cause of the fault code. It could be an issue with the engine harness, injector harness, or a faulty injector.