Cummins ISM CM870 (2003-06) Fault Code: 584 PID: S39 SPN: 677 FMI: 3/3 Starter Relay Driver Circuit – Voltage Above Normal or Shorted to High Source. Open circuit or high voltage detected at starter lockout circuit.

The ECM monitors the voltage level on this circuit. If it detects a voltage when the signal is commanded off, it records this fault code.

Possible causes:

1)Open circuit in the starter lockout relay, OEM harness, or connectors
2)Short circuit to a voltage source in the OEM harness or relay.
This fault can also be set active if the over crank protection feature (starter lockout) is enabled, but the engine/ECM is not wired to support it.

Possible repairs:

1)Replace the starter lockout relay.
2)Repair or replace the OEM harness.
3)Repair the source of the failed ground connection.