Cummins ISB CM850 (2003-06) Fault Code: 584 PID: SID 39 SPN: 677 FMI: 3 Starter Relay 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.

Possible repairs:

1)Replace the starter lockout relay.
2)Replace the OEM harness.
3)The removal and installation of the connector may correct the fault.
4)Replace the ECM.