Cummins ISB CM850 (2003-06) Fault Code: 2383 PID: SID 27 SPN: 641 FMI: 5 Variable Geometry Turbocharger actuator circuit – current below normal, or open circuit.

Posted by PerDiezel Solutions on January 18, 2026

The ECM monitors the voltage level of this circuit and logs a fault code if the voltage level indicates an open circuit or short to voltage source is present. This fault is always set inactive when the keyswitch is turned on. If the fault condition reoccurs while the keyswitch is in the ON position, the fault code will be set active. Since active faults are set inactive at key-on, this troubleshooting tree should be used to troubleshoot active and inactive faults.

Possible causes:

1)An open circuit in the engine harness, connectors, motor, or ECM
2)Turbocharger actuator motor signal (+ or -) leads shorted to a voltage source in the engine harness or ECM.

Do not supply voltage of any kind to the EGR valve motor. This circuit uses a pulse-width-modulated signal and direct voltage can permanently damage the motor.

Possible repairs:

1)Replace the turbocharger.
2)Repair or replace the engine harness.
3)Replace the ECM.
4)The removal and installation of the connector may correct the fault.

Cummins ISB CM850 (2003-06) Fault Code: 2382 PID: SPN: 2795 FMI: 4 Turbocharger position sensor circuit – shorted low. Low signal voltage detected at the turbocharger position sensor circuit.

Cummins ISB CM850 (2003-06) Fault Code: 2381 PID: SPN: 2795 FMI: 4 Turbocharger position sensor circuit – shorted high. High signal voltage detected at the turbocharger position sensor circuit.

Cummins ISB CM850 (2003-06) Fault Code: 2377 PID: SID 33 SPN: 647 FMI: 3 Fan Control Circuit – Voltage Above Normal or Shorted to High Source. Open circuit or high voltage detected at the fan control circuit.

Cummins ISB CM850 (2003-06) Fault Code: 2376 PID: 412 SPN: 412 FMI: 2 Recirculation Exhaust Gas (EGR) Temperature Sensor Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the EGR temperature circuit.

Cummins ISB CM850 (2003-06) Fault Code: 2375 PID: 412 SPN: 412 FMI: 3 EGR Temperature Sensor Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at the EGR temperature sensor circuit.

Cummins ISB CM850 (2003-06) Fault Code: 2374 PID: 95 SPN: 1209 FMI: 4 Exhaust gas pressure sensor circuit – shorted low. Low voltage detected on the exhaust gas pressure sensor exhaust circuit.

WARNING!