Cummins ISX CM870 (2003-06) Fault Code: 2375 PID: P412 SPN: 412 FMI: 3/3 Exhaust Gas Recirculation Temperature Sensor Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at EGR temperature circuit.

Beginning with engine serial number (ESN) 14039654, the temperature sensor return circuit was separated from the pressure sensor return circuit. For ESNs prior to this and with engine wiring harness, Part Number 3682854, refer to the Common Pressure/Temperature Sensor Return Circuit above. For this ESN and greater or for any other engine wiring harness part number, refer to the Separate Pressure/Temperature Sensor Return Circuit above.

This fault code is set active if the sensor signal voltage is above the normal operating range for the sensor and the ECM has commanded the EGR valve open. This fault code will not be set active if the ECM has commanded the EGR valve closed. However, once the fault code is set, it will remain active independent of whether the EGR valve is open or closed.

The EGR temperature sensor shares return wires in the engine harness with other sensors. An open return can cause multiple fault codes to be active. Before troubleshooting Fault Code 2375, check for multiple fault codes.

Possible causes:

1)Open return circuit in the harness, connectors, sensor, or ECM
2)Open signal circuit or shorted to a voltage source.

Possible repairs:

1)Replace the EGR temperature sensor.
2)Repair or replace the engine harness.
3)Replace the ECM.