Cummins ISC CM2150 (2007-09) Fault Code: 297 PID: 443 SPN: 1388 FMI: 3 Auxiliary Pressure Sensor Input 1 Circuit - Voltage Above Normal or Shorted to High Source. High signal voltage detected at the OEM pressure circuit.

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM.
Possible causes:

1)Open return circuit in the harness, connectors, or sensor
2)Signal circuit shorted to sensor supply or battery voltage.

Possible repairs:

1)Replace the OEM pressure sensor.
2)Replace the ECM.