Cummins ISC CM2150 (2007-09) Fault Code: 1938 PID: SPN: 3597 FMI: 1 ECU Power Output Supply Voltage 1 - Data Valid but Below Normal Operational Range - Moderately Severe Level. Low battery voltage detected by the VGT actuator.

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.

This fault code is logged when the voltage to the VGT actuator drops below +10-VDC. The VGT will still continue to respond to commands from the primary engine ECM.

Possible repairs:

1)Tighten the loose connections and clean the terminals.
2)Charge or replace the batteries.
3)Repair or replace the OEM power harness.