Cummins ISX12 CM2250 (2010-12) Fault Code: 238 PID: 105 SPN: 3511 FMI: 4 Sensor Supply 3 Circuit- Voltage Below Normal or Shorted to Low Source

Circuit Description
The sensor supply 3 circuit provides a 5 volt supply to the primary engine speed/position sensor.

Component Location
Not Applicable

Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes
The electronic control module (ECM) detects that the sensor supply 3 signal voltage is less than a 4.8 VDC for more than 1 second.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
The backup engine speed sensor will be used by the ECM for the engine speed signal.
Conditions for Clearing the Fault Code
To validate the repair, start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.
For OBD engines, the ECM will turn off the MIL after 3 consecutive trips where the diagnostic runs and passes.
The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD engines.

Shop Talk
The ECM monitors the voltage level on the engine speed sensor +5 volt supply circuit. If the voltage falls below a calibratible limit, this fault is recorded.

Possible causes of this fault code:

Short circuit to ground in the engine harness, sensor, or ECM.

Possible Cause:
1) Crankshaft position Sensor failure
2) Engine Harness
3) ECM calibration