Cummins ISX12 CM2250 (2010-12) Fault Code: 386 PID: SID 212 SPN: 3509 FMI: 3 Sensor Supply 1 Circuit- Voltage Above Normal or Shorted to High Source

Circuit Description
The sensor supply 1 of the Electronic Control Module (ECM) provides a 5 volt supply for the Exhaust Gas Recirculation (EGR) differential pressure sensor, exhaust gas pressure sensor, EGR valve position sensor, and EGR orifice pressure sensor (if equipped).

Component Location
Sensor supply 1 is located in the ECM and provides a 5 volt supply to various engine sensors. The supply voltage is spliced off in the engine harness to each sensor it supports.

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

Conditions for Setting the Fault Codes
The ECM detects that the sensor supply 1 signal voltage is greater than 5.25-VDC for more than 1 second.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE light and/or Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
A default value is used for all the sensors on the sensor supply 1 circuit.
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 On-Board Diagnostic (OBD) engines, the ECM will turn off the MIL after three 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 applications

Shop Talk
High voltage on the (+) 5 volt supply line can be caused by a short to battery voltage in the engine harness or connectors, or a malfinctioning ECM.

Possible Cause:
1) Engine Harness
2) ECM calibration