Cummins ISX12 CM2250 (2010-12) Fault Code: 3727 PID: SID 254 SPN: 5571 FMI: 7 High-Pressure Common Rail Fuel Pressure Relief Valve- Mechanical System Not Responding or Out of Adjustment

Circuit Description
The high-pressure relief valve is a mechanical device that opens when the fuel pressure in the fuel rail exceeds a critical warning limit.

Component Location
The high-pressure relief valve is located on the fuel rail.

Conditions for Running the Diagnostics
This diagnostic runs continuously when the engine is operating.

Conditions for Setting the Fault Codes
The ECM has detected that the fuel pressure relief valve has opened at a pressure lower than expected.

Action Taken When the Fault Code is Active
This is a no lamp fault, which will be set in conjunction with Fault Code 1911. The ECM will illuminate the amber CHECK ENGINE lamp and/or the malfunction indicator lamp (MIL) for Fault Code 1911.
Conditions for Clearing the Fault Code
The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately following each key cycle or when the relief valve is able to reset itself and the diagnostic runs and passes.
The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults.

Shop Talk
This fault code will become inactive at each key OFF event, and will not become active again until the fault condition reoccurs. Troubleshoot inactive or active occurences of this fault code the same.

An occurence of this fault indicates that the high-pressure relief valve is being tripped at a pressure lower than what is expected. If this has happened multiple times, there will be many occurences of this fault. Troubleshoot Fault Code 3727 before Fault Code 1911, if both fault codes are present in the ECM.

This fault code may also be triggered by a sudden and significant loss of fuel pressure in the fuel system.

Possible Cause:
1) ECM calibration