Cummins ISB4.5 CM2150 Fault Code: 3139 PID: SPN: 3667 FMI: 3 Engine Air Shutoff Circuit – Voltage Above Normal or Shorted to High Source.

Circuit Description
The engine air shutoff valve is an original equipment manufacturer (OEM) installed component that shuts off the flow of air into the intake of the engine in order to prevent an engine overspeed condition. When activated, the engine control module (ECM) supplies 12 VDC to the air shutoff solenoid. This solenoid then supplies air to the air shutoff valve and activates the valve, closing a plate over the intake.

Component Location
The engine air shutoff valve location can vary, depending on the OEM. See equipment manufacturer service information.

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 engine air shutoff driver is shorted to voltage.

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.

Conditions for Clearing the Fault Code
-To validate the repair, perform a keycycle, 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.
-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 On-Board Diagnostics applications.

Possible Causes
-Open engine air shutoff circuit
-Short circuit to voltage in the engine air shutoff circuit
-Malfunctioning ECM.

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.