Cummins ISX12 CM2250 (2010-12) Fault Code: 5221 PID: SPN: 3667 FMI: 2 Engine Air Shutoff Status- Data Erratic, Intermittent, or Incorrect

Circuit Description
The air shutoff valve position switch is located inside the air shutoff valve. During testing, the engine is accelerated and the air shutoff valve closes at a predetermined engine speed. When the air shutoff valve closes, the position switch closes. The engine control module (ECM) monitors the air shutoff valve position signal circuit for a change indicating the switch closed.

Component Location
The air shutoff valve position switch is located inside the air shutoff valve. The air shutoff valve is either an original equipment manufacturer (OEM) or Cummins? installed component, and is usually located on the air intake connection.

Conditions for Running the Diagnostics
This diagnostic only runs during an Air Shutoff Valve Test.

Conditions for Setting the Fault Codes
The ECM detects the air shutoff valve position switch has not closed.

Action Taken When the Fault Code is Active
The ECM illuminates the red CHECK ENGINE lamp and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails.
Conditions for Clearing the Fault Code
To clear the fault code and validate the repair, the air shutoff valve must be reset. The Air Shutoff Valve Test must be performed and the ECM must see the air shutoff valve position switch close.

Shop Talk
Possible causes of this fault code include:

Malfunctioning air shutoff valve position solenoid
Malfunctioning air shutoff valve
Malfunctioning air shutoff valve position switch
Broken or disconnected air shutoff position switch SIGNAL wire
Broken or disconnected air shutoff position switch RETURN wire.

Possible Cause:
1) OEM air shutoff solenoid failure
2) ECM calibration