Circuit DescriptionThe air shutoff valve is either an original equipment manufacturer (OEM) or Cummins 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 activates the valve, closing a plate over the intake.

Component LocationThe air shutoff valve is either an OEM or Cummins? installed component, and is usually located on the air intake connection.

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

Conditions for Setting the Fault CodesThe ECM has detected that engine speed was greater than 2500 rpm for 0.25 seconds, or the operator manually tripped the engine air shutoff valve.

Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE lamps immediately when the diagnostic runs and failsThe air shutoff valve closesEngine fueling is set to zeroThe engine starter will be locked out.Conditions for Clearing the Fault CodeTo validate the repair, the air shutoff valve must be manually reset to the open position. Then 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.

Shop TalkThis fault code indicates that the engine has been shut down via the engine air shutoff valve. This can occur automatically (engine overspeed condition) or manually (activating the engine air shutoff valve switch in the cab). In either case, this fault code will become active until the valve is de-activated.

Possible Cause:1) Engine Damaged2) ECM failure