0327740 JOHNSON ORIFICE, No. 68

Always determine the cause of the engine shutdown. Make necessary repairs before attempting to restart the engine.
Be familiar with the following items:
Types and locations of shutoff
Conditions which cause each shutoff to function
The resetting procedure that is required to restart the engineAlarms
The alarms are electrically operated. The operations of the alarms are controlled by the ECM.The alarm is operated by a sensor or by a switch. When the sensor or the switch is activated, a signal is sent to the ECM. An event code is created by the ECM. The ECM will send a signal to illuminate the lamp.Your engine may be equipped with the following sensors or switches:Coolant temperature - The coolant temperature sensor indicates high jacket water coolant temperature.Intake manifold air temperature - The intake manifold air temperature sensor indicates high intake air temperature.Intake manifold pressure - The intake manifold pressure sensor checks the rated pressure in the engine manifold.Fuel rail pressure - The fuel rail pressure sensor measures the high pressure or low pressure in the fuel rail. The ECM will Check the pressure.Engine oil pressure - The engine oil pressure switch indicates when oil pressure drops below rated system pressure, at a set engine speed.Engine overspeed - If the engine rpm exceeds the overspeed setting, the alarm will be activated.Air filter restriction - The switch checks the air filter when the engine is operating.User-defined switch - This switch can shut down the engine remotely.Water in fuel switch - This switch checks for water in the primary fuel filter when the engine is operating.Fuel temperature - The fuel temperature sensor monitors the pressurized fuel in the high-pressure fuel pump.NRS absolute pressure and NRS delta pressure - A combined pressure sensor across the NRS valve.Note: The sensing element of the coolant temperature sensor must be submerged in coolant to operate.Engines may be equipped with alarms to alert the operator when undesirable operating conditions occur.
When an alarm is activated, corrective measures must be taken before the situation becomes an emergency in order to avoid possible engine damage.
If corrective measures are not taken within a reasonable time, engine damage could result. The alarm will continue until the condition is corrected. The alarm may need to be reset.Note: If installed, the coolant level switch and the oil level switch are indicators. Both switches operate when the application is on level ground and the engine RPM at zero.Aftertreatment System
Diesel Oxidation Catalyst ____________________(DOC)
Selective Catalyst Reduction ____________________(SCR)
Diesel Particulate Filter ____________________(DPF)Soot Sensors - The soot sensor monitor the soot level within the DPF.NOx Sensors - Two NOx sensors monitor the NOx concentration within the exhaust gas before and after the selective catalyst reduction module.Temperature Sensor - A temperature sensor after the engine exhaust gas exit, after the DOC and before the SCR module monitor the temperatures within the system.DEF Tank Header Unit - The DEF level sensor monitors the volume of fluid in the tank and signals the ECM if the level drops below a given point.Testing
Turning the keyswitch to the ON position will check the indicator lights on the control panel. All the indicator lights will be illuminated for 2 seconds after the keyswitch is operated. Replace suspect bulbs immediately.Refer to Troubleshooting for more information.