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Reason:Engine Exhaust Gas Recirculation Outlet Pressure Sensor Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the EGR orifice pressure sensor. Effect:Possible reduced engine performance. Circuit Description:The engine control module (ECM) provides a 5 volt supply to the EGR orifice pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The EGR orifice pressure sensor provides a signal to the ECM on the EGR orifice pressure sensor signal circuit. This sensor signal voltage changes based on the pressure at the EGR orifice pressure sensor. Component Location:The...

Reason:Engine Exhaust Gas Recirculation Outlet Pressure – Data Erratic, Intermittent or Incorrect. The EGR orifice pressure sensor is reading an erratic value at initial key ON or while the engine is running. Effect:Possible reduced engine performance Circuit Description:The engine control module (ECM) provides a 5 volt supply to the EGR orifice pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The EGR orifice pressure sensor provides a signal to the ECM on the EGR orifice pressure sensor signal circuit. This sensor signal voltage changes based on the pressure at the EGR...

Reason:Engine Air Shutoff Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at the air shutoff circuit. Effect:The engine air shutoff valve will be disabled. Circuit Description:The air shutoff valve is an optional component used to shutdown the engine in the event of an engine overspeed condition. It can be closed via a manual shutdown switch or via an ECM command. Component Location:The engine air shutoff valve location can vary depending on the OEM. Refer to the OEM service manual. Conditions for Running the Diagnostics:This diagnostic runs continuously when the keyswitch is in the ON...

Reason:Engine Air Shutoff Sensor Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the engine air shutoff circuit. Effect:The engine air shutoff valve will be disabled. Circuit Description:The air shutoff valve is an optional component used to shutdown the engine in the event of an engine overspeed condition. It can be closed via a manual shutdown switch or via an ECM command. Component Location:The engine air shutoff valve location can vary depending on the OEM. Refer to the OEM service manual. Conditions for Running the Diagnostics:This diagnostic runs continuously when the keyswitch is in...

Reason:Aftertreatment SCR Intake Temperature Sensor Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at the SCR intake temperature sensor circuit. Effect:Possible reduced engine performance. Circuit Description:The aftertreatment SCR (selective catalytic reduction) temperature sensor module is a smart device that communicates with the engine control module via the J1939 data link. The aftertreatment SCR temperature sensor module performs its own internal diagnostics and reports malfunctions back to the engine control module using the J1939 data link. The aftertreatment SCR temperature sensor module is used to measure the aftertreatment SCR intake temperature and aftertreatment SCR outlet...