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Reason:Aftertreatment Fuel Shutoff Valve 1 – Data Erratic, Intermittent, or Incorrect. An error has been detected in the aftertreatment fuel shutoff valve or the aftertreatment fuel injector system. Effect:Possible reduced engine performance Circuit Description:Before active regeneration of the aftertreatment DPF, a diagnostic test on the system is performed. The aftertreatment fuel injector opens and relieves fuel pressure in the line. The aftertreatment fuel pressure sensor must be reading atmospheric pressure at this point in the test. The aftertreatment fuel drain valve closes. The aftertreatment fuel shutoff valve and aftertreatment fuel injector then close and trap the fuel between the aftertreatment...

Reason:Aftertreatment Fuel Pressure Sensor Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the aftertreatment fuel pressure sensor circuit Effect:Possible reduced engine performance Circuit Description:The aftertreatment fuel pressure sensor is used to monitor the fuel pressure into the aftertreatment system. The engine control module (ECM) supplies the aftertreatment fuel pressure sensor a 5 volt reference voltage. When the fuel pressure is low, the sensor signal voltage is low. When the fuel pressure is high, the sensor signal voltage is near the 5 volt reference voltage. The ECM monitors the aftertreatment fuel pressure signal circuit...

Reason:ECU Power Output Supply Voltage 1 – Voltage Above Normal or Shorted to High Source. High battery voltage detected by the variable geometry turbocharger actuator. Effect:None on performance Circuit Description:The variable geometry turbocharger (VGT) is electronically activated by the VGT actuator. The VGT actuator is a smart device and receives information via the J1939 data link from the primary engine control module (ECM). The VGT actuator performs its own diagnostics and reports malfunctions back to the primary engine ECM, using the J1939 data link. The ECM then decodes the error message and converts it to a fault code. Component Location:The...

Reason:Crankcase Pressure – Data Erratic, Intermittent, or Incorrect. The ECM has detected that the crankcase pressure signal is reading an erratic value at initial key ON or during engine operation. Effect:None on performance Circuit Description:The crankcase pressure sensor is used to monitor the pressure inside the crankcase. The engine control module (ECM) supplies the crankcase pressure sensor a 5 volt reference voltage. When the crankcase pressure is low, the sensor signal voltage is low. When the crankcase pressure is high, the sensor signal voltage is near the 5 volt reference voltage. The ECM monitors the crankcase pressure signal circuit voltage...

Reason:Ambient Air Density – Data Valid But Below Normal Operational Range – Least Severe Level. Engine torque has been reduced because the vehicle was operating at a high altitude condition. Effect:Possible reduced engine performance Circuit Description:The engine control module (ECM) monitors the ambient air pressure using either an ambient air pressure sensor or a combination turbocharger compressor intake pressure/temperature sensor. These sensors respond to pressure changes in the atmosphere, which occur based on the elevation where the engine is currently operating. This pressure sensor has a 5 volt supply circuit, a sensor signal voltage, and a return circuit. The ambient...