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Reason:Engine Fan Clutch 2 Control Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the fan control circuit when commanded ON. Effect:The fan can stay on continuously or not run at all. Circuit Description:The fan control circuit is a device used by the engine to control the fan operation. When the engine control module (ECM) energizes the fan control circuit, the engine fan is engaged. The fan control circuit utilizes a pulse width modulated (PWM) signal. A PWM signal is a pulsed voltage signal between 0-VDC and system voltage. The frequency of the pulsed...

Reason:Aftertreatment Diesel Exhaust Fluid Tank Level – Data Valid But Below Normal Operating Range – Most Severe Level. The aftertreatment diesel exhaust fluid tank level has fallen below the critical warning level. Effect:Possible reduced engine performance Circuit Description:The aftertreatment diesel exhaust fluid level sensor is used to monitor the diesel exhaust fluid level inside the diesel exhaust fluid tank. Component Location:The aftertreatment diesel exhaust fluid tank level sensor is located in the aftertreatment diesel exhaust fluid tank. Location of the tank and level sensor is OEM dependent. Refer to the OEM service manual. Conditions for Running the Diagnostics:This diagnostic runs...

Reason:Aftertreatment Fuel Pressure Sensor – Data Erratic, Intermittent, or Incorrect. The ECM has detected that the aftertreatment fuel pressure signal is not changing with engine operating conditions. 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...

Reason:Aftertreatment Fuel Pressure Sensor Circuit – Voltage Above Normal or Shorted to High Source. High 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:Aftertreatment Doser – Data Erratic, Intermittent, or Incorrect. An internal or external fuel leak has been detected in the aftertreatment fuel 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 fuel shutoff valve and the aftertreatment...