Cumminz

Circuit DescriptionBefore active regeneration of the aftertreatment diesel particulate filter, 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 injector closes and the aftertreatment purge air actuator opens. This pressurizes the aftertreatment fuel system to vehicle air pressure. The diagnostic then checks to make sure the aftertreatment fuel pressure sensor is reading vehicle air pressure. The aftertreatment fuel shutoff valve then opens and allows pressurized fuel to enter the system....

Circuit DescriptionThe coolant level sensor is a switch and is used to measure the level of the engine coolant in the radiator top tank. The coolant level sensor is immersed in the coolant and returns a different signal voltage when immersed in coolant versus being out of coolant. The engine control module (ECM) monitors the change in the signal voltage to determine the level of the engine coolant. Component LocationThe engine coolant level sensor is typically located in the radiator top tank or surge tank. Refer to the OEM service manual for the location. Conditions for Running the DiagnosticsThis diagnostic...

Circuit DescriptionThe 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 to calculate the pressure of the air within the crankcase. Component LocationThe crankcase pressure sensor is located near the crankcase ventilation filter. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine...

Circuit DescriptionThe 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 LocationThe VGT actuator is located on the turbocharger bearing housing. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in the ON position or when the...

Circuit DescriptionThe aftertreatment fuel injector is electronically controlled by the engine electronic control module (ECM) through a pulse width modulated (PWM) signal. The amount of fuel injected is determined by how long the PWM signal to the injector is on. Component LocationThe aftertreatment fuel injector is installed in the exhaust system in the turbocharger adapter pipe. The aftertreatment fuel pressure sensor and aftertreatment fuel shutoff valve are installed in the shutoff valve manifold. The aftertreatment purge air actuator is located above the shutoff valve manifold. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in the ON...