Cumminz

Circuit DescriptionThe engine control module (ECM) monitors engine operating conditions, including the reading of rail fuel pressure, and changes the flow command to either increase (OPEN the fuel pump actuator) or decrease (CLOSE the fuel pump actuator) the fuel supply to the high-pressure pump. Component LocationThe fuel pump actuator is installed on the high-pressure fuel pump. The high-pressure relief valve is located on the fuel rail. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine is operating. Conditions for Setting the Fault CodesThe ECM has verified that the fuel rail pressure has exceeded the fuel pressure relief valve...

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 errors back to the primary engine ECM using the J1939 data link. 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. Conditions for Setting the Fault CodesThe fault code is set when the voltage supplied to the VGT...

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 in the crankcase filter assembly. Conditions for Running the DiagnosticsThis diagnostic consists of two parts. The...

Circuit DescriptionThe ambient air pressure sensor responds to pressure changes in the atmospheric pressure. The pressure changes occur based on elevation that the engine is currently operating at. The ambient air pressure sensor has a 5 volt supply circuit, a sensor signal voltage, and a return circuit. The engine control module (ECM) provides a 5 volt supply to the ambient air pressure sensor on the sensor supply 1 circuit. The ECM also provides a ground on the sensor return circuit. The ambient air pressure sensor provides a signal to the ECM on the ambient air pressure sensor signal circuit. This...

Circuit DescriptionThe electronic control module (ECM) supplies a 5 volt supply to the engine coolant level sensor using a common sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The engine coolant level sensor provides a signal to the ECM on the engine coolant level sensor signal circuit. This sensor signal voltage changes based on the coolant level in the expansion tank. Component LocationThe engine coolant level sensor is typically located in the radiator top tank or surge tank. Refer to the OEM service manual for location. Conditions for Running the DiagnosticsThis diagnostic runs continuously...