Cumminz

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. Conditions for Setting...

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 presently operating at. The ambient air pressure sensor has a 5 volt supply circuit, a sensor signal voltage, and a return circuit. The ambient air pressure sensor provides a signal to the ECM on the ambient air pressure sensor signal circuit. This sensor signal voltage changes based on the pressure of the atmosphere. The ECM will detect a low signal voltage when the vehicle is operating at high altitudes. The ECM will detect a high...

Circuit DescriptionThe electronic 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 sensor signal voltage changes based on the pressure of the atmosphere. The ECM will detect a low signal voltage when the vehicle is operating at high altitudes. The ECM will detect a high signal voltage when the vehicle is operating at sea level altitudes. Component LocationThe...

Circuit DescriptionThe fuel lift pump circuit is a discrete output in the engine control module (ECM) that controls the electric fuel lift pump. The lift pump is grounded in the ECM. Component LocationThe electric fuel lift pump is located behind the ECM cooling plate on the intake side of the engine. Conditions for Running the DiagnosticsThis diagnostic runs when the keyswitch is in the ON position and the lift pump timer has expired 1 minute after intial key ON. Conditions for Setting the Fault CodesThe engine fuel lift pump signal circuit is detected to be greater than 0-VDC when the...

Circuit DescriptionThe fuel lift pump circuit is a discrete output in the engine control module (ECM) that controls the electric fuel lift pump. The lift pump is grounded in the ECM. Component LocationThe electric fuel lift pump is located behind the ECM cooling plate on the intake side of the engine. Conditions for Running the DiagnosticsThis diagnostic runs during the first minute after initial key ON, when the fuel lift pump is being commanded to run. Conditions for Setting the Fault CodesThe engine fuel lift pump signal circuit is detected to be 0-VDC when the signal is turned on by...