Circuit DescriptionBetween each injection event, the electronic control module (ECM) attempts to recharge the injector power supply. The injector power supply consists of a bank of capacitors; this power supply is maintained at high voltage. Recharging is accomplished by recovering energy stored in the injector solenoids. For the injector power supply to remain fully charged, there must be good ECM battery power and ground, a good engine speed sensor, and good injector circuits. Component LocationThe injector power supply is located inside the ECM Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine speed is greater than 500 rpm,...

Circuit DescriptionThe sensor supply 1 of the electronic control module (ECM) provides a 5 volt supply for multiple engine sensors. Component LocationSensor supply number 1 is located in the ECM engine harness connector and provides a 5 volt supply to various sensors. The supply voltage is spliced off in the engine harness to each sensor it supports. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in the ON position or when the engine is operating. Conditions for Setting the Fault CodesThe ECM detects that the sensor supply 1 signal voltage is less than 4.75-VDC for more...

Circuit DescripitonNormally, switches, accelerators, and other components are connected to the engine control module (ECM) directly through individual wires. Multiplexing allows those same components to be hard wired to an original equipment manufacturer (OEM) vehicle electronic control unit (VECU) or transmission electronic control unit (ECU) in the cab. Then component values and states from components such as sensors, accelerators, and switches can be transmitted from the OEM VECU to the Cummins® ECM over the SAE J1939 data link. Messages sent from OEM VECUs or transmission ECUs are received by the Cummins® ECM and used for controlling the engine. The Cummins®...

Circuit DescriptionNormally, switches, accelerators, and other components are connected to the engine control module (ECM) directly through individual wires. Multiplexing allows those same components to be hard wired to an original equipment manufacturer (OEM) vehicle electronic control unit (VECU) or transmission electronic control unit (ECU) in the cab. Then component values and states from components such as sensors, accelerators, and switches can be transmitted from the OEM VECU to the Cummins® ECM over the SAE J1939 data link. Messages sent from OEM VECUs or transmission ECUs are received by the Cummins® ECM and used for controlling the engine. The Cummins®...

Circuit DescriptionNormally, switches, accelerators, and other components are connected to the engine electronic control module (ECM) directly through individual wires. Multiplexing allows those same components to be hard wired to an OEM VECU or transmission electronic control unit in the cab. Then component values and states from components (such as sensors, accelerators, and switches) can be transmitted from the OEM VECU to the Cummins® engine ECM over the SAE J1939 data link. Messages sent from the OEM Vehicle Electronic Control Unit (VECU) or transmission electronic control unit are received by the Cummins® engine ECM and used for controlling the engine....