Cumminz

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 DescriptionDevices such as ABS controllers, autoshift transmissions, ASR systems, electronic displays, electronic information systems, electronic service tools, and vehicle electronic control unit(s) (VECUs) can communicate with the ECM over the SAE J1939 data link. Messages sent from the devices are received by the ECM and used for controlling the engine. The ECM also transmits information to these devices over the SAE J1939 data link. Component LocationThe SAE J1939 data link wiring and the SAE J1939 devices vary by OEM options. Refer to the OEM service manual. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in...

Circuit DescriptionThe aftertreatment diesel exhaust fluid controller is the central control for the SCR diesel exhaust fluid dosing system, and handles the dosing activity, tank level sensing, tank temperature sensing, line heating, and tank heating. It communicates to the engine via ECM via a J1939 data link connection. Component LocationThe location of the aftertreatment diesel exhaust fluid controller varies by application and OEM. The controller will typically be mounted to the vehicle frame or suitable rigid bracket using 3 or 4 capscrews. Refer to the OEM service manual for a more detailed component location description. Conditions for Running the DiagnosticsThis...

Circuit DescriptionThe overcrank protection feature (or starter lockout) is designed to prevent damage to the starter motor during hard start conditions. Excessive cranking of the engine can cause the starter motor to overheat, resulting in permanent damage. When excessive engine cranking is detected, the overcrank protection feature locks out the starter until the starter motor has adequately cooled, and is safe to operate again. Component LocationThe overcrank protection feature is controlled by the engine control module (ECM), and can not be modified. Conditions for Running the DiagnosticsThis diagnostic runs when the engine is being started. Conditions for Setting the Fault...

Circuit DescriptionThe aftertreatment diesel exhaust fluid dosing unit air solenoid is used to enable and disable the truck air supply to the diesel exhaust fluid dosing unit. The air is used to transport the diesel exhaust fluid to the aftertreatment nozzle. Component LocationThe aftertreatment diesel exhaust fluid dosing unit air solenoid is mounted to the back of the diesel exhaust fluid dosing unit. The mounting location of the diesel exhaust fluid dosing unit is OEM specific. Conditions for Running the DiagnosticsThis diagnostic runs continuously while the Selective Catalytic Reduction (SCR) system is dosing diesel exhaust fluid into the aftertreatment system....