Cumminz

Circuit DescriptionThe SCR intake temperature sensor is used by the electronic control module (ECM) to monitor the engine exhaust temperature entering the SCR catalyst. The ECM monitors the voltage on the SIGNAL pin and converts this to a temperature value. Component LocationThe SCR intake temperature sensor is located in the aftertreatment system. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine is running. Conditions for Setting the Fault CodesThe ECM detects that the temperature at the SCR catalyst intake is greater than a calibratible value. Action Taken When the Fault Code is Active-The ECM illuminates the amber CHECK...

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. Component values and states from components such as sensors, accelerators, and switches can then 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 DescriptionUnder ordinary operating conditions, the real-time clock in the electronic control module (ECM) is powered by the vehicle’s batteries. If battery power to the ECM is lost, then the real-time clock will be powered by a battery in the engine harness (if equipped). Component LocationThe real-time clock battery is secured to the engine harness near the ECM. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in the ON position. Conditions for Setting the Fault CodesThe ECM detects that the real-time clock battery voltage is 3.3-VDC. Action Taken When the Fault Code is Active-The ECM flashes...

Circuit DescriptionThe injector solenoid valves are actuated by the electronic control module (ECM) to control fuel metering and timing. Each injector solenoid is connected to the ECM by a supply and a return wire. An electrical pulse is sent to the injector from the ECM on the supply wire and returns to the ECM on the return wire after actuating the solenoid. Each solenoid valve is normally open, and it is only closed by an electrical pulse from the ECM during fuel injection and metering. Component LocationThe ISM has an internal actuator harness that connects to the external engine harness...

Circuit DescriptionThe injector solenoid valves control fueling quantity and injection timing. The electronic control module (ECM) energizes the solenoid by closing a high-side and a low-side switch. There are two high-side switches and four low-side switches inside the ECM. The injectors for cylinder numbers 1 and 2 (front bank) share a single high-side switch that connects the injector circuit to the source of high voltage inside the ECM. Likewise, the injectors for cylinder numbers 3 and 4 (rear bank) also share a single high-side switch. Each injector circuit has a dedicated low-side switch that completes the circuit path to ground...