Circuit DescriptionThe engine control module (ECM) receives constant voltage from the batteries through the unswitched battery wires that are connected directly to the positive (+) battery post. The ECM receives switched battery input through the vehicle keyswitch wire when the vehicle keyswitch is turned ON. Component LocationThe ECM is connected to the battery by the OEM harness. This direct link provides a constant power supply for the ECM. The location of the battery will vary with the original equipment manufacturer (OEM). Refer to the OEM service manual. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in...

Circuit DescriptionThe aftertreatment intake NOx (nitrogen oxides) sensor is a smart device and communicates with the engine control module (ECM) via the J1939 data link. The aftertreatment intake NOx sensor performs internal diagnostics and reports malfunctions back to the primary ECM using the J1939 data link. The NOx sensor is permanently attached to the NOx control module. They are serviced as a single component and can not be replaced individually. The aftertreatment intake NOx sensor is used to measure the NOx emissions at the intake of the aftertreatment system. Component LocationThe aftertreatment intake NOx sensor is mounted on the engine...

Circuit DescriptionThe Orginal Equipment Manufacturer (OEM) wiring harness connects multiple outputs or switched inputs to the ECM which can be enabled or disabled using INSITE™ electronic service tool, such as such as the accelerator interlock/engine torque limit switch or the clutch/engine protection override switch. Many of the outputs and switched inputs share a common wire on the OEM wiring harness. Refer to the engine wiring diagram to determine which features share common wires in the OEM harness. Component LocationNot Applicable Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in the ON position or when the engine...

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 DescriptionThe real-time clock consists of a timing chip internal to the engine control module (ECM) which monitors engine off time, i.e. how long the engine has been shut down. Component LocationThe real time clock is a timing chip internal to the ECM and can not be serviced separately. Conditions for Running the DiagnosticsThis diagnostic runs at initial key ON. Conditions for Setting the Fault CodesThe engine off timer was not counting correctly and does not match other timers in the ECM. Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator...