Cumminz

Circuit DescriptionThe intake manifold 1 temperature sensor is a variable resistor sensor and is used to measure the temperature of the air entering the intake manifold of the engine. The engine intake manifold temperature value is used by the electronic control module (ECM) for the engine protection system and engine emission control. The ECM supplies 5 volts to the intake manifold temperature signal circuit, and monitors the change in voltage caused by changes in the resistance of the sensor to determine the intake manifold temperature. When the intake air is cold, the sensor (or thermistor) resistance is high. The ECM...

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. There is one 30-ampere fuse in the unswitched battery wires to protect the original equipment manufacturer (OEM) harness. The ECM receives switched battery input through the vehicle keyswitch wire when the vehicle keyswitch is turned ON. The battery return wires are connected directly to the negative (-) battery post. Component LocationThe ECM is connected to the battery by the OEM harness. This direct link provides a constant power supply for the ECM. The...

Circuit DescriptionThe electronic control module (ECM) receives constant voltage from the batteries through the unswitched battery wires that are connected directly to the positive (+) battery post. There is one 30-ampere fuse in the unswitched battery wire to protect the original equipment manufacturers (OEM) harness. The ECM receives switched battery input through the vehicle keyswitch wire when the vehicle keyswitch is turned ON. The battery return wires are connected directly to the negative (-) battery post. Component LocationThe ECM is connected to the battery by the OEM harness. This direct link provides a constant power supply for the ECM. The...

Circuit DescriptionThe air shutoff valve is either an original equipment manufacturer (OEM) or Cummins® installed component that shuts off the flow of air into the intake of the engine in order to prevent an engine overspeed condition. When activated, the engine control module (ECM) supplies 12 VDC to the air shutoff solenoid. This solenoid then activates the valve, closing a plate over the intake. Component LocationThe air shutoff valve is either an OEM or Cummins® installed component, and is usually located on the air intake connection. Conditions for Running the DiagnosticsThis diagnostic only runs during an Air Shutoff Valve Test....

Circuit DescriptionThe electronic control module (ECM) monitors engine-operating conditions, including the reading of fuel rail pressure, and changes the flow command to either increase (OPEN the fuel pump actuator) or decrease (CLOSE the fuel pump actuator) the fuel supply to the high-pressure pump. Component LocationThe high-pressure relief valve is located on the fuel rail. The fuel pump actuator is located on the engine-mounted fuel pump Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine is running. Conditions for Setting the Fault CodesThe ECM has detected that the measured fuel rail pressure has been above the maximum pressure allowed...