COVER-OIL PUMP 1084107 - Caterpillar

Start/Stop Control
The ECM contains the logic and the outputs for control of engine prelubrication, of starting, of shutdown, and of postlube. The customer programmable logic responds to signals from the following components: engine control switch, emergency stop switch, remote start switch, data link, and other inputs.To control the engine at the appropriate times, the ECM provides +Battery voltage to the solenoids that control these components: prelube pump, starting motor and the gas shutoff valve.When the programmable logic determines that the prelubrication function is necessary, the ECM supplies +Battery voltage to the solenoid for the prelube pump. The prelubrication must develop sufficient engine oil pressure before the engine will crank. The engine has a pressure switch for the prelube. When the engine oil pressure is sufficient, the pressure switch closes. The engine will crank after the maintaining oil pressure for the programmed delay period.When the programmable logic determines the necessity to crank the engine, the ECM supplies +Battery voltage to the solenoid for the starting motor. Rotation of the crankshaft also operates the pump for the electrohydraulic actuators. The pump develops hydraulic oil pressure for operation of the air choke actuator and the wastegate actuator.The engine has an energize-to-run type of Gas Shutoff Valve (GSOV). When the programmable logic determines that fuel is required to start the engine, the ECM supplies +Battery voltage to the valve solenoid.At one second after the GSOV is energized, the pressure differential between the fuel and the air is monitored. The pressure is monitored to ensure that no fuel is entering the fuel manifold before the ECM issues a command to the fuel metering valve. If the differential pressure for fuel to air is less than 0.5 kPa (0.073 psi), the ECM supplies a command signal to open the fuel metering valve.The ECM controls the fuel metering valve by sending a PWM signal to control flow through the valve. During start-up, the combustion chambers are normally filled with excessive combustion air. The ECM operates the fuel metering valve to supply sufficient fuel for a combustible air/fuel mixture.The ECM removes the voltage from the starting motor solenoid when the programmable crank terminate speed is reached. The ECM also removes the voltage when a programmable cycle crank time has expired. The starter motor pinion disengages from the flywheel ring gear.The ECM removes +Battery voltage from the GSOV and commands the fuel metering valve closed. The fuel is shut off.The prelube system is programmed to perform a postlube cycle during engine shutdown. This supplies the turbocharger with adequate lubrication during shutdown. The post lube time is configurable in Cat ET.Engine Monitoring and Protection
The ECM monitors both the engine operation and the electronic system.Problems with engine operation cause the ECM to generate an event code. The ECM can issue a warning or a shutdown for events. The issuance depends on the severity of the condition.For example, a high-pressure pump provides hydraulic pressure with oil for the electrohydraulic system. The oil supply is separate from the engine oil. The