Fuel Pump Control Circuit [09/2016 - 07/2020]: Description

When the engine is being cranked, the start request signal output from the hybrid vehicle control ECU is input to the ECM, and the NE signal generated by the crankshaft position sensor is also input to the ECM. Thus, the ECM interprets that the engine is being cranked, and turns an internal transistor on, causing current to flow to the C/OPN relay. The fuel pump then operates the NE signal is input into the ECM with the engine running, the ECM keeps the transistor on.