Fuel Pump Control Circuit [08/2013 - ]: Description

When the engine is cranked, the starter (ST NO. 1) relay drive signal output from the ignition switch assembly*1 or certification ECU (smart key ECU assembly)*2 is input into the STA terminal of the ECM, and the NE signal generated by the crankshaft position sensor is also input into the NE+ terminal. The ECM interprets that the engine is cranked, and turns transistor Tr1 in the ECM internal circuit on. Current flows to the C/OPN (Circuit Opening) relay by turning Tr1 on. Then, the fuel pump operates.

While the NE signal is input into the ECM with the engine running, the ECM turns Tr1 on continuously.

*1: w/o smart key system.

*2: w/ smart key system.