Fuel Pump Control Circuit [01/2019 - 11/2022]: Description

WARNING: This page is about a different car, the 2022 Toyota Corolla, 2021 Toyota Corolla, 2020 Toyota Corolla, and 2019 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

When the engine is cranked, the ST relay drive signal output from the ignition or starter 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 crank 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 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