Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Fuel pump control circuit / Circuit description
Toyota Corolla (E120): Circuit description
In the diagram below, when the engine is cranked, current flows from terminal st2 of the ignition switch to the starter relay coil and also current flows to terminal sta of the ecm (sta signal).
When the sta signal and ne signal are input to the ecm, tr is turned on, current flows to the coil of the circuit opening relay, the relay switches on, power is supplied to the fuel pump and the fuel pump operates.
While the ne signal is generated (engine running), the ecm keeps tr on (circuit opening relay on) and the fuel pump also keeps operating.

Wiring diagram

Other materials:
Seat heaters
Press the switch.
1 High temperature
2 Low temperature
The indicator light comes on when the switch is on.
■The seat heaters can be used when
► Vehicles without a smart key system
The engine switch is in the “ON” position.
►Vehicles with a smart key system
The engine ...
Circuit description
While driving uphill with cruise control activated, in order to minimize gear
shifting and provide smooth cruising
overdrive may be prohibited temporarily under some conditions.
The cruise control ecu sends o/d cut signals to the ecm as necessary and the ecm
cancels overdrive
shifting until ...


