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:
Inspection procedure
Hint:
read freeze frame data using the hand-held tester or the obd ii scan tool.
Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, it is
useful for determining whether
the vehicle was running or stopped, the engine was warmed up or not, the ...
Inspection procedure
1 Check wire harness(dlc3 – airbag sensor assy center)
Turn the ignition switch to the lock position.
disconnect the aribag sensor assy center connector.
measure the resistance according to the value(s) in the
table below.
Standard:
2 Check wire harness(cg of dl ...
Switches
Instrument panel light control dial
Automatic High Beam switch
Heated steering wheel switch*
Windshield wiper de-icer switch*
Outside rear view mirror switch
Door lock switches
Power window switches
Window lock switch
*: If equipped
Meter control switches
Paddle shift switches*1
C ...


