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:
On–vehicle inspection
1. Inspection throttle body idle speed control valve assy
Notice:
it is impossible to check the resister value and the operation
of isc valve by itself, because the isc valve
has an ic circuit inside it, which transforms the duty
signal from the ecm to the derive signal.
After check ...
Overhaul
1. Remove generator pulley
Sst 09820–63010 (09820–06010, 09820–06020)
Hint:
Hold sst 1 – a with a torque wrench, and tighten sst 1
– b clockwise to the specified torque.
Torque: 39 nvm (398 Kgf·cm, 29 ft·lbf)
Notice:
check that sst is secured to the rotor shaft.
...
Headlamp dimmer switch assy
Replacement
1. Remove steering column cover lwr
Remove 3 screws and steering column cover lwr.
2. Remove headlamp dimmer switch assy
Disconnect the connector.
release the claw and pull out the head light dimmer
switch assy.
...


