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:
Overhaul
Notice:
when using a vise, do not over tighten.
When installing, coat the parts indicated by the arrows with power
steering fluid .
1. Remove front wheel rh
2. Drain power steering fluid
3. Remove engine under cover rh
4. Remove fan and generator v belt
5. Disconnect oil reservoir to ...
Inspection procedure
1 Check p squib circuit(airbag sensor assy center – instrument
panel passenger airbag assy)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connector between the airbag sensor
assy center and the instrument panel ...
On–vehicle inspection
1. Inspect brake booster
Airtightness check.
Start the engine and stop it after 1 or 2 minutes. Depress
the brake pedal several times slowly.
Hint:
if the pedal goes down farthest at the 1st time, but gradually
rises after the 2nd or 3rd time, the booster is airtight.
...


