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
1 Inspect shift solenoid valve(sl)
Remove the shift solenoid valve sl.
measure the resistance according to the value(s) in the
table below.
Standard:
Connect the positive (+) battery lead to the solenoid connector
terminal, and the negative (–) battery lead to the
so ...
Replacement
Hint: components:
1. Precaution
2. Disconnect battery negative terminal
3. Remove instrument panel sub–assy lower
Remove the screw from the glove compartment door
stopper sub–assy.
pull the instrument panel sub–assy lower to remove it.
4. Separate passenger airbag co ...
Description
When troubleshooting obd ii vehicles, the only difference
from the usual troubleshooting procedure is that you
need to connect the vehicle to the obd ii scan tool complying
with sae j1978 or the hand–held tester, and read
various data output from the vehicle’s ecm.
Obd ii regulation ...


