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 stop lamp switch assy
2 Check harness and connector(stop lamp switch assy – ecm)
Install the stop lamp switch assy.
disconnect the ecm connector.
measure the voltage according to the value(s) in the table
below when the brake pedal is depressed and rele ...
Circuit description
Refer to dtc p0120
Dtc no.
Dtc detection condition
Trouble area
P0121
The following condition is met 4 times. After the vehicle speed
has exceeded 19 mph (30 km/h) once, the throttle position
sensor output value is out of normal range when the throttle
...
Circuit description
The side squib (rh) circuit consists of the airbag sensor assy center and
front seat airbag assy (rh).
It causes the srs to deploy when the srs deployment conditions are satisfied.
Dtc b0110/43 is recorded when a short is detected in the side squib (rh)
circuit.
Wiring diagram
...


