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
1. Charcoal canister assy
Visually check the charcoal canister for cracks or damage.
Inspect the charcoal canister operation.
Plug the vent port with the cap.
While holding the purge port closed, blow air (1.76
Kpa, 18 gf/cm2, 0.26 Psi) into the evap port and
...
Circuit description
A thermistor is built in the engine coolant temperature sensor and changes
the resistance value according
to the engine coolant temperature.
The structure of the sensor and connection to the ecm is the same as those of
the intake air temperature
sensor.
Hint:
if the ecm detects the dtc ...
SRS airbags
The SRS airbags inflate when the vehicle is subjected to certain types of
severe impacts that may cause significant injury to the occupants. They work together
with the seat belts to help reduce the risk of death or serious injury.
◆ SRS front airbags
1 SRS driver airbag/front passenge ...