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:
Circuit description
The camshaft position sensor (g22+ signal) consists of a magnet, iron core
and pickup coil.
The g22+ signal plate has 3 teeth on its outer circumference and is installed on
the camshaft timing pulley.
When the camshafts rotate, the protrusion on the signal plate and the air gap on
the pi ...
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 ...
How to proceed with troubleshooting
1 Vehicle brought to workshop
2 Customer problem analysis
3 Check and clear dtc
4 Problem symptom confirmation
5 Symptom simulation
6 Dtc check
7 Dtc chart
8 Problem symptoms table
9 Circuit inspection
10 Identification of problem
11 Parts inspection
12 Repair
1 ...