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
When a misfire occurs in the engine, hydrocarbons (hc) enter the exhaust in
high concentrations. If this hc
concentration is high enough, there could be an increase in exhaust emissions
levels. High concentrations
of hc passing through the catalyst also cause to temperature of the catalyst to ...
Replacement
Hint:
installation is in the reverse order of the removal. But the installation is
indicated only when it has a point.
1. Remove radiator grille sub–assy
Remove the 2 bolts and clip.
using a screwdriver, remove the radiator grille.
Hint:
tape the screwdriver tip before use. ...
Replacement
1. Remove radiator grille sub–assy
2. Remove front bumper cover
3. Remove fog lamp assy lh
Remove a nut and release a claw.
remove the fog light assy lh.
4. Put vehicle these conditions
5. Adjust fog light aim
6. Check fog light aim ...


