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:
Starting the engine
► Automatic transmission or continuously
variable transmission
1 Check that the parking brake is set.
2 Check that the shift lever is set in P.
3 Firmly depress the brake pedal.
4 Turn the engine switch to the “START” position and start the engine.
► Manual transmission
1 Che ...
Inspection procedure
1 Check harness and connector(transmission control switch –
body ground)
Disconnect the transmission control switch connector of
shift lever assy.
measure the resistance according to the value(s) in the
table below.
Standard:
2 Inspect transmission control switch
M ...
Inspection procedure
Hint:
hand–held tester only:
narrowing down the trouble area is possible by performing ”a/f control” active
test (heated oxygen
sensor or other trouble areas can be distinguished).
Perform active test using hand–held tester (a/f control).
Hint:
”a/f control” is the active te ...