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
Hint:
if dtcs p0115, p0116, p0117, p0118 and p0125 are output
simultaneously, the engine coolant temperature
sensor circuit may be open or short. Perform the troubleshooting of dtc
p0115, p0117 or
p0118 first.
Read freeze frame data using the hand-held tester or the obd ii scan
to ...
For your information
Main Owner’s Manual
Please note that this manual applies to all models and explains all equipment,
including options. Therefore, you may find some explanations for equipment not installed
on your vehicle.
All specifications provided in this manual are current at the time of printing.
Howeve ...
Inspection procedure
Hint:
start the inspection from step 1 in case of using the hand–held tester and start
from step 2 in case of not
using the hand–held tester.
1 Read value of hand–held tester(front speed sensor)
Select the datalist mode on the hand–held tester.
check that there is no differe ...