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:
How to proceed with troubleshooting
1 Vehicle brought to workshop
2 Customer problem analysis
3 Check and clear dtcs and freeze frame data
4 Problem symptom confirmation
Symptom does not occur: go to
step 5
Symptom occurs: go to step 6
5 Symptom simulation
6 Dtc check
There is no
output: go to step 7
There is outp ...
Using a flat bed truck
If you use chains or cables to tie down your vehicle, the angles shaded in black
must be 45°.
Do not overly tighten the tie downs or the vehicle may be damaged.
■Before emergency towing
1 Vehicles without a smart key system: Put the engine switch in the “ACC” (engine
off) or “O ...
Key confinement prevention function does not work
properly (unlock warning switch circuit)
Circuit description
The unlock warning switch turns on when the key is inserted in the ignition
key cylinder and the door courtesy
switch turns on when the driver’s door is opened, and the integration relay
monitors both switches conditions.
According to these switches conditions, the int ...