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:
Problem symptoms table
Hint:
proceed with troubleshooting of each circuit in the table below.
Symptom
Suspect area
When the ignition switch is in the on position, the srs warning
light sometimes comes on after approximately 6 seconds.
Srs warning light ci ...
RSA (Road Sign Assist)
The RSA system detects
specific road signs using
the front camera and/or navigation
system (when speed
limit information is available)
and warns the driver
via displays and buzzers.
WARNING
■For safe use
Driving safely is solely the
responsibility of the driver. Pay
careful attention to the su ...
Circuit description
The shift solenoid valve sl is turned ”on” and ”off” by signals from the ecm
in order to control the hydraulic
pressure operation, the lock–up relay valve, which then the controls operation
of the lock–up clutch.
Fail safe function:
if the ecm detects a malfunction, it turns the ...