Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Ecm power source circuit / Circuit description
Toyota Corolla (E120): Circuit description
When the ignition switch is turned on, battery positive voltage is applied to the coilwhich closes the contacts of the efi main relay (marked: efi) and supplies power to terminal +b of the ecm.
This signal causes current to flow to the coil, closing the contacts of the efi relay and supplying power to terminal +b of the ecm.
If the ignition switch is turned off, the ecm continues to switch on the efi relay for a maximum of 2 seconds for the initial setting of the isc valve.
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 ...
On–vehicle inspection
1. Inspection throttle body idle speed control valve assy
Notice:
it is impossible to check the resister value and the operation
of isc valve by itself, because the isc valve
has an ic circuit inside it, which transforms the duty
signal from the ecm to the derive signal.
After check ...
PDA (Proactive driving assist)
When a detectable object
is detected, the
proactive driving assist
operates the brakes and
steering wheel to help prevent
the vehicle from
approaching too close to
the object.
WARNING
■For safe use
Driving safely is solely the responsibility
of the driver.
The proactive driving assist is
design ...