Toyota Corolla (E120): Ecm power source circuit
Other materials:
Rear view monitor system
The rear view monitor system assists the driver by displaying guide lines
and an image of the view behind the vehicle while backing up, for example while
parking.
The screen illustrations used in this text are intended as examples, and may
differ from the image that is actually displayed on t ...
How to proceed with troubleshooting
The hand–held tester can be used at step 4, 6, 8 and 9.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Warning light check
4 The dtcs check (present and past dtcs)
5 The dtcs chart
6 Circuit inspection
7 Repair
8 Clear the dtcs (present and past dtcs)
9 The dt ...
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 supplyin ...