Toyota Corolla (E120): Circuit description
This is the power source of the ecu, hence the actuators.

Wiring diagram

Other materials:
Circuit description
Refer to dtc p0115
Dtc no.
Dtc detection condition
Trouble area
P0125
If the engine coolant temperature (ect) was less than –6.6 °C
(20 °F) when starting the engine, and 20 minutes after the engine
start, the ect sensor still indicates below 20 °C (68 ...
Engine immobilizer system
The vehicle's keys have
built-in transponder chips
that prevent the engine from
starting if a key has not
been previously registered
in the vehicle's on-board
computer.
Never leave the keys inside
the vehicle when you leave
the vehicle.
This system is designed to
help prevent vehicle theft
but doe ...
Deactivating or stopping the alarm
Do one of the following to deactivate or stop the alarm:
● Unlock the doors or open the trunk.
● Vehicles without a smart key system:
Turn the engine switch to the “ACC” or “ON” position, or start the engine. (The
alarm will be deactivated or stopped after a few seconds.)
& ...


