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

Wiring diagram

Other materials:
Circuit description
If the engine coolant temperature (ect) does not reach 75°c (167°f) despite
sufficient warm – up time has
elapsed.
Dtc no
Dtc detection condition
Trouble area
P0128
Condition (a), (b) and (c):
cold start
after engine is warmed up
& ...
Diagnostics
Preparation
Sst
09816–30010
Oil pressure switch socket
Sfi system
09843–18040
Diagnosis check wire no.2
Sfi system
supplemental restraint
system
Recomended tools
09082–00040
Toyota electrical tester
Sfi system
supplemen ...
Circuit description
The ignition switch provides circuit power and the ecm provides the circuit
ground that illuminates the mil.
Mil operation is checked visually:
it should be illuminated when the ignition is first turned on. If the mil is off
all of the time or on all of the time,
use the procedure below to ...


