Toyota Corolla (E120): Check and replace ecu
Notice
: start an inspection of the connector from the backside of the connector on the wire harness side with the connector connected to the ecu.
When no measurement condition is specified, perform the inspection with the engine stopped and also the ignition switch on.
- First check the ecu ground circuit. If it is faulty, repair it.
If it is normal, the ecu could be faulty. In this case, replace the ecu with one that functions normally and check if the symptoms appear.
- Measure the resistance between the ecu ground
terminal and body ground.
Resistance: 1 Ω or less

- Disconnect the ecu connector, check the ground terminals on the ecu side and wire harness side for bends and check the contact pressure.

Other materials:
Switches
Instrument panel light control dial
Automatic High Beam switch
Heated steering wheel switch*
Windshield wiper de-icer switch*
Outside rear view mirror switch
Door lock switches
Power window switches
Window lock switch
*: If equipped
Meter control switches
Paddle shift switches*1
C ...
Glossary of sae and toyota terms
This glossary lists all sae–j1930 terms and abbreviations used in this manual
in compliance with sae recommendations,
as well as their toyota equivalents.
...
PCS (Pre-Collision System)
The pre-collision system
uses sensors to detect
objects in the path
of the vehicle. When the
system determines that the
possibility of a frontal collision
with a detectable
object is high, a warning
operates to urge the driver
to take evasive action and
the potential brake pressure
is increased to h ...


