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:
Inspection procedure
Hint:
if different dtcs related to different systems that have terminal e2
as the ground terminal are output
simultaneously, terminal e2 may be open.
Read freeze frame data using the hand-held tester or the obd ii scan
tool. Freeze frame data records
the engine conditions when a malf ...
Check open circuit
For the open circuit in the wire harness in fig. 1, Perform
a resistance check in step (b) or a voltage check in step
(c) to locate the section.
Check the resistance.
Disconnect connectors a and c and measure the
resistance between them.
Resistance: 1 Ω or les ...
Cleaning and protecting the vehicle exterior
Perform the following to protect the vehicle and maintain it in prime condition:
● Working from top to bottom, liberally apply water to the vehicle body, wheel
wells and underside of the vehicle to remove any dirt and dust.
● Wash the vehicle body using a sponge or soft cloth, such a ...


