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:
Setting the tire pressure
(vehicles with a tire pressure
warning system)
In the following situations, it will
be necessary to perform the tire
inflation pressure setting procedure
of the tire pressure warning
system.
When the specified tire inflation
pressure has changed,
such as due to carried load,
etc.
When the tire inflation pressure
is changed such as
when t ...
Inspection procedure
Hint:
start the inspection from step 1 in case of using the hand–held tester and start
from step 2 in case of not
using hand–held tester.
1 Inspect brake actuator assy
Select the datalist mode on the hand–held tester.
check the operation sound of the abs pump motor when operat ...
Circuit description
The o/d main switch (transmission control switch) is a momentary type switch.
When pressing the o/d main
switch, the o/d off indicator light lights up and the ecm prohibits shifting
into o/d, and when pressing it
once again, the o/d off indicator light goes off and the ecm allows shifting
in ...


