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:
Display and menu icons
■ Display
Driving support system status
display area
Displays an image when the following
systems are operating and a
menu icon other than is
selected:
LTA (Lane Tracing Assist)
LDA (Lane Departure Alert)
Dynamic radar cruise control
RSA (Road Sign Assist) (if
equipped)
Content disp ...
Symptom confirmation and diagnostic trouble code
Hint:
the diagnostic system in corolla has various functions. The first
function is the diagnostic trouble
code (dtc) check, in which a malfunction in the signal circuits to the ecu
is stored in code form in
the ecu memory. Another function is the input signal check, which checks if
...
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 the hand–held tester.
1 Perform active test by hand–held tester(abs motor relay)
Check the operation sound of the abs motor individually when operaing it
with the ...


