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
1 Check harness and connector(transmission control switch –
body ground)
Disconnect the transmission control switch connector of
shift lever assy.
measure the resistance according to the value(s) in the
table below.
Standard:
2 Inspect transmission control switch
M ...
Towing with a wheel-lift type truck
► From the front
Release the parking brake.
► From the rear
Use a towing dolly under the front wheels.
Vehicles without a smart key system: When not using a towing dolly, turn the
engine switch to the “ACC” position and shift the shift lever to N.
Vehicles with a smart key ...
Using the radio (Multimedia system)
Radio operation
Select “AM” or “FM” on the audio source selection screen to begin listening
to the radio.
Audio control screen
Pressing the “AUDIO” button displays the audio control screen from any screens
of the selected source.
1 Audio source selection screen appears
2 Preset ...


