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:
Wheels
If a wheel is bent, cracked or
heavily corroded, it should
be replaced. Otherwise, the
tire may separate from the
wheel or cause a loss of
handling control.
Wheel selection
When replacing wheels, care
should be taken to ensure that
they are equivalent to those
removed in load capacity, diameter,
rim ...
Warning buzzer does not sound (key reminder
warning, light reminder warning)
Wiring diagram
Inspection procedere
1 Check buzzer
Check that all of the warning buzzers sound.
2 Inspect front door courtesy lamp switch assy
3 Inspect un–lock warning switch assy
4 Check harness and connector(between un–lock warning switch
and combination meter as ...
Inspection procedure
1 Inspect terminal voltage(od – body ground)
Disconnect the cruise control ecu connector.
turn the ignition switch to the on position.
measure the voltage between terminal od of cruise control
ecu and body ground.
Standard:
2 Inspect terminal voltage(od1 – bod ...


