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:
Using the interior lights
Interior lights list
1 Front interior light/personal lights
2 Rear interior light
3 Engine switch light (vehicles with a smart key system)
Front interior light/personal lights
■ Front interior light
► Type A
► Type B
1 Off
2 Door position
3 On
■ Personal li ...
System description
The ecm uses the signals from the throttle position sensor, air–flow meter
and crankshaft position sensor
to monitor the engagement condition of the lock–up clutch.
Then the ecm compares the engagement condition of the lock–up clutch with the
lock–up schedule in the
ecm memory to de ...
Basic inspection
Resistance measuring condition of electronic parts
unless stated, all resistance is measured at an ambient
temperature of 20 c (68 °F). As the resistance
may be outside the specifications if measured at high temperatures
immediately after
the vehicle has been running, measu ...


