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:
Engine oil
With the engine at operating temperature and turned off, check the oil level
on the dipstick.
■ Checking the engine oil
1 Park the vehicle on level ground. After warming up the engine and turning it
off, wait more than 5 minutes for the oil to drain back into the bottom of the engine.
2 ...
Replacement
Hint: components:
1. Precaution
2. Disconnect battery negative terminal
3. Remove horn button assy
Place the front wheels facing straight ahead.
using a torx socket wrench (t30), loosen the 2 torx
screws until the groove along the screw circumference
catches on the screw ca ...
Inspection
1. Power window system circuit
2. Inspect power window regulator master switch assy
Inspect the master switch continuity.
[Driver’s switch (window unlock and lock)]
Standard:
[Front passenger’s switch (window unlock)]
standard:
[Front passenger’s switch (window lock)]
...


