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:
How to proceed with troubleshooting
1 Vehicle brought in
2 Customer problem analysis check and symptom check
3 Problem symptoms table
Without applicable symptoms, proceed to ”a”
with applicable symptoms, proceed to ”b”
4 Perform troubleshooting in the following method, depending on
malfunction symptom ...
Cd sound skips
Inspection procedure
1 Disc cleaning
Disk cleaning
) if the disk gets dirty, clean the disk by wiping the surface
from the center to outside in the radial directions
with a soft cloth.
Notice:
do not use a conventional record cleaner or anti–static preservative.
Standard: ...
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)]
...


