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:
Circuit description
The park/neutral position switch detects the shift lever position and sends
signals to the ecm.
Monitor description
The park/neutral position switch detects the gearshift position and sends a
signal to the ecm.
For security, the park/neutral position switch detects the gearshift positio ...
Inspection procedure
1 Inspect shift solenoid valve(s1)
Remove the shift solenoid valve s1.
measure the resistance according to the value(s) in the
table below.
Standard:
Connect the positive (+) battery lead to the solenoid connector
terminal, and the negative (–) battery lead to the
solenoid ...
Ecu power source circuit
Circuit description
This circuit provides power to operate the tvip ecu.
Wiring diagram
Inspection procedure
1 Check fuse (ecu–b)
Remove the fuse from the instrument panel j/b.
check the continuity of the fuse.
Standard: continuity
2 Check tvip ecu
Disconnect ...


