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:
Overhaul
Caution:
wear the gloves, because the cutting surface of the seat back frame and seat
adjuster may injure
your hand.
Hint:
tape the screwdriver tip before use when prying parts.
1. Disconnect battery negative terminal
Caution:
wait for 90 seconds after disconnecting the battery terminal a ...
Problem symptoms table
Hint:
proceed with troubleshooting of each circuit in the table below.
Symptom
Suspect area
When the ignition switch is in the on position, the srs warning
light sometimes comes on after approximately 6 seconds.
Srs warning light ci ...
Inspection procedure
1 Check source voltage
Measure the voltage of the battery.
Ok:
voltage: 10 – 14 v
2 Check air bag sensor assy center
Disconnect the negative (–) terminal cable from the battery, and wait at
least for 90 seconds.
disconnect the connectors from the airbag sensor assy ...


