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:
Front passenger occupant classification system
Your vehicle is equipped with a front passenger occupant classification system.
This system detects the conditions of the front passenger seat and activates or
deactivates the devices for the front passenger.
1 SRS warning light
2 Seat belt reminder light
3 “AIR BAG OFF” indicator light ...
Inspection procedure
Hint:
read freeze frame data using the hand-held tester or the obd ii scan tool.
Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, it is
useful for determining whether
the vehicle was running or stopped, the engine was warmed up or not, the ...
On–vehicle inspection
1. Inspect brake booster
Airtightness check.
Start the engine and stop it after 1 or 2 minutes. Depress
the brake pedal several times slowly.
Hint:
if the pedal goes down farthest at the 1st time, but gradually
rises after the 2nd or 3rd time, the booster is airtight.
...


