Toyota Corolla (E120): Circuit description
This is the power source of the ecu, hence the actuators.

Wiring diagram

Other materials:
On–vehicle inspection
1. Inspect cooling system for leaks
Caution:
to avoid the danger of being burned, do not remove the radiator
cap while the engine and radiator are still hot, as fluid
and steam can be blown out under pressure.
fill the radiator with coolant and attach a radiator cap tester.
  ...
Inspection procedure
1 Check door lock
2 Check wire harness (tvip ecu door lock)
Disconnect the tvip ecu and door lock connectors.
check the continuity between the terminals of the tvip
ecu and door lock connectors, as shown in the illustration
and table.
Standard:
3 Check wire harness ...
Steering wheel audio switches
Some audio features can be controlled using the switches on the steering wheel.
Operation may differ depending on the type of audio system or navigation system.
For details, refer to the manual provided with the audio system or navigation system.
Operating the audio system using the steering whe ...


