The abs and traction actuator turns off the solenoids and the ecm shuts off vsc control (traction control signal) from the skid control ecu accordingly, the result being that it is as if the abs, trc and vsc systems were not installed.
If it is impossible to control the systems, the warning light comes on to inform the driver of malfunctions in the systems (see page bc-44).
Hint:

Freeze frame data
Data list / active testTrailer towing tips
Your vehicle will handle differently when towing a trailer. Help to avoid
an accident, death or serious injury, keep the following in mind when
towing:
Speed limits for towing a trailer vary by state or province. Do not
exceed the posted towing speed limit.
Toyota recommends that the vehic ...
Power steering ecu
Components
Removal
Disconnect cable from negative battery
terminal
Remove instrument panel sub-assembly
upper
Remove the instrument panel (see page ip-4).
Remove power steering ecu
Disconnect the 4 connectors.
Remove the 3 nuts and remove the power steering
e ...
Check mode procedure
Hint:
Intelligent tester only:
compared to normal mode, check mode is more sensitive to
malfunctions. Therefore, check mode can detect the
malfunctions that cannot be detected by normal mode.
Notice:
All the stored dtcs and freeze frame data are erased if:
The ecm is changed from normal mo ...