With all the confusion on how the many different traction systems alphabet soup work, I did some research and figured I'd throw this together.
Trac- Cuts power and brakes spinning wheel(s). “Traction Control”
VSC- Controls spins by braking select wheels. “Stability Control”
AutoLSD- Brakes spinning wheels to emulate LSD- does not cut power. Avail only in 2WD mode.
ATRAC- Avail only on OR models. Similar ALSD operation except available in 4WD mode.
When you start an 09 Tacoma:
When wheels spin, cuts power and brakes spinning wheel. If slide is detected, “beep beep beep” and slide is corrected.
Quick push of button:
Trac- limited op (see below)
When wheel spins, brakes spinning wheel but does not cut power (ALSD function). If slide is detected, “beep beep beep” etc. Will only brake select wheels to control spin when spin is detected.
Hold down button while stopped:
When wheel spins, it will keep spinning. No slide corrections under 30 mph. ie, used for donuts, etc. VSC is always enabled over 30 mph.
ATRAC- Only on OR models. Provides “AutoLSD” in 4WD mode (braking spinning wheels but not cutting power).
In 4WD mode (ex OR), only disable feature is VSC by holding button down (no ALSD), but again activates over 30mph.