My VCS, Trac off and check engine light just came on. What is usually the cause for this? Please let me know.

Did you make any mods?

no mods

Alternator or Battery I believe. Think this has been mentioned before...

OK after a little searching here's what I came up with:

http://www.scionlife.com/forums/viewtopic.php?t=67944&highlight=vcs+trac+lights

http://www.scionlife.com/forums/viewtopic.php?t=67925&highlight=vcs+trac+lights

http://www.scionlife.com/forums/viewtopic.php?t=11001&highlight=vcs+trac+lights

http://www.scionlife.com/forums/viewtopic.php?t=11767

Not very conclusive. Looks like it could be a multitude of things....Very interesting.