WARNING: This page is about a different car, the 2015 Lexus IS 250 and 2014 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.
CASE 1
Difference of main throttle position and sub throttle position
0.3 V or higher
CASE 2
Stop light switch signal (CPU) and stop light switch signal (Monitor IC)