WARNING: This page is about a different car, the 2009 Lexus IS 350 and 2009 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.
DTC Code
DTC Detection Condition
Trouble Area
C1428
With the ABS motor relay OFF and the ABS motor fail safe relay ON, an open in the motor circuit continues for 2 seconds or more.