I drive a 2007 Toyota RAV4 with 54K. At random times (possibly associated with cold weather), the 4WD warning light blinks and then stays on followed by the VSC, Brake, and ABS lights. These will stay on for a time and then turn off spontaneously. I have had this problem twice before and have had the right rear speed sensor cleaned ($100) and the left rear speed sensor replaced($500). One year later the probolem is recurring. Health codes I have recieved in the past were C0125 C1223 and C1238. Now there are no codes. How can I fix this permanently?