The ABS light comes on in my 2003 Chevy Cavalier (manual) whenever I put the car in reverse. It seems to do this more when it is warm outside >80*F. All I need to do is put the car in 1st gear, turn off the engine, and restart. Any reason why this is happening and how to fix it w/o going to an expensive mechanic?
Check the brakes to make sure there are no serious problems. If OK, try cleaning the sensors. Very carefully pull the sensor connections off and check for dirt, bugs etc. Gently blow some air through and put the connectors back on. I have the same problem with a Skylark, the ABS will clear if the engine is turned off then back on. A simple cleaning makes it go away for months.
Check your brake fluid first. A lot less work to top it off.