Abs light comes on when parked and then goes out

There is a grounding strap behind the framerail, just below the front of the driver side door, check to see if it is corroded. if there is a bad ground, or no ground the indicators sometimes start to do funny things. I had a similar issue with my truck. all you should have to do is reattach the ground strap to the frame, and put some grease on it to prevent future corrosion. I hope this fixes your problem cheap and easily