My Dad has a 2002 f250 5.4 gas with 4x4. The problem he is expirencing is when he puts the engine under a load ( like when i go up a hill) the abs light come on and the speedometer goes crazy, then everything goes back to normal untill it happens again. He went to ford and of course they couldnt make it happen and no codes came up. However they suggested that it could be the rear abs/speedo sensor, so he had it replaced. Driving home there was no difference. Has anyone expirenced this problem, and or now how to fix it??