My 2000 bravada will not shift into reverse or overdrive, and shifts hard from 1-2 gear. It won't shift from 1st to 2nd until about 3400 rpm. I have replaced the filter and fluid, which made the "service awd" light go out, but the shifting problem remains. I am thinking that it may be the control solenoid, but I am not sure where to find it. Any other ideas or tech data would be appreciated.