Many technicians are familiar with the problem of early shift scheduling on the 4L80-E transmission. This prob¬lem is caused by a 4×4 low range signal being sent to the computer at an inappropriate time. Vehicles equipped with the E4OD/4R100 transmission may also have this type of problem. A code 47/633 is usually your first clue in identifying this condition. Since Ford uses the same wiring harness in both 4-wheel drive and 2-wheel drive vehicles, you may find code 47/633 in both types of vehicles.