Electrical problems. Transmission problems.

Hello, it would be quite helpful to know which engine and transmission your Bronco has. It could be one of 3 -- and only one is electronically operated. It makes the answer different. This vehicle utilizes a speedometer cable for operation of the speedometer. Therefore, a "vehicle speed sensor" does not play a part in speedometer operation. The check engine light will not have anything to do with transmission operation or shifting hard, more than likely. Testing is required to find out details of what codes are being set, though, which will most likely be related to engine performance. The exception would be if there is an E4OD transmission equipped with your Bronco. Codes could be present for that. If you have an AOD automatic transmission, you could have a detached throttle valve (TV) cable. This causes all kinds of automatic transmission problems and can actually inspire transmission failure. All because of a cheap little grommet detaching at the throttle. Inspect this.