about the ecm module on 1996 Pontiac Sunfire

i own 1996 pontiac sunfire gt i put a new ecm module in it now it doesnt want to change gears an the speed omiter doesnt work what would make it do that

Asked by for the 1996 Pontiac Sunfire
The ecm and speedometer need vehicle speed sensor input to operate. Is there a Check Engine Light on? If so a scan tool will retrieve codes identifying what area the fault is in. If you are trouble shooting this yourself there are two companies that independent auto repair shops "buy" their information from that offer a very reasonable service to do it yourselvers. You can get a one week subscription or year subscription very cheap. The information is year make and model specific repair procedures, service bulletins, component locations, wiring diagrams ect.... great quality information same as the professionals have,much better than generic workshop manuals from parts stores and much cheaper than the factory manual try Alldata which is very easy to navigate or Mitchell on line and get an online repair manual subscription.
I have a 1996 Sunfire also (2.2) and mines acting very similar..Replaced ECM and now my speedos going crazy! It says Im doing about 40 right from take off and the trans is shifting through the gears way too fast..Im in 3rd by the time I hit 30 but the speedo says Im doing about 80?! Please keep me posted as to what u find out and ill do the same..