Cadillac Repair: cadillac sensors, cadillac sedan deville, pcm data

Question
I have a 96 cadillac sedan deville,lately some sensors have been coming on. The car has 86000 miles.The sensor that came on was a speed sensor, the speedometer stayed on zero and the tranny stayed in 1st gear.The service engine light stayed on until I disconnected the battery for about 5 minutes the light went out. I was told the computer had to be reset.The other fault was emission sensor,I had it replaced at a cost of $300 later the light came on again same fault can I reset the computer myself? and how do I do it?            Thanks for any help  

Answer
Hi Vern, Yes you can reset the computor or clear the codes yourself but if the same code came back then the shop that did the diagnosis owes you a refund or you have other problems other than that part. If the problem isn't fixed you will be clearing the codes every other time you drive your car. To clear the codes run the engine in park and push off and warmer buttons on the climate control panel for 5 seconds or until it goes into diagnostics. It will dislay all the codes and then display PCM?...at that point push hi fan. Now it sould show PCM DATA?...keep pushing lo fan until it shows clear codes?...then push hi fan and the codes should clear. To exit out of diagnostics turn the key off and the next time the engine is started the display will return to normal. Hope that makes sense. Bill