So guys my gf's 97 cavalier has had a coolant temp sensor issue for awhile that I am now getting around to having time to work with. Long story short, the coolant temp gauge shows no temperature, there's a cel for high voltage to the Coolant temp sensor. I have replaced the sensor with three different brand new sensors, cleared the code, same deal no temp showing on the gauge and the code comes right back. So I replaced the pig tail on the sensor, and metered the voltage coming to the pig tail and it was all within spec. Haynes (It may be another brand will have to ask her grandfather though) manual, plus googling shows this to be an issue that requires replacing the ECM. Now I have found ECM's at Autozone for less than $100. My question is, think this may fix this as well as are there any known issues with new ECM's for this car? I know this has to be preprogrammed and Autozone said that they will need the vin so the manufacturer can reprogram this. So what do you guys think?