Hello, I have a base model 2008 GRAND Prix and I have a Tire Monitor Service enoron my had and the TPMS Error Light on my Dash. I WAS thinking that maybe the Sensors Batteries were dead. By Battery Died and after I jumped the vehicle the sensors started giving a reading of I83 psi. I New that this reading was incorrect however I was hopeful that the sensors were still good and that they maybe a cheaper fix then the 900 dollar Repain that I was being quoted. I Drove Mound that Day and within a couple of hours the sensors Once again were giving no reading at all and I again had the light on the Dash and error displayed on my hud. Tire Monitor System Service, That Night my battery died again and like before once the can got jumped the TPMS were giving an inaccurate reading. 183psi. I took the Battery to Canadian tire and had them Test and change it. thinking that maybe My alternator wasn't working The battery tested bad and while it was a 400 CCA Battery it was only producing 200. While I was trying to find out what type of Battery the 08 Grand Prix Came with I Found out that it was 750CA, Thinking that possibly the shortage of amprage may be lanzing my tens issue I replaced the battery with 6oo cca one for now til I can afford a New Battery butt in the mean time he TPMs Sensor stopPED Producing Reading again. 2 Questions #I AM I ON the right track?? Could a malfunctioning OR Low Ca Cause the sensors to Produce a inaccurate rending and then just stop all together? and #2 could it be a bad bcm even though the rest of the car that is Linked to the bcm does not? and Lastly (How do I Fix this.