2008 Escalade ESV. On the dash, I noticed my passenger front tire pressure was going crazy over the weekend. From 1 PSI to 70 PSI. The numbers were jumping all over the place. Now, it seems to be holding at 7 PSI, even though all the tires are at 35. I am getting a tire pressure warning light as a result. Is there something I can do to troubleshoot this particular sensor? Is there wiring that could be bad, or is this the sign of a worn out sensor? I'm not the original owner, so I don't know how old the sensors are. I tried going through the relearning process, but when I get to the passenger front, it does not seem to register. Any insight is appreciated. Thanks!