A computer controls all these functions, lights, turn, hazard & brake lights, radio, a/c. If the Tire Pressure Low warning, and ABS & TRACTION warning symbols are lit, and you can't control windows and your accessories, the problem can be simple to correct. Using a diagnostic code scanner and diagnostic computer, run a full scan. If the Body Control Module communications failure error shows, the remedy goes like this: Take a look under the hood and locate a pigtail that is mounted on the passenger- side shock tower between the tower and the fuse box. It looks like an in-line fuse but twisting it in the usual manner doesn't give you a look at the innards. Push the connection untill you hear a distinctive "click." If you have the key in the ignition with switch "off" you should hear the " key in the ignition "warning . All other functions should now be on line.