Some 2007 Jeep Grand Cherokee SRT8 models with 6.1-liter "Hemi" engines and AWD systems may produce some rather strange electrical problems.
Among the complaints you might hear are that the front door module ceases to function, the radio mysteriously drops out and/or the AWD system won't engage. Furthermore, if you hook up your scanner you might find trouble code B210D (low battery voltage) or B210E (high battery voltage) logged in computer memory. Software issues in the PCM are the root cause of all the woes. Reprogramming the module with updated software is the only surefire remedy. Check with a dealer for the specifics of the flash.