Disconnecting the battery on a 2005 Jeep Grand Cherokee 4.7L will likely cause the radio to require a code to be re-entered, and may reset some other settings like the clock and possibly the seat positions. However, it
should not require a full computer reprogramming. The computer's main settings and programming are generally stored in non-volatile memory that retains data even without power.
While some minor settings might be lost, the engine control module (ECM) and other crucial computer systems should retain their programming. If there are any issues, they are usually minor and easily reset.
