Mut-II Cannot Communicate With Other Systems
WARNING: This page is about a different car, the 1995 Mitsubishi Eclipse, 1995 Eagle Talon, 1995 Dodge Avenger, and 1995 Chrysler Sebring. However, it is still accessible from the selected car via links, so may be relevant.
Check for faulty power or ground circuit to DLC. If power and ground circuits are okay, MUT-II is faulty.