*While driving vehicle on highway heard a loud noise and grinding sound and PTU exploded and *was not able to maneuver vehicle properly. *Fluid that was leaking out . Caused fire . Once car turned off this stopped flames .This could have been a very dangerous situation if it had not gone out for us and others on the highway. * we brought the vehicle to our mechanic who diagnosed it and said there was a problem to bring it to the Jeep dealer who also diagnosed the same problem. * it is currently still at the Jeep dealer . Because there are no parts available, which makes us wonder if this has happened to many other people.. * there were no warning, lamps or messages that came on.