I don't have a lot of time to type before heading out to work. You'll have to research some of this your self. On this forum I found someone who had posted a link to a Facebook page for Jeeps. I went to the page and posted a comment about how I totally expected this post to be taken down but I was not happy with my Commander and the safety recall...yada, yada, yada "service 4WD system" yada, yada, yada no 4wd low. Within 2 days a lady commented back to me wanting to know my contact info and VIN of the Commander. I sent the info to her and within a couple of days a man from Chrysler called me and gave me his info and asked that I schedule the jeep with a dealer and have them redo the safety recall and then email him back with where I was taking it and when the appointment was. He said that he would talk to the service manager and then a Chrysler tech would be on the phone with the dealer tech when the recall was done to assure that it was done right. He also said that if the actuator motor that engages the "LO" was bad that they would replace it under warranty also. Took the Commander to the dealer today, wiped out all the codes, redid the recall and lo and behold the transfer would not go into "LO". They checked the wiring harness and there was a signal to the actuator but it was not working. Actuator motor on order with a 2 day delivery projection. Gotta run but I hope this helps some of you with this "service 4WD system" problem. God bless All Y'all.