OneHundred80 and anyone else who can help with advice....
Same issue as above except I have learned a little more.
My car would not start, it was towed to an independent shop. The shop ordered 5099541-AAModule DO 08035031 from Chrysler. They also ordered 168-464-02-53 Transponder from Mercedes-Benz.

My car key was towed in with the car. Mechanic said he needed both keys so he could program them. My key would NOT take the program and is virtually useless at this point. The spare key will start/run and unlock the doors. It will not lock any doors. I have no working alarm system. Air bag light was on.

Took the car to Chrysler. They put a diagnostic tests on it. Determined my battery was low so I now have a new battery. The air bag light is off but they could not program the keys. Same state as before. My key is still useless and the spare key will run the car. I manually lock the passenger door (push button down). I insert spare key in drivers side door to lock and the hatch is never locked.

I took my XF to an Independent Mercedes-Benz dealer. He listened to my story, assured me my keys were a Mercedes=Benz item and that he could not replace them due to 'coding' them with my VIN # (for theft reasons). He gave me the number to a Mercedes-Benz dealer in Palo Alto.

I called spoke to John. He told me they could not help me, could not order parts because my VIN # is a Chrysler number. I told him the car is 80% Mercedes-Benz and that a reg mechanic shop ordered from Mercedes-Benz but in SF. Said he was sorry but that I had to take it back to Chrysler.

Chrysler is at a loss as to why my keys will not reprogram and wants me to order new keys at $350. each. There is o guarantee this will fix my problem.

My question to you....from your XF experience do you think this will fix my problem. Will new keys work no matter what?? Also is there a way on this forum where I can find SF Bay Area (CA) XF owners to connect with them to find out where they take their car for problems.

Thank you for all your help.
Sandy