Re: ACC/FCW Unavailable
Actually, the part might fix the problem. I've heard of several cases where the missing bezel makes the radar think the sensor is dirty.. my guess is that the bezel interacts with the beam, possibly keeping sidelobes from sensing the discontinuity at the front of the bezel.
68143107AB, $11.24 at east coast moparts.
If that doesn't fix it, then have the dealer look at it. My bet is that if you show up with the bezel missing, they will claim damage and not warranty any work on the sensor (that's what happened in one of the cases mentioned above).
2007 WK Limited 5.7L
2014 WK2 Overland 5.7L
And a few past Durangos