Remote Keyless Entry Issue

[X53Jay4.8is]

Okay so a couple of weeks ago the remote keyless entry stopped working on the X5. The central lock system still works just fine and the keys are transmitting just fine. All fuses are good. I checked the rear amplifier antenna on the real tailgate and the three wires that go into it are red, purple and yellow/white. There is 12 volts on the red all the time, the purple/white is energized with 12volts when the ignition comes on but the yellow/white has nothing. I saw on you tube where a tech had hooked up a labscope to the 3 wires that I referenced and it shows that the yellow/white wire should have a 12volts coming through it. I check my wires at the tailgate and see no breakage on the yellow/white wire. In the bentley manual on( page 600-9) they mention the vehicle has a keyless entry remote module (FBZV). has anyone heard of the FBZV module and where is it located on the X5? Stumped!!!