PDC problem

[PersonaNonGrata]

I've read all of the PDC problem threads and never though it would happen to me but it did. I felt like since I did the installation myself it would be trouble free.

Symptoms:

When I put it in reverse, the PDC turns on and the front speaker emits a long beep even when there is no object in front. The PDC light flashes. The rear sensors do not detect anything.

Troubleshooting attempted:

I checked all of the sensors and they are wired up. There are no scratches or dirt on the sensors. All sensors are in place. I removed the control unit and inspected it. No problems with the unit itself and I replugged in the plugs. I checked the connection of the wiring harness for the rear sensors and the harness inside the spare tire well. All good there.

I am thinking it might be the control unit itself. I have read that it has been the source of problems. I'd love to swap out my control unit with someone elses to confirm or eliminate it as the problem but I don't know anyone with PDC on their X5. Has anyone experienced the same symptoms?