Parking Sensor Error

[Rodbourne87]

Hi All,

I backed into a low post fairly hard and the post hit between two parking sensors and my sensors stopped working.
On removal of the bumper, the wires from the rear centre left sensor were sliced on impact. First of all, the mechanic at work soldered the wires, put heat shrink connectors on them and they still wouldn't work. They would flash up for a couple of seconds and then the fault would come up "No park assist, please park unaided"
My brother then said that the solder may have changed the resistance so we cut the soldered part off and just re-attached the wires using the heat shrink connectors. They worked for 5 seconds or so and then the fault comes up again. There is no damage to any other part of the parking sensors. We changed the sensor and the same fault came up so it's not that. The actual fault code on the reader is 803211.
We have changed the sensor and it still doesn't work so I'm convinced it's the wiring but not sure what else could be causing the issue.