Service park assist

[Savsnnah]

Hello!
I keep getting service park assist pop up. When I put my car in reverse my backup camera is showing red for all four of my back sensors. Any suggestions on what I should start with replacing?
2015 Tahoe LT

 

[swathdiver]

Don't throw parts at it. Get a scan tool that can read chassis and BCM codes. On the previous generation, the lines for the camera reside in the steering wheel angle sensor.