2015 GMC Sierra 1500 crew cab SLT

[manuel pasillas]

My 2015 GMC Sierra 1500 ,I have this message SERVICE PARK ASSIST 
SISTEM And I replace all rear sensors and wire harness and still have the same 
message if anyone know a quick solution will be highly appreciate it thanks in 
advance

[Boewing1]

Our 2016 Cadillac had same issue, was the ground wire on the vibrating seat.

[Steveo553]

I had the same issue on my truck.  The drivers seat has a left and right side vibrating sensor.  The left one commonly goes out causing the warning light to activate.  Apparently the wire breaks over time due to getting in and out of the truck.  Park close to something to cause the vibrating warning to occur and feel which sensor is not working.  The dealer replaced it under warranty.  They had to take the cover off and they replaced the sensor.