I am having some issues with my parksense system on my 2012 grand cherokee altitude. it only has the sensors in the back and there is no park assist. when i got the truck, the rear bumper had been stolen. i ordered the bumper, 4 sensors and the harness. i am still getting the message on the dash that says service parksense and i cant turn the system on. i was wondering if anyone had a schematics of the parksense module so i can verify the harness is the right one. the one that goes with the vin for this truck comes up with just the rear fog lights. we crossed referenced the codes and found the harness that runs 4 sensors and thats it. but it didn't work. it still the same. i am wondering if it is the module or the harness is not right. on the 2 row of wires on the harness there is a wire coming off the main to the rear harness but no wire to meet it on the other end of the plug to the sensor harness. i don't know if it is supposed to be like that or not. i was looking under some jeeps in the lot and noticed there was some with 3 wires in the first row and others like mines. these 2 diffrent harnesses seam to be the only difference of the vehicles. there was nothing else hooked up to them but the park sensors. any advice or schematics