Problamatic rear parking sensor

[racerock3]

Hi,currently sorting out a few problems on my friends ZT-T,bonnet light sorted , DD steering wheel audio controls sorted,next the parking sensor when reverse is selected a tone is heard for about 15 seconds,then nothing,even right against a wall.I know most of the checks (cable prob's and sensors)but dont know if the unit is actually working.are there any checks I can do?or is it the dreaded T4?
Any help would be appreciated
regards:bowdown::bowdown::bowdown:

[1gp]

Put it in reverse , and see if you can hear the sensors clicking . if you have one not working, it stops the lot from working.. it will be a wire that has broke they cable tie them to the bumper, and it brakes the wire. bumper off and check all wires...:}

[Thomas]

Moved to technical help forum