Hi, on dash video screen is red line all around the 360 veiw, indicating a fault , no sensors working . But theres no error code showing.  Is there a route to method to reach tests for 6 front, 6 rear 2 puddle sensors(wade)  or do i have to try and "feel for a pulse" and hope that its correct one to replace.  Had scanner seems a while 4 years or more, pay for updates annually.