Ive been troubled by a TPMS error for about a year.  I have the 501 and have been able to conform activation and set the IDs to the TPMS controller.  Cleared the existing errors.  Light goes off after clearing of codes but then comes  comes on after a few miles, blinks 25 times and then stays on.  Controller diagnostics show transmit data error on all 4 tires.  Is it possible I have 4 bad sensors (they still show voltage good and correct pressure) or do you think I should take a chance and change the TPMS controller?