Just found a dude on good ole ebay who rebuilds the c5 modules to your doors stock unit. Cost for a single rebuilt is a most reasonable $65 for the one troublesome relay. Promises a 24 hour turn around of the unit you send for repair. Shipping on your returned unit is paid by him and the final ,,,,,,repair is guaranteed for life.
My pass. door module is on it's way to him. I'll pass on info as I can.
Could be of some help, hope it is.