I traded my 2007 RT for a 2013 Sport and I've run into a problem that the dealership can't seem to figure out. My new Ridgeline has the Optional Auto-Dim Rear View Mirror. The backup camera works flawlessly - but when not in reverse I have a blue letter C in the top left corner of the mirror. A search of the forums tells me the compass needs to be calibrated. I tried the calibration process outlined in the service manual - but I can't get the mirror into the calibration mode. I'd appreciate any help.