A sensor rod that is too long can cause the tailgate not to open in the swing mode. Replacing the sensor rod will commonly correct this issue.Google+
Car Problem Reports
Honda Ridgeline Tailgate Will Not Open Because Sensor Rod is Too Long
Honda Ridgeline Problem
Average Mileage: 62,220 mi (15,100 mi - 110,000 mi)
Visitor, 2007 Honda Ridgeline, 48,000 mi
Rear tailgate swing operation failed two weeks after I purchased it used from Family Ford in Enfield, CT. Dealership tried to fix it twice under their used car warranty until they found out how much it would cost to replace the sensor rod (over $1,000) -- after assuring me the repair was covered under warranty, they then informed me I was out of luck and that they had no interest in putting out the money for the repair.... Do NOT buy a car from these people....
Visitor, 2010 Honda Ridgeline, 15,100 mi
Tailgate latch for swing out operation of the tailgate has failed. Tailgate only operates in the up and down positions. Out of warranty due to 36 month threshold... Probably has not been opened 50 times over the past 3 years and, as a major selling point, should not have failed.
Visitor, 2008 Honda Ridgeline, 110,000 mi
Rear release to allow tailgate to open in swing mode is unresponsive
Visitor, 2009 Honda Ridgeline, 41,000 mi
Tailgate will not open. No solution at this time.