Some models have a problem were the transmission won't shift into fourth gear intermittently. This problem can commonly be repaired with a software update from Honda.
2009 Honda Ridgeline Problem Reports
Most Reported 2009 Honda Ridgeline Problem Reports
On some models a poor connection in the radio antenna harness and sub harness can cause static when going over bumps. Replacing the antenna harness and sub harness will commonly repair this problem.
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.
A chirp noise from the timing belt area can be caused by a tilted idler pulley. Installing a corrective shim from Honda will commonly correct this issue.
Noise and judder can develop from the rear axle due to differential fluid breakdown. Replacing the fluid will commonly correct this issue.