The accelerator pedal position sensor assembly (mounted in the upper, rear of the engine compartment on the passenger's side) contains two, redundant potentiometers. Both must agree within a specific tolerance or the throttle blade won't be allowed to open normally. A discrepancy in either of these sensors will result in a DTC.
As a side note, I was surprised by Honda's implementation of BTI (Brake Throttle Interlock) on my '14 Ridgeline. The engine will still rev to the stall speed of the torque converter at a stop with the brake and accelerator applied simultaneously. Even when the vehicle is in motion, I can still accelerate while the brake pedal is depressed, although I can tell the throttle opening is limited. In some other vehicles I've driven with BTIs (a rental Nissan Versa and Toyota Sienna come to mind), the throttle won't respond at all if your foot is on the brake.