Is the switch working for reverse light? As I wrote above, I don't recall gears being shown on the digital display, like you get on other digital dash Hondas, but that switch can be put 180 degrees out. Had a 420 auto in a few weeks back, a mower repair shop had fitted a new pulse coil and found the gears wouldn't work afterwards, they sent it to me, and I got neutral light on with grounding the pale green, twigged straight away that they had fitted the switch 180 degrees out, (did it myself years ago). That really did confuse the auto gearbox computer.

 

This machine was all original. It was the neutral switch. After I was able to find the harness for the switch and figure out it was behind the stator cover I was able to ground the light green and got neutral light and it started right up. It would only shift into first and then the light would blink because it needed the neutral light to go out when in gear.