I have a 2017 ZX14R that I bought used with 3500 miles on it. The bike runs perfectly but the neutral indicator will not come on and the gear indicator never shows the correct gear (sometimes in 6th it is right). The bike does have a Guhl flash and a PC5 (previous owner had done) and I was wondering if either of those may cause the issue I'm having.

I too have a '17 and sometimes it takes awhile to clear the code. So if the 6 hangs in the dash, it might be:
1. Connector not connected.
2. Wire out of connector.
3. Short or out of range is the gps.

Now you'll have to look down at the left [as you sit on the bike] down by the sprocket cover. Look for a green connector, light green wire of 4 at that connector. No wire out, right? Is connected, right? Then something is either short in the gps, or the flash is set for 6 and nothing is wrong with the gps.

So the question back is, was the 6 on when you bought it? Was N working when you bought it? If no, then sounds like a sensor or the N bulb is blown in the dash... just guessing here. If you lived close, we'd swap ECU's and find out if the flash is set to 6.

Thanks for the reply. It is not hanging on 6, it is more not showing the correct gear until I get to 6 and even then it is sporadic. 1st will be blank, 2nd may be blank or read 1st, and so on. Neutral light never comes on at all. It was this way when I bought the bike.

Sounds like a bad gps. It shows the sensor moving thru the gears, sorta. I'd remove the sensor off the engine. With it connected, key on, I then move the key slot or protruding tongue that moves it, or whatever slot design, all you are doing is moving the tongue/slot and watching if it does bring up N, and the other numbers. That or say the tongue is broken, the other side is damaged so the slot does not move with the shift.

Ah, so 1328 has the slot and is removable. So it's either broken off, or sensor 21176 is the problem. I'd start with the sensor removal and see if 1328 is broken.

https://www.cheapcycleparts.com/oemparts/a/kaw/5853074987a86609a0cd84b0/gear-change-drum-shift-fork-s

The PC5 would have no connection to the GPS. A pC5 must read gear position through the ECU if you want to tune/gear. At least that is the case for the Gen1 ZX-14 which has a different GPS than yours.

Check to see if the put the Tre module on it. If not Check the gear position sensor. Also try disconnection the PC5 as it could have gone bad or been programmed incorrectly..