If the display function does not work, replace the meter unit.

Check 3-6: Neutral Indicator Light (LED) Inspection
Meter Unit Circuit (ZX1000J Model)Outline
When a problem occurs with DFI system, the warning indicator
light (LED) [A] and FI warning symbol [B] goes on
to alert the rider. In addition, the condition of the problem is
stored in the memory of the ECU. For models equipped with
an immobilizer system, the warning indicator light (LED)
and ...
Transmission Assy Removal
Remove:
Engine Sprocket (see Engine Sprocket Removal in the
Final Drive chapter)
Gear Position Switch (see Gear Position Switch Removal
in the Electrical System chapter)
Collar [A]
O-ring [B]
Remove:
Clutch (see Clutch Removal in the Clutch chapter)
Shift Shaft Assembly ...
Clutch Installation
Apply engine oil to the needle bearing [A] and the sleeve
[B].
Install:
Needle Bearing
Sleeve
Install the clutch housing [A].
Fit the holes [B] and projections [C].
Engage the clutch housing gear and the crankshaft primary
gear.
Install the spacer [A] and the clutch ...