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

Check 3-6: Neutral Indicator Light (LED) Inspection
Meter Unit Circuit (ZX1000J Model)Break-in
The first 1 600 km (1 000 mi) that the motorcycle is ridden is designated
as the
break-in period. If the motorcycle is not used carefully during this period, you
may
very well end up with a “broken down” instead of a “broken in” motorcycle after
a
few thousand kilometers.
The fol ...
Check 2-3: Intake Air Temperature Inspection
Disconnect the intake air temperature sensor connector
[A] (see Intake Air Temperature Sensor Removal in the
Self-Diagnosis System chapter).
Connect the variable rheostat [B] to the R/BK lead [C] and
BR/BK lead [D] terminals.
Turn the ignition switch to ON.
Read the temperatur ...
Meter Unit Removal/Installation
Remove the upper fairing assembly (see Upper Fairing
Assembly Removal in the Frame chapter)
Remove the bolt [A] (other than US, CA and CALmodels).
Slide back the dust cover and disconnect the meter unit
connector [B].
Remove:
Bolts [A]
Nut [B] (other than US, CA and CAL mode ...