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

Check 3-6: Neutral Indicator Light (LED) Inspection
Meter Unit Circuit (ZX1000J Model)Exhaust Butterfly Valve Actuator Inspection
NOTE
Be sure the battery is fully charged
Remove the front seat (see Front Seat Removal in the
Frame chapter).
Turn the ignition switch to ON.
In the left side view of the motorcycle, check to see
the pulley [A] clockwise [B] and counterclockwise [C]
smoothly.
The pulley turns ...
Crankshaft Sensor Peak Voltage Inspection
Refer to the Crankshaft Sensor Peak Voltage Inspection
in the Electrical System chapter.
If the reading is within the standard, remove the ECU and
check the wiring for continuity between harness connectors.
Special Tool - Hand Tester: 57001-1394
Disconnect the ECU and sensor connector ...
Mud Guard Installation
Installation is the reverse of removal. Note the following.
Run the hose and lead correctly (see Cable, Wire, and
Hose Routing section in the Appendix chapter).
Check the brake line.
Apply a non-permanent locking agent to the threads of
the mud guard mounting bolts [A, B], and tighten them ...