2011 ZX-10R. Black bikes matter!
Since it worked before the bike was serviced and not now, I'd inspect the harness and do a continuity check between the sensor plug and the ECU connector. It wouldn't be the first time that a harness got snagged and damaged during an engine removal.I did it, everything is perfectly like new...
This bike come from another shop, they removed the engine to change head gasket and after to build, blinking ktrc, code 16 and rev limit 6k...
Go to pages 667-670 in the service manual. It shows the corresponding pins on the ECU plug and how to test the system further.
Also, make sure that the connector plugged into the sensor has green, red/white, and blue wires. I know from previous experience that some of the harness plugs are identical and will plug just fine into the wrong components.