Disklavier IV is most confusing adjustment in Disklavier series.
Please call a hybrid piano professional tuner from YAMAHA.
He should have maintenance manual .
1:acoustic damper and shift pedal adjustment.
Check X , Y line and each sensor LED loght in range.
2:Pedal rod clearance adjustment.
3:Enter Service center mode
4:Enter maintenance mode(push D M P within 0.5sec)
5:Enter Data base mode
6:Enter Log View mode
analyze error log and find the bad part.(pedal/key/motor/sensor/power unit)
7:Enter search point mode
8:Enter right pedal or Left pedal or other mode
9:check error log , warning log stroke and temp history.
10:Find the bad point and fix it.
11::Acoustic regulation piano action and keyboard.
12:All Keyboard and pedal measurement.
13:Do the test playing.
Good luck..
(・ω<)