New Holland T8010 Manual page 1536

Section 55 - Electrical System, Controller - Chapter 4
FAULT CODE TRANS
38 Shuttled to reverse when no wheel speed signal
Cause:
This fault code will be recorded when the operator attempts to shuttle to reverse from 13 gear forward or higher and
there is Fault code 77 (no transmission output RPM signal).
Solution:
Correct the no transmission output RPM signal fault following the trouble-shooting procedures for fault code 77.
Otherwise, shift to forward or cycle the shuttle lever. Reverse will be available 10 seconds after the last time that the
shuttle lever was in forward without the clutch pedal down.
55-4-9