LIMP HOME/TRANSMISSION FAULT
ALLISON 4500SP TRANSMISSION WILL NOT SHIFT INTO OR OUT OF GEAR (CHECK TRANSMISSION
If transmission range selector flashes current range selection while operating vehicle (shift
selection is inhibited), DO NOT SHUT OFF ENGINE or attempt to change range selection.
Shutting off engine may result in the inability to select a drive range at startup, and diagnostic
data may be lost. Move vehicle to safe place and notify field level maintenance as soon as
When transmission oil is below 19°F (-7 C), the only gears available are R (reverse), N
(Neutral), and 3 (third gear range) when D (drive) is selected. The remaining gears in D
(drive) will not be available until transmission oil in sump warms above 19°F (-7 C).
1. If check transmission indicator (1) illuminates when operating vehicle, apply service brake pedal (2) and stop