TM 5-3805-291-23-1
THEORY OF OPERATION - CONTINUED
0003 00
POWERTRAIN - CONTINUED
5.
Transmission Neutralizer Function.
N OT E
When the transmission is neutralized, the readout on the Monitoring Messenger System continues to
show the selected speed but the direction will read Neutral.
When the transmission neutralizer is disabled, theneutralizer disable indicator on the dash is acti-
vated.
427-C1726
a.
Left pedal position sensor is located in the cab in the left brake pedal assembly. Left pedal position sensor is a pulse
width modulated (PWM) sensor which informs powertrain ECM of left brake pedal position. When left brake
pedal is depressed, left pedal position sensor sends a PWM signal to powertrain ECM, which uses PWM input to
neutralize transmission.
b.
Transmission neutralizer override soft-switch is an input of powertrain ECM used to decide if transmission neu-
tralizer should be disabled. Transmission neutralizer override switch is a momentary rocker switch.
c.
Left pedal position sensor signals powertrain ECM to neutralize transmission if transmission neutralizer is
enabled. When machine is started, transmission neutralizer is enabled. When transmission neutralizer override soft
switch is depressed and released, transmission neutralizer is alternately enabled or disabled.
d.
Transmission is neutralized by de-energizing selected direction clutch solenoid. Selected speed clutch solenoid is
still energized. Engine rpm will increase when transmission is neutralized to no-load condition from transmission.
This allows full hydraulic power for bucket operation.
0003 00-24
