TM 5-3810-307-24-1-1
TEST PROCEDURES WITHOUT CHECKOUT KIT
TRANSMISSION
RPM/PRESSURE
INDICATOR
(1)
Check transmission system for
DIAGNOSIS
adequate
clutch
(regulated
system) pressure (240-280 psi
with oil at 180-2500F, engine at
This indicator, located on the carrier cab dash panel,
is used to convey warning signals when in
idle, and transmission in N.
AUTOMATIC shift mode.
The signals and
Remove pressure switch (at 4WD
associated errors are:
solenoid) and replace with
pressure gauge to measure
1.
On - Transmission Overspeed:
pressure.
a.
Vehicle must slow down to extinguish.
(2)
If pressure is low, check for
improperly routed transmission
b.
If slowing vehicle does not extinguish
hoses to 4WD solenoid valve and
indicator, proceed to Speed Sensor
lockup modulator valve (located
Inputs.
on right wall of transmission well),
refer
to
FO-2,
Hydraulic
2.
Fast Blink - Turbine failure: The computer has
Schematic for proper routing.
lost turbine speed input signal, refer to Speed
Reroute hoses as necessary.
Sensor Inputs.
(3)
If pressure is correct, check
3.
Slow Blink - Low clutch pressure for more than
pressure switch for proper
5 seconds. This condition will exist with ignition
operation.
Switch should be
switch on until adequate pressure is developed
open with system pressure.
within transmission circuits.
Replace as necessary.
a.
If indicator does not blink with ignition
SHIFTING PROBLEM DIAGNOSIS
switch on and engine stopped:
1.
Operate vehicle in both AUTOMATIC and
(1)
Check that clutch pressure switch
MANUAL shift modes.
is closed with no pressure.
Replace as necessary.
a.
If symptom only occurs in AUTOMATIC
mode, proceed to APC 100 CONTROL
(2)
Check for 24 vDC power at
BOX DIAGNOSTICS.
pressure switch wire 44 (at 4WD
solenoid) and continuity from wire
b.
If symptom occurs in both modes,
920 to socket #7 of relay box
proceed to step 2.
harness connector (rectangular
connector. Correct as necessary.
2.
Check if rear steering is unlocked. The
electrical system limits the transmission to F1, F2,
(3)
Check indicator for proper
and R1 when rear steering is unlocked.
operation. Correct or replace as
necessary.
a.
If rear steering is unlocked, lock it and
recheck operation.
(4)
Proceed to APC 100 CONTROL
BOX DIAGNOSTICS.
b.
If rear steering is locked and symptom
persists,
proceed
to
MANUAL/
b.
If indicator stays lit with engine running:
AUTOMATIC
SHARED
SYSTEM
DIAGNOSTICS.
2-3-27
