TM 5-3810-307-24-1-1
Table 2-3-5. Gear Selection Circuit Voltages
INPUT
OUTPUT
SOCKET
SOCKET
TRANS
TRANSMISSION SHIFT LEVER POSITION
SOCKET
CIRCUIT
ID (CAB
ID (ENGINE
ID
#
HARNESS)
HARNESS)
NAME
F1
F2
F3
F4
F5
F6
N
R3
R2
R1
L
789
K
1
Forward HI
24
24
24
C
788
B
2
Forward LO
24
24
24
24
24
24
J
598
H
3
2nd Range
24
24
24
24
24
24
G
597
F
4
1st Range
24
24
24
E
609
D
5
Reverse
24
24
24
b.
If voltage readings are not correct, gear
APC 100 CONTROL BOX DIAGNOSTICS
selector or cab harness is faulty.
Correct as necessary and check vehicle
1.
Remove blackout cover from APC 100 control
operation.
box to expose the three diagnostic LEDs.
9.
Ensure there is continuity in each output
2.
With transmission selector lever in N and
circuit, refer to Table 2-3-5. Ensure that there is no
ignition switch positioned to 1 (run), observe the
continuity between any two circuits and no continuity
three diagnostic LEDs and the TRANSmission RPM/
between any circuit and ground.
PRESSure indicator (LED) on dash panel. All four
should light for 2 seconds, then the TRANSmission
a.
If continuity is as stated, proceed to step
RPM/PRESSure indicator should begin to blink
10.
slowly and the red diagnostic LED should turn off.
The yellow and green LEDs should remain on.
b.
If continuity is not as stated, check the
harnesses and circuits in main junction
a.
If no LEDs light, check for 24 vDC power
box (exterior, back side of cab) for
and ground at the rectangular connector
cause. Correct any fault(s) and check
for the APC 100 control box harness.
vehicle operation.
(1)
If no power is indicated, check
NOTE
harness circuit #718.
Power
should be available at sockets
Since solenoids require less than 1 amp
17, 18, and 25 of APC relay box
of current to operate, even a small strand
harness. Correct any fault(s) and
of wire may cause undesirable continuity
recheck LEDs.
between circuits.
(2)
If no ground is indicated, check
10. Remove cover from fuse and relay box and
harness circuit #51.
Ground
check for loose connections, blown fuses, and bad
should be available at socket 11
relays. Correct any fault(s) and check vehicle
of APC 100 relay box harness.
operation.
Correct any fault(s) and recheck
LEDs.
NOTE
(3)
If power and ground are present,
The cab harness needs to be
check input fuse under top cover
reconnected
and
manual
mode
of APC 100 control box, refer to
reactivated for the relays to be in their
Figure 2-3-15. If blown, replace
manual mode position.
only with a 5 x 20 mm very fast
acting (FF) 315 mA fuse.
Recheck LEDs.
2-3-29
