TM 5-3810-307-24-1-1
Speed Sender Input Diagnostics
2.
The TORQUE CONVERter UNLOCKED
indicator should illuminate when ignition switch is
1.
Disconnect relay box harness (rectangular
turned on. If it does not light, check electrical circuit
connector) from APC 100 control box.
and indicator. Correct any fault(s) and proceed to
step 3.
2.
Position ignition switch to 1 (run).
3.
Disconnect relay box harness (rectangular
3.
Check resistance between sockets 28 and 29,
connector from APC 100 control box and place
and sockets 30 and 31 of relay box harness
ignition switch to 1 (run).
connector. Resistance should be 1000-1200 ohms.
4.
Check socket 25 (lockup request input) of
a.
If resistance readings are as stated,
harness connector for 24 vDC.
proceed to step 4.
a.
If voltage is absent, check fuse and relay
b.
If
resistance
readings
are
not
box for faulty wiring or loose connection.
acceptable, check appropriate circuit.
Correct any fault(s) and recheck
Correct any fault(s) and recheck
voltage.
resistance.
b.
If voltage is present, proceed to step 5.
4.
Place crane on outriggers, start engine from
carrier cab, place transmission shift lever in F1, and
5.
Measure resistance between socket 37
run at idle.
(lockup output) and socket 11 (ground). Resistance
should be 30-60 ohms.
5.
Measure AC voltage between sockets 28 and
29, and sockets 30 and 31 (turbine speed). Voltage
a.
If reading is not as stated, check
should be 5-10 vAC. If voltage reading is less than 3
harness, fuse and relay box fuse FU8
vAC, check speed sender for damage. Replace
and connections, and solenoid for faults.
sender if damaged and recheck voltage.
Correct any fault(s) and recheck
resistance.
NOTE
b.
If reading is acceptable, reconnect APC
Clearance is preset by bushings installed
100 relay box harness and proceed to
in transmission and should not be a
step 6.
problem.
6.
Attach a voltmeter to wire 448 at lockup
Torque Converter Lockup Diagnosis
solenoid modulator valve. Use a jumper wire if
necessary and secure wires away from driveshaft to
NOTE
allow taking reading safely with driveshaft rotating.
For proper lockup operation, APC 100,
7.
Place crane on outriggers, with tires off the
throttle switch inputs, gear selector
ground, and start engine from carrier cab.
inputs, and speed sender inputs must be
functioning properly, refer to appropriate
8.
Position transmission shift lever to F4, release
procedures and check functions prior to
brakes, run engine at 2200 rpm, and allow
diagnosing lockup problems.
transmission to enter F4 gear. Lockup may occur in
F3 since engine speed is below full throttle switch
1.
Lockup is allowed in gears F4 thru F6 and also
setting.
in F3 when the throttle is less than mid-throttle. The
crane will feel sluggish, fuel economy will suffer, and
9.
As turbine speed (torque converter output)
top speed will be difficult to achieve if lockup is not
surpasses minimum speed (refer to Table 2-3-7) and
functioning. The operator can usually feel lockup
approaches engine speed, TORQUE CONVERter
engaging (feels like a smooth prolonged shift to a
UNLOCKED indicator should turn off, the voltage
higher gear) about 3 seconds after TORQUE
reading at lockup solenoid should change from 0 to
CONVERter UNLOCKED indicator turns off.
24 vDC, and lockup should occur.
2-3-33
