TM 9-6115-730-24
0013
ELECTRONIC TECHNICIAN (ET) TROUBLESHOOTING - Continued
CORRECTIVE ACTION - Continued
STEP 7.
Check the throttle position using the Cat ET.
a. Observe the position of the throttle on the Cat ET.
b. Set Battery Disconnect Switch to ON. Set DEAD CRANK SWITCH to
NORMAL. On EMCP set ENGINE CONTROL switch to COOL
DOWN/STOP.
c.
Turn the FREQUENCY adjust knob to register the following:
60 Hz between 1700 and 1900 rpm
50 Hz between 1400 and 1600 rpm
d. Start at the low position. Slowly turn the FREQUENCY adjust knob in the
other direction. Monitor the position of the Throttle and the RPM on the Cat
ET.
e. If the throttle position shown on the Cat ET changes as the FREQUENCY
adjust knob is adjusted, LSM A4 is operating correctly.
f.
If the throttle position and RPM reading shown on the Cat ET does not vary
as the FREQUENCY adjust knob is adjusted. Proceed to STEP 8.
STEP 8.
Check LSM A4.
a. On EMCP set ENGINE CONTROL switch to OFF/RESET. Set Battery
Disconnect Switch to OFF. Set DEAD CRANK SWITCH to OFF.
b. Remove wires from terminals 19 and 20 of LSM A4.
c.
Connect DC voltmeter to terminals 19 and 20 on LSM A4.
d. Set Battery Disconnect Switch to ON. Set DEAD CRANK SWITCH to
NORMAL. On EMCP set ENGINE CONTROL switch to COOL
DOWN/STOP.
e. Turn FREQUENCY adjust potentiometer up and down. Voltage will vary
from approximately 4.5 to 9.5 Vdc.
f.
On EMCP set ENGINE CONTROL switch to OFF/RESET. Set Battery
Disconnect Switch to OFF. Set DEAD CRANK SWITCH to OFF.
g. If voltage is incorrect, or erratic, repair wiring as necessary (WP 0088).
Verify the problem is resolved. If wiring is good, perform potentiometer test
on FREQUENCY adjust potentiometer (WP 0041). Replace potentiometer,
as required (WP 0041). Verify the problem is resolved.
h. If FREQUENCY adjust potentiometer is not defective, replace LSM A4
i.
If voltage is correct, remove ENG-P1 connector from the ECM. Measure
continuity from the wire on terminals 19 to ENG-P1-66 and the wire on
terminal 20 to ENG-P1-5. If continuity is good, replace ECM (WP 0082).
Verify the problem is resolved.
0013-25
