MAINTENANCE OF M939 SERIES VEHICLES - OD1661 - LESSON 1/TASK 2
GENERAL TROUBLESHOOTING RULES
(1) Question the vehicle operator to obtain any information that
might help determine the cause of the maintenance problem.
(2) Never overlook the chance that the maintenance problem could
be of simple origin. The problem could possibly be corrected with a
Use all senses to observe and locate troubles.
(4) Use test instruments or gages to help determine and isolate
(5) Always isolate the system where the malfunction occurs and
then locate the defective component.
In the following paragraphs, the troubleshooting procedures for six
malfunctions from six of the 21 mechanical subsystems of the M939 FOV
will be discussed.
For the purposes of these paragraphs, we will
The troubleshooting test results
described here are not the only possibilities.
M939, consult TM 9-2320-272-20-1.
In the following paragraphs we
will follow SGT Elliott as she troubleshoots the malfunction: ENGINE
FAILS TO CRANK and reaches the conclusion that the starter is
One of the first things that SGT Elliott does is read DA Form 2404
and talk to the operator.
This is done so that she will have a
better understanding of the malfunction and to possibly gain any
additional information that may be helpful in troubleshooting.
operator, SGT Elliott then reads through the troubleshooting
necessary tools, special tools, and test equipment necessary to