M2/M3 BFV: FIRE CONTROL SYSTEM - OD1608 - LESSON 2/TASK 3
c. Test Continuation - Isolating a Fault.
When the SETCOM
display shows a NO FAULT FOUND message, but a fault is present in the
system (i.e., the symptom which caused the test to be run in the
first place is still present), it will be necessary to perform more
tests to isolate the component that is causing the malfunction. When
the component causing the problem has been located and repaired or
replaced, test 2730 should be repeated to verify a NO FAULTS FOUND
(1) Testing Wiring Harness 2W203. This time the first suspect
component is wiring harness 2W203. To see if wiring harness 2W203 is
good, tests 2390 and 2391 are run:
(a) Perform test 2390 between plug 2W203P1 and jack 2W203J1.
If the test shows that wiring harness 2W203 is not good, replace the
wiring harness following the procedures in TM 9-2350-252-20-2-2, page
(b) If no problems are found in wiring harness 2W203 tests
during test 2390, perform test 2391 on jack 2W203J1.
If the test
shows that wiring harness 2W203 is not good, replace the wiring
harness following the procedures in TM 9-2350-252-20-2-2, page 5-301.
(c) If no faults are found in wiring harness 2W203 during
tests 2390 and 2391, the problem could be a loose connection.
Therefore, the next step is to check various connections for
(2) Testing Connections for Tightness. If the problem showing
up in the ISU controls and displays is not being caused by a faulty
wiring harness 2W203, move the MASTER POWER switch to OFF. Then turn
be checked to isolate the problem:
(a) Check the connection of cable 2W2P2 to 2AIJ12 and cable
2W5P5 to 2AlJ14 (refer to figure 58 on page 90) on the vehicle
distribution box. If either connection is not tight, tighten it.