M2/M3 BFV: TROUBLESHOOTING - OD1610 - LESSON 2/TASK 1
e. Performing the STE Self-Test. The STE-M1/FVS has a built-in self-
testing capability that is used to determine that the test set is ready for
use. The self-test is also used to identify fault symptoms within the test
set, and to confirm that maintenance actions have corrected any previous
problem in the test set.
The self-test should always be performed before
using the test set on the vehicle.
The STE self-test consists of making various entries into the VTM or SETCOM
unit and receiving appropriate responses on the displays of those two units.
If, at any time during the self-test, the proper response is NOT displayed
by the test equipment, then the test set or component of the test set is
faulty.
(1) Powering Up the Test Set. Once the STE has been properly hooked
up to the vehicle, the power must be turned on. Set the power (PWR) switch
on the CIB to the ON position. Now push the circuit breaker on the VTM to
ON. The display on the VTM should show .8.8.8.8 for about two seconds and
then change to four dashes (- - - -). If this sequence is NOT displayed,
the STE test set is faulty, and the following actions should be taken.
If nothing appears on the display, check all cable connectors for tightness;
then, if nothing appears on the display, troubleshoot the STE test set for
the symptom NO VTM DISPLAY ON POWER UP, in accordance with TM 9-4910-751-14-
1, chapter 5.
If any one dot, number eight, or dash does not appear on the display,
replace the faulty display module, in accordance with TM 9-4910-751-14-1,
chapter 5.
If the VTM display shows blank, then shows .8.8.8.8, then is blank again,
troubleshoot the STE test set for the symptom VTM DISPLAY BLANK, THEN
.8.8.8.8, THEN BLANK, as outlined in TM 9-4910-751-14-1, chapter 5.
(2) VTM Confidence Tests. Two VTM confidence tests must be performed
as the first steps in the self-test.
(a) VTM Confidence Test 66.
To perform the first confidence test,
set the TEST SELECT switches
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