TM-5-2350-378-24-P
HYDRAULIC DIAGNOSTIC CENTER (HDC) SUPPORTING ARMORED COMBAT EARTHMOVER (ACE), M9
TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST
TM-5-2350-378-24-P - Page 63 of 790
TM 5--2350--378--24&P
0005 00--4
USING THE HYDRAULIC DIAGNOSTIC CENTER (HDC) SYSTEM TO TROUBLESHOOT
THE M9 HYDRAULIC SYSTEM -- Continued
0005 00
d. Confirm that the ejector does not extend or retract. (This indicates that valve V23 is working properly.)
e. Stop engine and ensure that engine is off before connecting HDC control box.
3.
HDC Control Box power--up and operation.
WARNING
Do not activate the vehicle’s hydraulic control levers or depress any buttons on the
HDC control box unless directed by this procedure. Failure to comply could result in
serious injury or death to personnel.
a. Ensure vehicle power is off.
b. Remove HDC Control Box and umbilical cable W4 from stowage location behind driver’s seat.
c.
Place HDC Control Box in operating location.
d. Connect HDC Control Box and umbilical cable W4 to vehicle as per (WP 0004 00).
e. Place vehicle power on.
f.
Ensure parking brake is on and transmission is in neutral, then start vehicle engine. HDC System will not
receive operating power from vehicle unless parking brake is on and transmission is in neutral.
g. With the vehicle engine running and the transmission in neutral, turn the HDC Control Box on by
pressing the POWER button. (Depressing the POWER button again will turn the HDC Control Box off.)
Note that:
(1) Power to the HDC System is disconnected if the vehicle is taken out of neutral.
(2) The solenoid valves will return to their normal vehicle operating positions (de--energized/not powered)
when the HDC Control Box is turned off (or power is disconnected).
NOTE
The HDC System automatically initiates a start--up Built--In--Test (BIT) when power is
applied to the system.
h. After power is applied to the HDC System, and a start--up BIT is performed, if a BIT fault message is
displayed on the Liquid Crystal Display (LCD), do not use the HDC Control Box for testing.
i.
When system powers up, displays will be dark for 3 seconds. If significant sections of the displays are
missing, displays will be unreadable; do not use if displays are unreadable.
j.
If the temperature is below --4
_
F(-
-20
_
C), the displays will not come on until warmed up. The power
light will blink until the displays have warmed up.
k.
If the start--up BIT passed, and the HDC System is operating properly, the initial default display for the
status of the HDC System solenoid valves will appear as shown Table 1. This is the normal
de--energized (unpowered) state of the HDC System solenoid valves.
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