TM-9-2540-207-14-P

HEATER, VEHICULAR COMPARTMENT, MODEL: A20

TECHNICAL MANUAL; OPERATOR, FIELD, AND SUSTAINMENT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST

JULY 2007

TM-9-2540-207-14-P - Page 182 of 288

TM 9-2540-207-14&P

6-18

6.5.24 E2 – LOW FUEL PRESSURE (Design Iteration 3 Only)

N

OTE

:T

HIS IS A WARNING ONLY

,

THE UNIT WILL NOT FAULT

.

T

O ELIMINATE THE WARNING

,

BOOST SUPPLY FUEL PRESSURE

.

FUEL SUPPLY PRESSURE TO THE HEATER IS BELOW 3.6 PSI

CHECK/POSSIBLE CAUSE

REF

.R

EPAIR

1

CHECK THAT VEHICLE OR SOURCE

FUEL PUMP IS OPERATING

2.6

RECONNECT SOURCE FUEL PUMP

RESTART HEATER

2

CHECK IF VEHICLE FUEL FILTER IS

PLUGGED

REPLACE FUEL FILTER

RESTART HEATER

3

CHECK FOR AIR BUBBLES IN THE

FUEL LINE.

BLEED AIR FROM FUEL LINES.

4

CHECK TO SEE IF FUEL LINE

LEADING TO HEATER IS PINCHED

OR OBSTRUCTED

STRAIGHTEN FUEL LINES AND REMOVE

OBSTRUCTIONS

RESTART HEATER

5

CHECK THAT THERE IS AMPLE FUEL

SUPPLY

TABLE 2-1

FILL FUEL TANK WITH FUEL

RESTART HEATER

6

ENSURE THAT FUEL PRESSURE

SENSOR IS CONNECTED TO WIRING

HARNESS

RECONNECT FUEL PRESSURE SENSOR TO

WIRING HARNESS PLUG P4 AND RECONNECT

WIRE HARNESS PLUG P1 INTO THE LOGIC

BOARD

RESTART HEATER

7

CHECK

WIRING HARNESS FOR

DAMAGE AND CONTINUITY

CHECK 3 WIRES FROM

PLUG P4 TO PLUG P1:

P4-PIN A TO P1-PIN17

P4-PIN B TO P1-PIN15

P4-PIN C TO P1-PIN16

CHECK FOR SHORT :

P4-PIN A TO CHASSIS SHOULD BE OPEN LINE

P4-PIN B TO CHASSIS SHOULD BE OPEN LINE

P4-PIN C IS THE GROUND

IF ANY CHECK FAILS

REPLACE WIRING HARNESS

RESTART HEATER

8

DEFECTIVE FUEL PRESSURE

SENSOR

5.5.1

REPLACE FUEL PRESSURE SENSOR

RESTART HEATER