
EGPWS LINE MAINTENANCE MANUAL
CAGE CODE: 97896
SCALE: NONE SIZE: A
DWG NO.: 060-4199-180
REV: G
SHEET 29 of 68
TABLE 3-4: LEVEL 2 SELF-TEST - EXTERNAL FAULTS
THE FOLLOWING EXTERNAL FAULTS ARE AVAILABLE IN LEVEL 2 SELF-TEST:
Enunciation:
“<BUS> Inactive”
Example:
GPS BUS 1 Inactive
Probable Cause:
Input source not powered or a wiring problem exists between source LRU and the
EGPWC.
Action:
Verify input source LRU is powered. Verify wiring from the source LRU. Verify program pin
configuration.
Enunciation:
“<BUS><SIGNAL> FAULT”
Example:
ILS BUS 1 GLIDESLOPE FAULT
Probable Cause:
Input signal SSM = Fail Warning, or Input signal is not being transmitted (incorrect update
rate).
Action:
Repair input signal.
Enunciation:
“<SIGNAL> FAULT ESE” (See Table 3-5 for other failure codes)
Probable Cause:
External signal is outside reasonable limits
Action:
Verify signal scaling
Enunciation:
“<BUS> WIRING FAULT”
Example: RADIO
ALTIMETER 1 WIRING FAULT
Probable Cause:
Open wire monitor has detected no connection from the source LRU.
Action:
Verify wiring from the source LRU.
Enunciation:
“FLAP SWITCH FAULT”
Probable Cause:
Electrical short at the flap discrete input.
Action:
Verify wiring from the flap override switch and/or flap input discretes.
Enunciation:
“GEAR SWITCH FAULT”
Probable Cause:
Electrical short at the gear discrete input.
Action:
Verify wiring from the gear override switch and/or gear input discrete.
Enunciation:
“AUDIO CANCEL INVALID”
Probable Cause:
Electrical short at the audio cancel input.
Action:
Verify wiring from the audio cancel switch.
Enunciation:
“ALL MODES INHIBIT INVALID”
Probable Cause:
Electrical short at the audio cancel input.
Action:
Verify wiring from the audio cancel input.
Enunciation:
“GLIDESLOPE CANCEL INVALID”
Probable Cause:
Electrical short at the glideslope cancel input.
Action:
Verify wiring from the glideslope cancel input.
Enunciation:
“ILS SELECT INVALID”
Probable Cause:
Electrical short at the ILS Select inputs.
Action:
Verify wiring from the ILS Select switches.
Enunciation:
“FLAP ANGLE UNREASONABLE”
Probable Cause:
Electrical short at the flap discrete input(s).
Action:
Verify wiring from the flap-input discrete(s).