Honeywell MK V Line Maintenance Manual page 29

THE FOLLOWING EXTERNAL FAULTS ARE AVAILABLE IN LEVEL 2 SELF-TEST:
Enunciation: "<BUS> Inactive"
Example: GPS BUS 1 Inactive
Input source not powered or a wiring problem exists between source LRU and the
Probable Cause:
EGPWC.
Verify input source LRU is powered. Verify wiring from the source LRU. Verify program pin
Action:
configuration.
Enunciation: "<BUS><SIGNAL> FAULT"
Example: ILS BUS 1 GLIDESLOPE FAULT
Input signal SSM = Fail Warning, or Input signal is not being transmitted (incorrect update
Probable Cause:
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).
CAGE CODE: 97896 SCALE: NONE
EGPWS LINE MAINTENANCE MANUAL
TABLE 3-4: LEVEL 2 SELF-TEST - EXTERNAL FAULTS
SIZE: A DWG NO.: 060-4199-180 REV: G SHEET 29 of 68