EFD1000 E5 Dual Electronic Flight Instrument (EFI) Install Manual
DOCUMENT # 900-00041-001
PAGE 182-226
REVISION D
© Copyright 2019 Aspen Avionics Inc.
Fault
Cause
Corrective Action
ATTITUDE DEGRADED
message
a) In Flight, Normal if pitot
blockage due to ice or
other.
a) Use pitot heat or check pitot system for
blockage.
b) On Ground, Normal if
GPS reception is
marginal and GPS GS
ramps above 50Kts
intermittently.
b) No further action required unless
message is due to faulty GPS system, then
repair GPS system.
CROSS CHECK ATTITUDE
message (yellow)
(also see sluggish AHRS
performance
troubleshooting)
a) If it occurred on system
start.
a) RESET AHRS
b) Normal after abrupt
maneuvers on ground or
in air
b) RESET AHRS
Red Slash through
Navigation Sensor
(i.e., GPS1, NAV2)
a) GPS or VLOC receiver
turned off.
a) Turn on GPS or VLOC receiver
b) GPS does not have a valid
“TO” waypoint and
position
b) Allow GPS to acquire a position and enter
a flight plan or Direct To
c) GPS or VLOC receiver
failed
c) See GPS/VLOC manufacturer’s instructions
for troubleshooting
d) ACU not powered
d) Check ACU circuit breaker
e) Wiring fault between
sensor and ACU or EFD
e) Check wiring between GPS/VLOC and ACU
or EFD
f) ACU to EFD wiring fault.
f) Check ACU circuit breaker, check ACU to
EFD A429 wiring and ACU to sensor
wiring
g) ACU is defective.
g) Repair or replace ACU
h) EFD is defective.
h) Repair or replace EFD
GPS1 selection not
available on Display
(GNS430/GNS530/GNS480
only)
a) GPS receiver turned off
a) Turn on GPS and initialize
b) GPS does not have a valid
“TO” waypoint and
position
b) Allow GPS to acquire a position and enter
a flight plan or Direct To
c) GNS CDI is selected to
VLOC.
c) Verify the GNS CDI is selected to GPS.
d) GPS to EFD A429 wiring
issue.
d) Check A429 wiring for shorts, opens or
crossed A and B lines.
e) GPS defective.
e) Repair or replace GPS
f) EFD defective.
f) Repair or replace EFD