Table A-3 Gra 5500 Fault Descriptions - Garmin GRA 5500 Installation Manual

Table A-3 identifies the various unit faults that can be encountered during normal operation of the GRA 5500. Use Table A-3 as a reference to
determine the proper actions to take after a fault has been identified.
Fault Type Fault Name
Configuration N/A
Zero-Foot Lock
Calibration
Zero-Foot Cal
PLL Register
RF Self-Test
POST (Power On
Self-Test)
Sensor Boot
Various
(see Table
190-01277-00
Revision A

Table A-3 GRA 5500 Fault Descriptions

Description
Unit does not boot
Average frequency of
zero-foot signal is
larger/smaller than
allowable
frequencies
Zero-foot point not
set
After programming,
read-back of the PLL
register values does
not match what was
sent from the CPU
The self-test signal is
not within the
acceptable frequency
range
Sensor processor
software not
successfully loaded
Numerous tests
identified in this table
are run during Power
On Self-Test (POST).
Failure of these tests
A-4) is identified as a
POST fault during
power up and also
identified by the fault
name in the fault log.
(continued on next page)
Cause
GRA HW Revision ID
Update software to correct version for hardware
invalid for SW version
GRA Unit ID invalid
(Both discrete inputs Check Unit ID strapping and set to a valid ID
grounded)
Hardware failure Return unit to Garmin for service
Check antenna installation and all cable
Improper antenna
connections and retry calibration. Note there are no
connections
assert log entries for this fault.
Antenna cables are
too long or calibration Calibrate unit while on ground. Note there are no
completed while assert log entries for this fault.
aircraft is in air
Calibration not Calibrate the unit. Note there are no assert log
complete entries for this fault.
Internal Cycle power to unit. If fault persists, return unit to
communication error Garmin for service.
Improper antenna Check antenna installation and all cable
connections connections
Download the assert log and send to Garmin for
Internal failure diagnosis. If fault persists, return unit to Garmin for
service.
Internal Cycle power to unit. If fault persists, return unit to
communication error Garmin for service.
Various Cycle power to unit. If fault persists, return unit to
(see Table A-4) Garmin for service.
Resolution
GRA 5500 Installation Manual
Page A-3