Garmin MX20 Installation Manual - page 65
Troubleshooting
58
MX20 Installation Manual
Table 5-1. Troubleshooting Guide Cont’d
Problem Cause
Solution
4. Waypoint not selected as the
current destination.
4. If a GX/SL series is used as the position
source, ensure that a waypoint is selected as the
current destination (Nav Flagged is not shown
on primary Nav page).
5. Position source not configured on
appropriate port.
5. If a GX/SL series is used as the position
source, ensure that it is configured to
output serial data (MOV MAP) on the
appropriate port.
6. External GPS not properly
configured.
6. If other compatible external GPS is used,
ensure it is configured to output serial
position data on the appropriate lines.
Unit shows POS data flag
(cont’d).
7. RF interference.
7. Ensure no RF interference at 1575 MHz
from VHF Comm antenna – add 1575
MHz notch filter in Comm coax; Fix or
replace Comm; Disconnect the ELT
antenna coax to check.
Unit shows RTE data flag.
1. External position source does not
have active route engaged.
1. Ensure that the external position source
has an active route engaged.
1. Data port configuration incorrect. 1. Ensure that the data port configuration is
correct and matches how the unit is wired
for the serial altitude source.
2. Serial altitude encoder not
powered up; not functioning
properly.
2.
Ensure that serial altitude encoder is
powered up and functioning properly.
3. System is configured to use GX
unit as source for altitude data
and GX is not turned on.
3. Ensure GX is turned on, shows a valid
altitude, and has acquired position and
valid waypoint.
Unit shows ALT data flag.
4. System is configured to use GX
unit as source for altitude data
and GX not configured properly.
4.
Verify that GX has extended data output
enabled.
1. Terrain database incorrect.
1. Ensure the unit has the appropriate
terrain database loaded for the area of
operation. The terrain database is
indicated on the power-up and system
status pages of the MX20.
Unit shows TER data flag.
2. Invalid altitude supplied to unit.
2. Ensure that valid altitude is being supplied to
the unit (an ALT data flag should not be
present).