How to troubleshoot ARINC 429 device not receiving data from the Garmin GNS 480?
If an ARINC 429 device isn't receiving data from the GNS 480, check the ARINC 429 output port setting for the port that the device is connected to. Also, check the ARINC 429 output port speed setting for the port that the device is connected to and verify that the speed is correct for that device. Check wiring.
Why Garmin GNS 480 heading differs greatly from compass system (synchro hdg only)?
If the GNS 480 heading differs greatly from the compass system (synchro hdg only), check wiring, synchro X,Y,Z legs are crossed, 26VAC reference Hi and Lo are swapped. Verify that GNS 480 and compass system are using the same 26VAC reference.
What to do if my Garmin GNS 480 does not transmit?
If the GNS 480 is not transmitting, check that the PTT (mic key) input is pulled low for transmit. Also, make sure power input is connected to the COM 15-pin connector P4-1 and ground to P4-9. Increase input supply voltage to > 10 volts DC.
Why Garmin GNS 480 is not receiving heading from compass system (synchro heading input used)?
If the GNS 480 is not receiving heading from the compass system (synchro heading input used), check that the heading valid input (P5-57) is > 9 VDC. The state of this input can be checked in Ground Maintenance Mode. Also, check that 26VAC, 400Hz reference is supplied to P5-20,39. Check wiring.
How to fix Garmin GNS 480 not receiving baro correction data from MX20/GMX 200?
If the GNS 480 is not receiving baro correction data from the MX20/GMX 200, go to the serial port setup page and verify that RS-232 port 1 has MAPMX set for both CH 1 RX and CH 1 TX (only MX20 version 5.x or later supports the MAPMX protocol). Update MX20 software if the version is prior to v5.x. Check wiring.
What to do if autopilot is not getting GPSS/Roll Steering data from the Garmin GNS 480 (ARINC 429 Roll Steering used)?
If the autopilot isn't getting GPSS/Roll Steering data from the GNS 480 when using ARINC 429 Roll Steering, first ensure the GNS 480 has acquired a GPS position and a flight plan is entered. Then, check the ARINC 429 output port setting for the port that the autopilot is connected to. Also, check the ARINC 429 output port speed setting for the port that the autopilot is connected to and verify that the speed is correct for the autopilot. Check wiring.
How to troubleshoot Garmin GNS 480 not receiving heading from compass system (ARINC 429 heading input used)?
If your Garmin GNS 480 is not receiving heading from the compass system, and you're using ARINC 429 heading input, check the ARINC 429 input port setting for the port that the device is connected to. Also, check the ARINC 429 input port speed setting for the port that the device is connected to and verify that the speed is correct for that device. Check wiring.
Why are Garmin GPS signal levels very low?
If the GPS signal levels are very low on your Garmin GPS, check the GPS antenna installation, connections, and cable routing. The GPS antenna must be mounted on the top of the aircraft. Also, make sure the aircraft is clear of hangars, buildings, trees, etc. Another cause can be RF interference at 1575.42 MHz from VHF COM, in this case move GPS antenna further from the COM antenna, add a 1575.42 MHz notch filter in COM coax, fix or replace the COM, disconnect the ELT antenna coax to check for possible re-radiation.
What to do if my Garmin GPS GNS 480 does not compute a position?
If the GNS 480 isn't computing a position, ensure a correct position, time, and date have been entered. Check the GPS antenna connections and make sure the aircraft is clear of obstructions like hangars, buildings, and trees.
Why do Garmin GPS signal levels drop when avionics are turned on?
If the GPS signal levels drop when you turn on your avionics, it's likely due to noise interference. Try turning off all avionics and then turning them on one by one to find the source of the interference. Also, route the GPS cable and antenna away from potential interference sources.
General| Display Type | LCD |
|---|---|
| Interface | RS-232 |
| GPS Receiver | 12-channel |
| Database Storage | Jeppesen database |
| Navigation Capabilities | IFR/VFR, enroute, terminal, approach |
| Approach Types | ILS, VOR, LOC, GPS, WAAS |
| Compatibility | Compatible with most EFIS and autopilot systems |
| Operating Temperature | -20°C to +55°C |
Explains manual organization, scope, and purpose for installers.
Details GNS 480 features, system interfaces, and overall functionality.
Provides detailed electrical, physical, environmental, and performance specifications.
Lists TSO, ETSO, JTSO authorizations, FCC grant, and STC authorization.
Covers database updates, unpacking, and lists all items included in the GNS 480 package.
Lists optional accessories and related documentation for GNS 480 installation.
Specifies license requirements and provides definitions & acronyms.
Guidelines for installation practices, overview, materials, and special tools.
Discusses mounting, wiring, system configuration, environmental factors, and unit mounting.
Explains connectors, interfaces, and functional descriptions of GNS 480 systems.
Provides guidance for installing COM, GPS, and NAV antennas.
Covers weight/balance computation and electrical load analysis requirements.
Verifies mounting/wiring and guides GNS 480 setup and configuration.
Details checkout utilities: Test, Input Monitor, Ground, and Flight Checks.
Ensures database currency, card replacement, and AFMS update.
Provides a guide for diagnosing problems and contacting Garmin for support.
Describes operational limitations, recommendations for IFR use, and system safety.
Covers general installation responsibilities, antenna, equipment interfacing, and licenses.
No calibration needed; mandates periodic VOR accuracy checks and provides cleaning instructions.
Provides guidance on battery replacement and display backlight maintenance.
Lists environmental test categories and refers to STC authorization data.
Details RS-232 serial input and output specifications, including MapCom.
Lists compatible altitude sources and Fuel/Air Data Computers.
Lists compatible heading sources, altimeters, and autopilots.
Lists compatible Electronic HSIs, Traffic Systems, CO Detectors, and Displays.
Diagram showing power and antenna connections for GNS 480.
Diagrams illustrating connections to main and auxiliary CDIs.
Diagrams for baro, synchro heading, RMI, and RS-232 interface connections.
Diagrams for GNS 480 to audio panel and DME tuning connections.
Diagrams for connecting GNS 480 to S-TEC, Century, and Bendix/King autopilots.
Diagrams for single/dual GNS 480 stacks and NAV displays.
Lists suitable CDI/HSI source selection annunciators and vendor contact info.
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