To Next PageTo Next PageWhy do Garmin GPS signal levels drop when avionics are turned on?
If the GPS signal levels drop when avionics are turned on, it's likely due to noise interference from other avionics. To resolve this, turn off all avionics, then turn them on one at a time to identify the source of the interference. Route the GPS cable and position the GPS antenna away from these interference sources.
How to improve low GPS signal levels on my Garmin?
Very low GPS signal levels can be caused by a few things. First, check the GPS antenna installation, connections, and cable routing, ensuring the antenna is mounted on top of the aircraft. Also, make sure the aircraft is clear of hangars, buildings, trees, etc., which could be shading the antenna from satellites. Finally, RF interference at 1575.42 MHz from VHF COM can be a factor; try moving the GPS antenna further from the COM antenna, adding a 1575.42 MHz notch filter in the COM coax, fixing or replacing the COM, or disconnecting the ELT antenna coax to check for possible re-radiation.
What to do if my Garmin 400W Series GPS unit does not transmit?
If the 400W Series unit doesn't transmit, it could be because the PTT input isn't being pulled low; check that the PTT (mic key) input is pulled low for transmit. Another reason could be no transmit power to the COM; ensure the power input is connected to the COM 25-pin connector P4002 11 and 12 and ground to P4002 21 and 22. The input voltage might also be too low; increase the input supply voltage to >12 VDC (>24VDC for 420 AW and 430AW models).
Why does my Garmin GNS 430W GPS keep 'searching the sky'?
The unit is actively searching for GPS satellites. Allow up to 20 minutes for the unit to complete its cycle or until your current position is located.
What to do if Garmin GNS 430W 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 from other avionics. To resolve this, turn off all avionics and then turn them on one at a time to identify the source of the interference. Also, try routing the GPS cable and positioning the GPS antenna away from potential interference sources.
What to do if Garmin GNS 430W GPS signal levels are very low?
Low GPS signal levels can stem from several factors: * Improper antenna installation or coax routing: Ensure the GPS antenna is correctly installed, with proper connections and cable routing. The antenna should be mounted on top of the aircraft. * Antenna shaded from satellites: Make sure the aircraft is in an open area, away from hangars, buildings, and trees. * RF interference: If there's RF interference at 1575.42 MHz from VHF COM, try moving the GPS antenna further from the COM antenna, adding a 1575.42 MHz notch filter in the COM coax, fixing or replacing the COM, or disconnecting the ELT antenna coax to check for possible re-radiation.
Why Garmin 400W Series GPS unit does not compute a position?
If your 400W Series unit isn't computing a position, there could be a few reasons: * Not receiving signals: Check the GPS antenna connections and ensure the aircraft is clear of obstructions like hangars, buildings, and trees. * Unit cycling: Wait 20 minutes for the unit to complete its cycle.
How to fix Garmin 400W Series GPS unit that does not power on?
If your 400W Series unit isn't powering on, the issue might be that the unit isn't getting power to the main connector P4001. Ensure power is connected to the main 78-pin connector P4001, pins 19 and 20, and ground to P4001, pins 77 and 78. Check the circuit breakers and main avionics switch as well.
How to resolve Garmin airport database integrity error?
If your 400W Series unit displays an “ database integrity error” message, it means the unit has detected a problem with a database on the NavData card, rendering the data unusable. Try reloading the information onto the card. If the problem persists, replace the card.
How to fix Garmin RS-232 device that is not communicating with the 400W Series unit?
If an RS-232 device isn't communicating with the 400W Series unit, there are several things to check: * 400W Series unit RS-232 port configuration: Check the RS-232 port setting for the port that the device is connected to. * Remote device setup: Verify the configuration of the other device. * Device compatibility and connection: Verify the 400W Series unit RX is connected to the remote device TX, and the 400W Series unit TX is connected to the remote device Rx. * Multiple TX lines: Verify that there is only one TX source per RX port. * Wiring: Check wiring.
General| WAAS | Yes |
|---|---|
| VHF Output Power | 10 Watts |
| COM Ports | 1 |
| GPS Channels | 12 |
| Database Update Interval | 28 days |
| Type | GPS/NAV/COM |
| Display | Color |
| Frequency Range | 118.00 MHz to 136.975 MHz (COM); 108.00 MHz to 117.95 MHz (NAV) |
| Voltage Range | 11 to 33 VDC |
| Channels | 200 (NAV) |
| GPS Receiver | WAAS |
| Approaches | ILS, VOR |
| Database | Jeppesen |
| Certification | TSO-C146a |
Describes the physical, mechanical, and electrical characteristics for installation and approval of 400W Series panel-mounted units.
Details FAA approval for installation within airplanes type-certificated under CAR 3 or 14 CFR Part 23.
Provides details on the 400W Series units, including their display and data card slots.
Covers the technical specifications of the 400W Series units, including physical and general characteristics.
Details physical specifications like bezel height, width, rack dimensions, and unit weights.
Lists TSO-C144 antennas meeting TSO-C146a requirements without operational limitations.
Details TSO approval conditions, tests, and references to Advisory Circulars.
Information on the aviation database, its generation, conversion, and update process.
Details on the terrain database, its update process, and download instructions.
General guidance on avionics installation practices and manual usage.
Details the required components for VFR and IFR GPS installations.
Guidance on selecting the most optimum location for GPS antenna installation.
Defines acceptable field-of-view for TSO C146a annunciations and GPS navigation data.
Details approval conditions for interfacing autopilots with the 400W Series unit.
Lists part numbers for 400W Series units and standard kit accessories.
Provides detailed parts information for Garmin GPS antennas.
Details dimensions and procedures for installing the mounting rack.
Provides information on GPS antenna cable installation and location considerations.
Lists pin functions for the P4001 main connector.
Details power input requirements and connections for the 400W Series unit.
Explains lighting bus input requirements for automatic brightness adjustment.
Lists antenna connector pin assignments.
Describes RS-232 and ARINC 429 data formats and their functions.
Explains COM/VOR/ILS audio activation, remote transfer, and transmit interlock functions.
Procedure to verify that all cables are secured and shields are connected correctly.
Steps to verify proper connector engagement before configuration and checkout.
Instructions for operating in Configuration Mode and selecting/changing configuration pages.
Configures GPS ARINC 429 output and input ports, including speed and function selection.
Allows changing selectable RS-232 inputs and outputs to match installed equipment.
Configures Fuel Type, Terrain Type, and Discretes options for the unit.
Monitors data on ARINC 429, RS-232, and other electrical inputs for verification.
Verifies communication with other instruments and displays status information.
Allows setting display backlight and key lighting brightness parameters.
Verifies operation of external switches and encoding altimeter input.
Verifies and calibrates MAIN CDI outputs and MAIN OBS input.
Verifies operation of external VLOC transfer switch.
Verifies and calibrates CDI outputs and OBS resolver input.
Configures VOR/ILS ARINC 429 output and input ports.
Function to enter the height above ground of the GPS antenna.
Shows WX-500 Stormscope configuration as reported via RS-232.
Displays L3 Communications SkyWatch or Ryan TCAD modes and traffic situation.
Shows TCAD's current shield settings and other configuration parameters.
Allows remote configuration of a GAD 42 Interface Adapter Unit.
Displays GDL 69 test word for various data link parameters.
Verifies lateral/vertical deviation, flags, and TO/FROM flag using selections.
Verifies that the lighting bus interface correctly varies display and key backlight levels.
Checks electrical outputs activated during the Instrument Panel Self-Test.
Verifies GPS position acquisition and reception during aircraft maneuvering.
Verifies the interface between the GNS 400W Series unit and a Honeywell EFS40/50.
Checkout procedure for two 400W Series units or one 400W and one 500W Series unit.
Verifies the interface between a 400W Series unit and a Sandel SN3500 EHSI.
Verifies traffic interface with SkyWatch or KTA 810 TAS/KMH 820 IHAS.
Verifies the correct interface of GDL 69/69A for XM Weather data.
Verifies GPS position during maneuvering and flight plan data consistency.
Ensures satisfactory performance of the communications transceiver during flight.
Provides a guide to troubleshoot problems occurring after installation.
Discusses operational limitations related to Part 23 aircraft, TSO qualifications, and AFMS.
States that no scheduled servicing tasks are required for the 400W Series unit.
References CFR 14 paragraph 91.171 for permissible indicated bearing error verification.
Provides instructions for cleaning the unit's bezel, keypad, and display.
Details the internal battery, its replacement, and warnings about lithium batteries.
Information on STC SA01933LA, Approved Model List, and Master Data List availability.
Lists approved aircraft models for installation based on AML STC SA01933LA.
Specifies RS-232 electrical interface compatibility and data generation parameters.
Describes the general format of the 400W Series RS-232 data output.
Details the general format for Type 1 output sentences.
Specifies RS-232C electrical interface and data input parameters.
Describes the 17-byte message format from Shadin Altitude Encoders.
Lists the mechanical drawings included in this appendix.
Lists approved audio panels and conditions for approval.
Lists approved Air Data Computers and conditions for approval.
Introduction to equipment interconnect diagrams approved per AML STC SA01933LA.
Lists the interconnect diagrams included in this appendix.
