Select your product to confirm this information applies to you

Garmin® Marine Device Shows No Sonar Option or Depth Reading

If a Garmin® marine device with an attached sonar transducer shows no sonar option or depth readings, it could be impacted by one or more of the the following factors:

  • Cavitation, or air bubbles going across the transducer that interfere with sonar readings

    • This may be caused by boat speed, transducer placement, or water turbulence

  • Sonar transmission

    • If the sonar transmission is disabled, then the sonar transducer won't function or return depth (Enable 'Transmit' setting in the sonar menu  to continue with operation of sonar)

  • Transducer condition

  • Transducer connection

    • Corrosion to the connection at the sonar port of a chartplotter, sonar module, or sonar transducer cable will cause sonar malfunction and connection loss (Remove and check any sonar connections, including extension cables, for discoloration or resistance)


NOTE: Transducers connected to the marine device using the NMEA 0183 or NMEA 2000 networks will not show sonar images, but depending on the transducer features, they will display depth, speed, and/or temperature readings.


Before troubleshooting the device, restore sonar defaults:

  • Current chartplotters from the sonar screen select ... / Options > Sonar Setup > Installation > Restore Sonar Defaults

  • Striker series from the sonar screen select the Menu Menu Button Striker Series > Sonar Setup > Installation > Restore Sonar Defaults

  • Previous chartplotter models see the Owner's Manual for accessing the sonar reset option


Select the scenario below for troubleshooting steps:

Device's home screen does not display sonar options

Garmin marine devices will not display a sonar option on the home screen if it does not detect a connected transducer or sonar module.

Check that the chartplotter and transducer models support the type of sonar view missing, such as ClearVu™, SideVu™, or Panoptix™. Go to garmin.com to search for specifications.

Error messages

    • If the device displays the message Transmission disabled, see the owner's manual for steps to re-enable transmission

    • If the device displays the message Sonar Transducer Disconnected, there may be a connection problem between the transducer and marine device, powered mount, or sonar module

Troubleshooting transducer connection issues

      • Check that the transducer is securely connected. Use a locking collar (also known as a split connector) if present

        • Make sure the notch on the transducer cable and the transducer port is aligned when re-connecting

        • If there is no locking collar on the transducer cable, a split connector can be purchased from the device's accessories page on garmin.com

        • See Marine Cable Collar Installation for instructions to install the locking collar

        • If using a wire block adapter, check that the bare wire connections to the block are securely connected to the correct ports

      • Check for corrosion at all connection points:

          • The transducer cable connector head

          • The transducer port on the device or powered mount

          • The wire ends and wire block adapter if one is in use

        • Light corrosion can be cleaned using a brush and dielectric grease

        • Heavy corrosion may have extended into the cable, the device, or the powered mount itself, which will need to be replaced

        • It is recommended to use a weather cap to protect the transducer port when the transducer is disconnected

          • Replacement weather caps can be purchased from the device's accessories page on garmin.com

      • If using a transducer extension cable, use as few as possible to connect the transducer to the marine device


Other troubleshooting steps

    • If there are crimps or cuts in the transducer cable, the transducer may not be able to transmit information and will need to be replaced

    • If the transducer is connected to an external sonar module, see Troubleshooting Marine Sonar Modules for further steps

    • The transducer must be clear of any fouling or scratches to get a depth reading

    • If using a transom-mounted or trolling motor-mounted transducer, power on the chartplotter, take the transducer out of the water, and listen for a ticking noise

      • If there is no ticking noise, the transducer is not connected or may have become defective

      • Do not allow the transducer to run for long periods while out of the water, which may damage the transducer

    • If another compatible transducer is available and known to work properly, temporarily connect that transducer to the device

      • If the device shows a sonar option and operates properly, replace the transducer

        • See garmin.com for a list of the device's compatible transducers

If no sonar option is shown, and if all other troubleshooting steps have been completed, contact Product Support.


Flashing or dashed depth readings

If the device displays a flashing depth reading, dashed lines (– –) in place of the depth reading, or no bottom return, the transducer is not able to determine the water depth. This could be caused one or more of the following:

  • High boat speeds create cavitation that may prevent the transducer from picking up a sonar reading

  • The transducer must be clear of any fouling or scratches in order to get a depth reading

  • Set the correct transducer frequency on the device:

    • Go to garmin.com and look up the transducer model, then the Specs section to see the correct frequency

    • See the device's owner's manual for steps to manually set the transducer frequency

  • Restore the sonar default settings on the marine device

Steps to restore sonar default settings

The device will restore settings on all sonar views to default. 


To restore sonar default settings on a STRIKER device:

Open any sonar page on the STRIKER press, the Menu bar icon transparent Menu button > Sonar Setup > Restore Sonar Defaults - Select Yes


To Restore sonar default setting on current GPSMAP devices: 

From any sonar page press, Options > Sonar Set up >  Installation > Restore Sonar Defaults > Yes will reset the unit to factory settings 


To restore sonar default settings on an ECHOMAP or  Legacy GPSMAP device: 

Open any sonar page on the ECHOMAP or GPSMAP press, Menu > Sonar Setup > Installation >  Restore Sonar Defaults - Select Yes


Mounting-specific troubleshooting

Select a transducer mounting type for troubleshooting steps:

Transom-mounted transducers

    • The transducer must be submerged in at least 1/8 in. of water to get a depth reading

      • If the transducer is higher than this or comes out of the water when not on plane, mount it lower on the transom

      • If the transducer must be tested when the boat is out of the water, submerge the transducer in a bucket of water

    • The transducer must be level with the water's surface

      • Installing a transducer at an angle, regardless of the degree, will result in inaccurate depth readings and bottom returns

    • If using a boat with a stepped or V-shaped hull, mount the transducer on the lowest point on the hull

      • Transducers mounted above the lowest step may experience cavitation

      • Some boats may require a thru-hull transducer if the transom-mounted transducer experiences cavitation even on the lowest step

    • If using a pontoon boat, transom-mounted transducers will experience cavitation at lower speeds than most power boats

      • It is recommended to use a pole mount, a plate, or a thru-hull or in-hull transducer on a pontoon boat


Trolling motor-mounted transducers


If the marine device has a trolling motor-mounted transducer and shows a bottom reading but no fish or suspended targets, this may be caused by either transducer placement or noise from the trolling motor.

The transducer must be mounted correctly on the trolling motor. See the transducer's installation instructions for more information.

The following steps can help reduce trolling motor interference:

    • Connect the trolling motor to a separate battery from the Garmin marine device

    • Run the trolling motor and transducer cables in opposite directions

    • Use ferrite beads on the transducer cable

    • Check for any corrosion on the trolling motor wires

    • Connect the trolling motor to a water ground, a grounding plate, or a post on the battery

    • Check the fuse of the trolling motor if it has one

      • Blown fuses can create electrical interference even if the trolling motor is still able to operate


In-hull transducers

    • The transducer must be appropriate for the boat's deadrise and correctly mounted

      • Go to garmin.com to search for the transducer and find the maximum deadrise on its Specs page

    • The transducer must be mounted in a solid fiberglass hull

      • 500 W in-hull transducers must be mounted in solid fiberglass hulls no more than 3/4 in. thick

      • 1 kW transducers can be mounted in solid fiberglass hulls up to 1 in. thick

      • The transducer will not work with cored fiberglass hulls, hulls with air spaces, or any other hull material

    • The transducer must not be mounted over any strake or other parts of the hull that will create turbulence or cavitation

    • If the in-hull transducer is in a fluid tank, check that the fluid reservoir is full and does not have a leak

      • If possible, fill the fluid tank with marine-safe antifreeze, such as propylene glycol, to cool the transducer elements


Thru-hull transducers

    • The transducer must be appropriate for the boat's deadrise and correctly mounted

      • Go to garmin.com to search for the transducer and find the maximum deadrise on its Specs page

    • If using a thru-hull pairing, check that the adapter cable is secure and has no visible damage

      • If necessary, replace the adapter cable

Related

Contact Us for More Help