The message "Transducer disconnected. Sonar turned off" on a Garmin marine device indicates that the transducer is no longer communicating with its built-in or external sonar module.

To resolve the error message:

Inspect the transducer cable for any damage
- 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
Check the cable connector head and the transducer port on the device or powered mount to check for bent or broken pins
Check for corrosion on both the transducer cable connector head and the port on the device or powered mount
- Light corrosion can be cleaned using a brush and dielectric grease
- Heavy corrosion may have extended into the cable, the powered mount, or the device itself; the affected part will need to be replaced
Check that the transducer cable is securely connected
- Use a locking collar (also known as a split connector) if present
- 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
If using a 6-pin transducer that can measure water temperature, a failed temperature sensor may cause the device not to recognize the transducer
- On Airmar thru-hull transducers with a fairing block, such as the B744V and B744VL, see Replacing the Temperature Probe in a Transducer for information about purchasing a replacement temperature probe from Airmar
- On other transducers, connect a Garmin temperature probe to correct the error
Replace the transducer

Note: If using a 6-pin transducer with the wire block adapter, installing a jumper wire between pins 4 and 5 inside the block (not on the 8-pin connector) may resolve the issue. See the adapter installation instructions for more information.