GPS Data Not Received
Icom Marine VHF Radio
Severity: MinorWhat Does This Error Mean?
'GPS Data Not Received' means your Icom radio is no longer getting GPS position data.
DSC distress calls will still go out but without coordinates — the Coast Guard sees your MMSI without position.
Voice features still work normally.
Check the GPS source: internal antenna obstruction, external antenna cable, or NMEA GPS feed from chartplotter.
Affected Models
- Icom IC-M510
- Icom IC-M605
- Icom IC-M93D
- Icom IC-M37
Common Causes
- Internal GPS antenna blocked (mounted under metal)
- External GPS antenna cable damaged or disconnected
- NMEA 0183/2000 GPS source offline
- GPS in cold-start mode after long power-off
- GPS receiver itself failed
How to Fix It
-
Check the radio's GPS source setting.
On Icom: Menu → GPS Setup → GPS Source.
Confirm whether you're using internal GPS or external NMEA input.
The fix depends on the source — internal needs sky view, external needs NMEA wiring. -
For internal GPS: clear sky view.
Move the boat to clear sky view if under a bridge, T-top, or hardtop.
Wait 2-3 minutes for the GPS to re-acquire.
Handheld VHFs with internal GPS especially struggle when held inside a boat cabin — step outside if possible. -
For external GPS: check NMEA.
If your radio is fed by NMEA from a chartplotter, confirm the chartplotter has GPS lock.
Check NMEA wires for tightness and damage.
Loose NMEA connections at the radio are common causes.
Push connectors firmly into their sockets. -
Inspect external GPS antenna.
If using a separate GPS antenna for the radio, inspect for damage, salt buildup, or obstructions.
Wipe clean.
Trace the cable for kinks or breaks.
Replace damaged cables (40-100 USD parts). -
Power-cycle the radio.
Power off for 30 seconds, power back on.
Wait for GPS acquisition — internal GPS may take a few minutes for cold start.
External GPS should reconnect within 10 seconds once chartplotter has lock and NMEA is good.
Frequently Asked Questions
Will distress still work without GPS?
Yes — DSC distress still transmits with your MMSI.
What's missing is your position.
The rescue coordinator has to ask you for position over voice (channel 16).
This is a significant safety degradation, especially in offshore use.
Fix GPS feed before relying on the radio for emergency use.
How often does internal GPS need open sky?
Continuously — once initialized, GPS needs at least 4 satellites in view at all times.
Brief obstructions (passing under a bridge) are handled by the receiver's filter.
Sustained obstructions (parked under a hardtop for hours) drop the lock.
Internal GPS is best used in radios that sit out in the open.