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GPS about 30m off

Edwin
6 months ago

I have noticed this twice now. After using my GPSmap 67i for a few hours the gps is at once way off.

We went for a little walk this evening to find a cache. The gps worked fine until the last waypoint. We were on the right spot and according to the gps we were 30m away from that waypoint.

In the hurry of that moment I didn't notice the fault right away, but being home in my backyard I see the gps is still way off.

Multi-GNSS is selected and Multi-Band is on. According to the Satellite page  there could be a variation of 1.8m. On the map I can see the gps is at least 30m off.

Switching the device off and on solves it directly. I had the same experience yesterday (not caching or walking at that time, just playing with this new toy at home), so it is not just a one time glitch.

I wonder if someone else has this experience as well and I hope someone can tell me I can solve this behavior by myself.

Regards,

   Edwin.

  • 0 1 month ago in reply to scubajorgen

    As I already wrote above, I have the same problem. The Garmin support told me, that this is a normal behaviour. As I cannot belive that, I talked to my retailer to replace the GPSmap with a new one and he did.

    Then I did the same test with a new GPSmap (without updating - Firmware v6.91) and it worked without problems over some days, no drift!. Then I updated the device to v7.60 and it still worked over a longer period. BUT: after updating it to the current v8.90 I instant had the problem again :-(

    Starting with v8.xx, Garmin also updated GPS firmware version from v2.46 to v11.02. So I think that maybe it is a bug in the GPS firmware?

    Sadly it is not possible (as far as I know) to downgrade the GPS to an older firmware version :-(

  • 0 1 month ago in reply to Chris
    Chris said:
    As I already wrote above, I have the same problem. The Garmin support told me, that this is a normal behaviour. As I cannot belive that, I talked to my retailer to replace the GPSmap with a new one and he did

    I won't accept that (i.e. the response of Garmin) Rage 500 euros down the drain

    Praise your retailer, however the device doesn't seem the problem!

    Chris said:

    Then I did the same test with a new GPSmap (without updating - Firmware v6.91) and it worked without problems over some days, no drift!. Then I updated the device to v7.60 and it still worked over a longer period. BUT: after updating it to the current v8.90 I instant had the problem again :-(

    Starting with v8.xx, Garmin also updated GPS firmware version from v2.46 to v11.02. So I think that maybe it is a bug in the GPS firmware?

    This is really interesting information!

    I find in the release notes from 8.30:

    • Improved GPS Performance.

    That presumably is the culprit then based on the info of Chris.

    Kids, don't try this at home!

    I find on the gpsrchive a firmware archive for the GPSMAP 67, a.o. 7.60

    It contains a manual to downgrade the firmware.

    Manual Updates

    NOTE: Loading older firmware versions will clear all user data from the device (remove micro SD card if present).

    * Download and extract the desired *.GSP firmware update.
    * Rename *.GSP to GUPDATE.GSP.
    * Connect the GPSMAP 67 to your computer and enter MTP Mode.
    * Copy GUPDATE.GSP to [GPSr]\Internal Storage\Garmin\GUPDATE.GSP.
    * If loading an older firmware version, create a force.tmp file in the [GPSr]\Internal Storage\Garmin\ directory.
    * Disconnect and reboot the GPSMAP 67.
    * When prompted to install the new firmware version, select 'Yes'.
    * The GPSMAP 67 will restart automatically after the firmware update is complete.

    Let's see if we can downgrade (until Garmin fixes the issue...).

    The risk may be to brick your device, warranty void, lethal accidents, etc,etc which I am willing to take Smiling imp

  • 0 26 days ago

    I downgraded the firmware to FW 7.60 (GPS FW 2.46). However this did not resolve the problem.

    I wrote a detailed report on my blog.

    Note: what you see in the images is that when you start moving, the coordinate seems to converge to the real location.

    I got a message from Garmin Support: the handed the issue to a tech team and asked for more information.
    I hope they resolve it.

  • 0 10 days ago

    Update

    • When you leave the device stationary under less than ideal condition, the indicated location as is logged starts to drift right away, with potentially large deviations  (>100 m)
      Sometimes the device recovers when you start moving, sometimes a substantial residual error persists
      Only way to let the device recover is via a power cycle

    • I mailed and called Garmin Support, provided information, report, photos, etc, etc. to their tech support
      Twice they pointed to the FAQ 
      Their reaction indicates that they don't understand the problem.
      I told them that this is highly disappointing, that I give up and buy another device.
      Hope they see the light one day and solve the problem...

  • 0 5 days ago

    Update:
    I also contacted Garmin Support US (previous contact was with Garmin Support Netherlands). They indicate the behavior is 'by design'.
    I am not going to put more energy in it and won't use the device.

  • 0 5 hours ago in reply to scubajorgen
    scubajorgen said:
    When you leave the device stationary under less than ideal condition, the indicated location as is logged starts to drift right away, with potentially large deviations  (>100 m)

    I do not understand what is this all about. I do not know anything else then this for years, not only Garmin products, but other simple gps devices. When I put such device on top of a high house, meaning full sky view, such irregularities I am experiencing all the time jumps up to 400m around. With the current garmin devices which are operated together with a phone, there is also some interaction between the gps rx in the device and position calculated by the phone. I had some jumps of few km when on the sea on a cargo ship and suddenly, near the coast, the phone calculated its own position and this landed then on the explore website.