Garmin GPS Watch needs to be synced every week - Expired CPE/EPO file causing issues.

harshbdmmaster718 on 11/01/2023 - 18:46
Last edited 12/01/2023 - 17:20

TLDR: Syncing my Garmin watch with the phone app once a week is not enough for the watch to keep time properly. It lost 9 minutes in 7 days. It lost enough time in a week to throw an infinite error when acquiring GPS signal causing watch to freeze.

I know I left a short positive comment on a recent deal, but a few months in I'm now experiencing some downsides.
(Edit: More like things I didn't know about using a GPS watch now that I have learned about the issue)

Noticed for two weeks, once a week my Garmin GPS watch will not sync with GPS ever.
Both times in an open space standing still and no matter how long it never acquires GPS signal. While normally it is almost instant.

This also results in the watch freezing up and requiring a hard restart by holding the button down for 15 secs.

It took me until the second time the GPS issue happened but I noticed the time was way off on the Garmin. Showed 6:11pm when phone showed 6:20pm. So the watch lost 9 minutes in a week.
This is the most terrible timekeeping I have ever experienced, is this completely normal? Are GPS watches using the worst timekeeping systems ever invented?
Freezing watch was causing majority of time loss.

Anyway the whole point I got this watch is to use it standalone since GPS is onboard. But how can you rely on it without syncing to the phone regularly?

Electrical & Electronics Garmin Smartwatch

Comments

  • harshbdmmaster718 on 11/01/2023 - 18:56

    If it continues to fail, I will just use it for NFC pay only. Hopefully it can keep time with that use.

    If not worst case scenario I will send it back to Amazon.

  • bargaino on 11/01/2023 - 19:20

    9 minutes in a week? There is a lot more wrong with it than just not connecting to GPS. Can't you return it?

    • harshbdmmaster718 on 11/01/2023 - 19:25

      I just realized something after coming back to the post.

      I mentioned the watch freezing up after a minute or two or not being able to lock onto GPS. But I think the freezing of the time must be happening sooner.
      I regret not fully checking the time right before attempting to start an GPS activity, but the thing is I use it for NFC pay and GPS tracking only. So I just threw the watch on and started the activity without really paying attention to the time before hand.

      So what I think is happening now is, the watch is drifting time only a minute or two after a week which is enough to cause errors when it's attempting the get the GPS signal.
      Upon this error I think the entire watch starts to freeze in the background, but the watch is still fully responsive I can tap on it to wake the screen and even go back in the menu and retry starting the same activity. But after about a minute the entire watch freezes, it becomes unresponsive to taps or button presses. The entire screen stays off and the watch needs to be hard restarted. If I remember correctly a few minutes did pass after attempting to get GPS signal lock to hard restarting the watch. This amount of time must be making up majority of the time loss (if the time was frozen in the background).

      • AustriaBargain on 11/01/2023 - 19:32
        +1

        Return it and get a better watch.

        • harshbdmmaster718 on 11/01/2023 - 19:34

          Honestly I got a great deal on it. Not the $99 all time low, but $130 after using the Amazon pick up point code.

          Everything has been fine until recently, I was just using it for NFC pay. I didn't notice it losing time in the first few months of ownership, but then again because it was new I was syncing it semi regularly just to get a feel for the app. Tracked the occasional GPS activity. But once I started using GPS almost everyday, this weird issue has crept up.

          But you are right, if I can't fix it by using the manual GPS time sync command every 3 days and keep it running without syncing it to my phone. It's going back.
          (I am thinking here. That's what the GPS time sync shortcut is for, for people who don't sync to their phone. In the beginning I removed it from the shortcut menu because I thought it was redundant - user manual says it does the time sync every time you use GPS)

          Honestly bizzare though that a watch with GPS onboard has bad timekeeping. Unless Garmin expects it's customers to sync their watch to the phone every single day, in which case most customers would not notice the timekeeping issue.

  • Chridim on 11/01/2023 - 19:24
    +3

    There is obviously something wrong with the watch, why don't you contact garmin support? Isn’t it still covered by warranty?

    • harshbdmmaster718 on 11/01/2023 - 19:27

      Honestly it's firmware and software is fully updated, and has been working fine until I started using the GPS feature.
      I added to my post in a comment above, I think the time drift is actually less than I first assumed. But the small amount of time it is losing (maybe just a minute or two) is still enough to cause GPS signal locking issues and that results in a freezing of the watch.

      I quickly read a few posts on watch forums where I am not alone in the bad timekeeping of Garmin's. It seems like it's only really noticed by some, maybe people who do not sync the watch to the phone after every activity (every day).

      • Quantumcat on 12/01/2023 - 00:26

        That's not a good reason to not contact support. Something might be wrong with the watch itself, not just the software.

        • harshbdmmaster718 on 12/01/2023 - 16:49

          Yeah sorry it was early on. I only caught onto it actually being a recurring issue yesterday after 6pm.

          I think it is reasonable to want to attempt to figure it out yourself before having contact support be the first step.
          Didn't need to contact support via email or phone in the end. I was able to identify the issue with the resources available online.

  • bdl on 11/01/2023 - 20:10

    What model is it?

  • ozwog05 on 11/01/2023 - 20:22

    Have you tried performing a factory reset since last updating it? (after backing up activity data, if applicable)

    • harshbdmmaster718 on 11/01/2023 - 20:24

      No. But it's almost a brand new watch. Got it at the very end of last year. Do you think doing a factory reset is really necessary??

      Even if I could resolve the issue with a full reset, I would not be happy with doing it every 2 months just to keep the watch working properly.

      I will try the manual GPS time sync shortcut first. Because as far as I know after hard resetting (15 sec button hold) and syncing with phone, the watch works properly again. It's just after too much time drift after a week it causes the weird behaviour described in my post.

      • ozwog05 on 11/01/2023 - 20:32

        Let me put it this way. Basically any device I update, if I can factory reset it afterwards easily with minimal backup/restore I will, as I've seen it occur enough times where an update will result in weird bugs/glitches or reduced performance, but that's just me.

        • harshbdmmaster718 on 11/01/2023 - 20:36

          Yeah fair enough. I will try the GPS time sync first see if I can avoid doing the factory reset process.

          I am trying to give Garmin another chance here. Because they must have designed the watch to work in an off grid camping/trekking scenario with no mobile data. That's what I assume the GPS time sync shortcut is for when you can't sync with the phone.

          • Quantumcat on 12/01/2023 - 00:27
            +1

            @harshbdmmaster718:

            I am trying to give Garmin another chance here

            Yet you're not willing to contact their support. How are they meant to know about this chance you're giving them to be able to respond to it?

    • harshbdmmaster718 on 13/01/2023 - 16:12

      You were right by the way. Factory reset was the fix for me.
      Before I did factory reset probably due to the watch freezing twice already, syncing with phone or PC would not update the CPE file and the watch still showed CPE expired after syncing.

      When also plugging it in via USB cable, I got a message to update the watch firmware and together with that a message told me the watch storage was completely full.
      This basically told me it was a serious firmware issue and that I had to do a factory reset.

      So it's quite clear when the CPE expired on the watch and it started manually searching for GPS satellites the watch would continuously write data to the storage memory until it filled up and froze the watch.

      I double checked how much memory the watch has after the factory reset and it's a measly 15MB total with 7 to 8MB free. Maybe Garmin cut it too close here and cheaped out on the amount of memory. I hadn't added any music files or connect IQ apps by the way so the watch should have had enough free space while I was using it until now.

      I set it up with the bare minimum changes this time. It was a bit of a pain to add NFC pay, set my Activity data fields and set all the settings to my preferences so I hope I don't have to do it again anytime soon.
      If firmware bugs keep happening and the watch requires a factory reset regularly I think I will have to return the watch.

      • ozwog05 on 13/01/2023 - 18:27

        Result. This reaffirms my faith in why this is my go-to method haha. Glad I could help.

  • Craze on 12/01/2023 - 11:57

    I got the same Venu SQ from the JB-Hifi $99 deal. GPS stopped working a few months in so I returned to JB for a replacement. Admittedly I don't use GPS daily and I sync it 1-2 times a week and haven't had issues so far. Fingers crossed just a faulty unit so I suggest you get one too!

    • harshbdmmaster718 on 12/01/2023 - 16:23

      "Fingers crossed just a faulty unit so I suggest you get one too!"

      Pretty sure it's not faulty. It's working as designed. Figured it all out on my own thanks to the internet last night. About to post a comment explaining how the GPS works (and what updates it requires) now.

  • harshbdmmaster718 on 12/01/2023 - 16:47
    +1

    Alright I figured out the issue. Thanks to online posts including Garmin's own support information pages and forum pages and also an old post by DCrainmaker.

    First of all I learned modern devices which acquire GPS signals quickly, rely on a data file which is referred to as CPE or EPO.
    It's a file that's released on schedule which tells your GPS chip what satellites to connect to, which makes the GPS lock much quicker to acquire.
    Without this file the GPS chip has to manually choose all nearby satellites (I don't know how many satellites are required usually I am guessing 10 to 15) which means it can take many minutes to acquire a GPS lock.
    This explains me standing in the same spot for 10 minutes and not getting a GPS lock.

    So the place that started this bread crumb trail was of all places youtube. I was typing in my symptoms and came across a video explaining CPE files and GPS.
    As instructed I went to my watch's Settings>System>About and scrolling down through all the regulatory info I finally found the CPE text, and on my watch it showed "CPE Expired".
    There are two things it can show, CPE Current (up to date) or CPE Expired (expired so useless).

    As stated here on Garmin support, these CPE/EPO files are updated every 3 to 14 days. https://support.garmin.com/en-GB/?faq=CevbI1mlnV2SejYAaOQZ29
    They also explain how the CPE/EPO needs to be synced onto your watch.
    1. Sync with Bluetooth to Phone (Garmin Connect)
    2. Sync with USB cable to Computer (Garmin Express)
    3. And this extra one is from a Garmin forums post, but if either option 1 or 2 is not available to sync you can do it manually by starting a GPS activity leaving your watch off your wrist outside in the same spot for 15 to 20 minutes and it will update the CPE/EPO. (Important - the more you move your watch the longer it takes)
    Reference: https://forums.garmin.com/sports-fitness/running-multisport/…

    Also in this dated article by DCrainmaker, he explains how 1 week is the most common update cycle for CPE/EPO files on the most common GPS chips.
    https://www.dcrainmaker.com/2016/03/why-your-garmin-gps-is-b…
    "But these files don’t last forever. Instead, they’re like Snapchat in that they’re only good for a certain time period. The period differs from company to company, and sometimes product to product. Usually they range from 3-14 days, though with most at about the 1-week duration."

    I know that the most recent Garmin's use Sony GPS chips, so I think the update cycle is the common 1 week or 6 days which lines up with the cycle of the issue I am having.
    (I just checked when I lasted synced the watch with the phone and it was exactly 6 days ago, so the CPE file must have expired and caused the GPS issue)

    I still have to find out if the CPE file is on it's own cycle, or if you get 6 to 7 days of "CPE Current" from the time you sync.

    So my conclusion is, the time drift or loss of time on the watch was not as dramatic as I first thought and not the actual cause of the GPS issue (I know GPS satellites require extremely accurately synced time to function so I assumed the time drift on the watch was the cause).

    And this is what I didn't know about GPS watches.

    GPS watches need to be synced with the phone at least once a week (a lot quicker and easier than doing it via GPS by leaving the watch outdoors for 15 to 20 minutes) to keep the CPE/EPO file for the GPS chip current. There is no way around this it's just how these GPS chips work. This must happen all automatically via WiFi on GPS chips in smart phones that's why you don't have to bother learning about CPE/EPO files.

    In my case the freezing of the watch seems to be triggered by an expired CPE, which forces the watch to start searching for satellites one by one manually and the watch does not like that. It is likely a firmware bug from the most recent update, but I will do a factory reset to see if that helps.
    The watch expects you to have synced within a week and have the CPE current.

    • Craze on 12/01/2023 - 21:35

      Wow thanks for the detailed write-up, appreciate it! Maybe that's what happened to the first watch I had- an expired CPE but obviously didn't know at the time. Actually to further elaborate on my issue earlier- it wasn't actually tracking speed and distance, which I'd think is linked to GPS. From memory it happened shortly after I did a software update on the watch so perhaps was a glitch.

      • harshbdmmaster718 on 13/01/2023 - 18:57

        Yeah I mean I heard some things about Garmin's having buggy updates.
        But the Venu SQ is a 2020 model I believe. So you would think they would have solved most major issues by now.

        It's good that they are still releasing updates, I think since I bought the watch I have updated it via PC 3 times. But I expect updates to fix things not break them.

        Anyway maybe my use case of the watch is a bit unusual (e.g. didn't plan to sync the watch every week, I just glance down at the GPS map summary on the watch which is good enough resolution to show how accurate it is), so I am in a small minority of customers who experienced these odd issues.
        My plan was first to use the watch for NFC pay only. Got great battery life that way with HR on (required for wrist detection) but activity tracking off. I tested it lasted 15 days before reaching 50% battery. That's what I had planned and it was great only having to charge every 2 weeks.
        Then I gave away my old Fitness tracker to someone else and decided to start using the Venu SQ for some GPS activities. That's when things started going south.

  • harshbdmmaster718 on 18/01/2023 - 16:58

    It's been 7 days since (11th Jan) I updated and Factory reset the watch so it showed CPE current.
    I deliberately wanted to let the CPE expire again to confirm the CPE schedule. It was CPE current yesterday and now showing CPE expired today so expired on the 18th (I think after midnight last night).
    So the CPE needs to be updated every 7 days for Sony GPS chips in recent Garmin watches. And my conclusion is the CPE file lasts 7 days from the moment you sync the watch/successfully update the CPE.

    Here is the start of another hiccup. Syncing with the phone (Garmin Connect App) did not update the CPE file it still showed as Expired. Next I tried the GPS time sync from the shortcut menu, with the watch off my wrist and facing the sky in the shade it acquired GPS within a few minutes and was finished almost instantly, but no CPE file update. (this probably just syncs time and doesn't do CPE, I just wanted to try)

    Next I tried leaving the watch facing the sky and ran a GPS activity for 25 minutes to try the "off grid" CPE update method. GPS signal locked on within a few minutes compared to the endless wait time if it was on my wrist with slight movement, but still no CPE file update after finishing and saving the 25 minute long activity.
    Weird. Either this method doesn't work, or I need to wait even longer (maybe 30 to 40 minute activity) in Australia/current satellite positions.

    Also worth mentioning the watch did not freeze up on me after doing all these tests. It seems like as long as you keep the watch perfectly still (off your wrist) and allow it to get a fast GPS lock the watch handles itself without any issues.

    So finally the last straw I plugged the watch with USB cable into the PC and Garmin Express software. I was really worried I would have to reset the entire watch again because the CPE file wouldn't update, but after syncing and updating "Change Logs" with Garmin Express success! The CPE is now showing as Current.

    So what I will test for the next week is to not let the CPE file expire. I will try to sync the watch with the phone (Garmin Connect App) via bluetooth on the 6th day from today. I am thinking maybe just maybe, the phone sync method for updating the CPE only works if you do it while the watch is still showing "CPS Current".
    I'll be back in a week with the results.

    • harshbdmmaster718 on 30/01/2023 - 18:51

      Sorry for the late update. It's been over a week.
      And that's because I cut it a little too close and let the CPE expire again.
      I was meant to sync it to the phone the day before to try to see if it would update the CPE if I didn't let it expire.

      Anyway in it's current state, I have to connect the watch via USB cable to Garmin Express in order to update the CPE every 6 days. Kind of a PIA.
      Also there have been like 2 Garmin Connect App updates since a week ago, and they had no effect. Watch will not update CPE over bluetooth with phone.

      • harshbdmmaster718 on 06/02/2023 - 17:29

        6 days later now.
        Update. After syncing with Garmin Connect via phone on the 5th and 6th day after syncing with Garmin Express via PC, the CPE still expired (and one more time after CPE expired just for testing sake). So letting the CPE expire is not the issue. Regardless of what I have done, with the Garmin Connect App via phone the CPE file will not update.
        And this is on the latest watch firmware and the App has had about 5 or 6 updates in the last few weeks, none of them addressing the issue where the CPE file does not update via the phone (when Garmin support article specifically states it is one of the methods the CPE file will be updated).

        So every time the CPE expired, I have to plug the watch into the PC with USB cable and update it with Garmin Express software. Which also sometimes does not work. Garmin supports response? Go into the RemoteWS folder and delete the CPE file on the watch, then run Garmin Express again. Which worked, but does not fix the glaring issue at hand which the fact the CPE won't update via the phone.

        If I had bought this watch primarily for exercise activity GPS tracking, I would have returned it by now. Luckily my primary use is NFC pay, and GPS is only secondary and more of a thing I thought I would try out.

        • harshbdmmaster718 on 06/02/2023 - 20:18

          I would also like to add that it was my misunderstanding to begin with, that a GPS watch would work standalone and not really need to be constantly tethered to a phone or synced regularly with a PC.
          Since then I have learned about what a CPE file is and that with a Garmin watch with Sony GPS chip that file needs to be updated every 6 days with whatever method that works.
          Also you know what would really be a step forward Garmin? To give the user the "option" to tap and update the CPE file in the Garmin Connect phone App. Maybe then it would actually have a better chance to work.

  • Craze on 09/02/2023 - 16:55

    Off topic, but has your Garmin watch just crap itself OP? I had a software update pushed through late last week and was giving it a bit of a clean 2 days ago and it just went all crazy. Screen would not respond and have also had buzzing noise intermittently.

    I would send you a PM but you don't have that enabled.

    • harshbdmmaster718 on 09/02/2023 - 17:35
      +1

      Off topic, but has your Garmin watch just crap itself OP?

      No hasn't crap itself just yet. I was able to find the cause of the watch freezing and needing to be hard restarted, which was trying to acquire a GPS signal (which it never could because the watch would freeze) with an expired CPE(EPO) file which expires every 6 days on the Venu SQ.
      I discovered when manually searching for GPS satellites the watch basically fills up it's onboard memory and freezes itself.

      The problem I have is the watch is not updating the CPE file as Garmin support claims it should by syncing with Garmin Connect App (phone).
      https://support.garmin.com/en-GB/?faq=CevbI1mlnV2SejYAaOQZ29

      Honestly I didn't buy the watch for GPS, but thought it would be nice to try. Turns out GPS on watches doesn't quite work like it does on a phone and requires this file to be updated on the regular cycle. But I did not expect to plug the watch into the PC software every 6 days just to keep GPS working.

      Anyhow if I just use it for NFC pay I don't have any issues.

  • harshbdmmaster718 on 04/03/2023 - 20:26

    Alright just another follow up.

    I am just using the watch for the past few months without going out of my way to ensure the CPE file is up to date.
    If I need to update the watch's firmware (takes forever by phone app with no real progress indication) I just plug it into the PC and simultaneously the CPE file update is part of the process so that's the only time the CPE gets updated.

    On cloudy days I always record an activity by choosing the Run activity which I have set GPS to "off" so it calculates distance by using stride length and step count data. I found it's pretty accurate because my walking stride length is longer than most people so I found the Run activity stride length calculation is more accurate than the Walk activity stride length calculation (I tested both without GPS and came to this conclusion).
    I have a habit of doing this because on cloudy/rainy days often the GPS signal is weaker and slower to connect/less accurate data is collected/battery drain is more.

    So because I record the Run activity without GPS on cloudy days and it's accurate enough, once the CPE file is expired I just use that non GPS mode to record my walks. Next time when I need to update the watch firmware and the CPE file is updated, I use that opportunity to record a few GPS walks to add to the Garmin App data.

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