iOS12 GPS Accuracy is off?

Hi pandahill,

Thanks for contributing to this thread also, I've seen mentions on Twitter of this issue too, so I know it's not unique.

I didn't know 12.01 was out, but I tried the other things you mention, also without success. It does sound like we have exactly the same issue: new in iOS12, even just looking at Google or Apple Maps static I see the erratic re-poisitionng.

On my side at best I have been able to reduce the impact to my running. MapMyRun does a better job of correcting the route than Strava, but both are wrong (Strava c. 15%, MMR c.5%) - and all my long term stats are getting torched 😟

Update on my situation: after 2 weeks of painful calls with Apple and little meaningful response from engineers, they finally told me they're filing this as a hardware issue and to go to a store for a replacement phone (appointment today).

This should be a relief but feels like a bit of a cop out as I have never thought of it as a hardware issue and I have very little confidence it's really resolved. It also means they aren't fixing the underling issue that affects you and others too.

This isn't really a fix for me, it's just a substitute. I have a 256GB phone with 150GB of music and data. It is a serious hassle to resync a clean phone, and reflects badly on iOS12 that this has been made necessary on a 10 month old X.

Austin,

The fact that you could use a HKG-based carrier in China via roaming doesn't necessarily mean you weren't getting your Google services blocked - unless your data bypasses China's censorship systems e.g. by using VPN . Here is another site (dated Sep 2018) that says it is impossible to get Google Maps to work properly in China. "https://welcometochina.com.au/is-it-the-end-for-google-in-china-heres-some-alter natives-1886.html

Judging by this and the previous link I pasted, there may be some functionality but it sounds like the authorities there are deliberately messing with the service.

Whatever the case, you could try the SIM procedure mentioned above (at your own risk - for me, I had to do it while the phone was on, then restart, then re-insert). In my case, the SIM card itself was probably not the problem - it was more likely a problem with how the phone's software calibrated my position using a combination of GPS and celullar/wifi - I think the reinsertion forced the phone to re-register with the cell towers.

Also try setting your Compass app setting to True North.

These steps may not work for you but they don't take long. Worth a try...

Hi AppleQer,

Thanks for your contribution and your experiences! I installed GPS Diagnostic (whats £2.99 when I can't use a £1200 phone properly! 😕 ) and it only shows satellites outdoors, and even then it is amber, between about 50% and 75% quality and quite changeable, which seems to be in step with the erratic movement on the map even when stood still.

This is around my office, not at home, where I have the real issues running, but I assume it's the same pattern (and I'm going to Apple later before I go home, so won't get a chance to test it). I also tried your SIM suggestion before I went outside using GPS Diagnostic but unless the <60% satellite quality and movement is normal, it didn't change anything.

Appreciate the ideas however, way more than anyone at Apple volunteered.

Rob

Sorry to hear this--I've had somewhat similar problems past 6 weeks or so with OS 11.4.1 on my 6s+. Started in familiar area totally away from tall buildings, etc, with both Apple and Google maps initially placing me about 15-20 miles away from a location I visit often and had always had accurate visualization on both maps. Later, on trip to PA, had difficulty in both Philadelphia and Pittsburgh with both maps--would place us in wrong hotel (each a different one!), difficulty navigating downtown streets while walking, and poor locating for Uber pickups. Very erratic--seemed to work reasonably well during most highway travel. Tried usual resets, etc and visited Apple store where was told could be either software or GPS chip problem. Did a more elaborate reset, but not a full software change. Some better now (?), except recorded distances from usual daily walk erratic. Planned to get the new model still due to come out after first of year and had been delaying OS upgrade to wait for usual fixes, etc, but will certainly wait longer after reading these posts. Clearly, something has happened.

Hi Rob,

Did you remove the SIM while the phone was on (see the warning), turn off, then turn on, and re-insert?

Was there any difference before and after?

On GDP Diagnostic, I have four satellites showing and 60% quality when testing on the edge of my balcony, with the sky half covered by the edge of my roof but nothing immediately and diagonally in front of me. It is changeable and I get about 30m accuracy on average on the balcony, which I consider good, given the situation. When jogging outside I think I get about 5m-10m accuracy which is good enough. The trail maps that Motion X produces at the end of the jog are very accurate, right down to the particular path in a park. The main problem is time to first fix, which gets worse over time, until I have to do the SIM thing all over again- I did it first in May and then three months later in August.

Hi Austin,

Bit of a mystery, I still suspect you got some of your Google service functions blocked in mainland China, if you had no VPN access and had to channel your China Unicom data through mainland telecom systems.

If it is a problem with Google Maps itself, it is odd that you can use Google Maps with the same phone in the US, but not mainland China. I can't explain why the performance of Apple Maps in HKG was not as bad as for Google Maps - the subpar performance of both was probably due to the tall buildings in HKG, which would explain why Apple Maps performance improved in that street of 4-storey buildings in Beijing (while Google Maps in Beijing could have been affected by blocking by mainland systems).

Hi AppleQer,

Thank you for your continued input to this issue. I did exactly as you described for the SIM. I hadn't used the GPS Diagnostic before it however, so I don't know if it made a difference - as I also had 4 satellites showing of variable quality c. 60%. When I got home (where I jog) the satellite reading was same but dropped occasionally sub 50% (red).

This morning I used a different app (MapMyRun) which has also been affected (but does a better job than Strava of correcting) and I followed your instruction to first go outside and monitor picking up satellite GPS (MapMyRun helpfully has a GPS measure - it showed 2/4 bars) and after that it seemed to record accurately (no lines through buildings etc).

I don't know now if that was the SIM change, the standing outside at 6am in the cold monitoring for GPS pick up (don't want that to be the requirement every morning, particularly as this was introduced by iOS12) or something else. I'll need to try with Strava tomorrow to see if this holds, because Strava has been particularly bad (15%+ off) under iOS12 GPS.

One observation is I did an interesting experiment this morning where I also tracked the run on my Apple Watch at the same time, and it wound up with almost the same "messed up" 15% off distance and erratic route. I wonder if that is a confirmation that the inaccuracies are related to not having satellite GPS (assuming the phone app was using that).

In parallel I went to Apple as instructed by them yesterday and had a horrific ordeal to match the past two weeks on the phone with no support. They refused to honour warranty without payment due to a hairline screen crack (unrelated and 3 months older than the GPS issue). They made me stand in the store and negotiate to phone support for 2 hours.

In the end after 3 hours I got nowhere, and the whole trip I was advised to make to resolve this GPS issue, was wasted (after 5+ hours the past two weeks). It's great that there are users like you AppleQer but after 10 years my negative experience of Apple is now irreversible and once I get this GPS issue resolved, it's the last time I buy an Apple product.

I hear you, Rob. I found Tech Support on the phone to be fairly useless; they did a remote test of my A-GPS system and said it was fine. How on earth could they know as I was deep inside my home at the time?!?! And the "Genius" in the Apple Store argued the Apple Maps app was functioning fine with GPS until I reminded her that we were in the basement with an open stairwell but no view of the sky and far from any window! She didn't know the difference between a Wifi/Cellular-only based location and an A-GPS based one. The location on the map showed us in an Apple Store. Not exactly a surprise, given that the phone was connected to the Wifi of that store!

I have never tried those Apps you mentioned. Motion X-GPS works well for me, I downloaded it from the App Store, for free, I think. You might get better results with that. I use it because, like GPS Diagnostic, it gives a clear indication of when I have an A-GPS fix (blue/green globe) and when I just have a Wifi/Cellular-only one or no fix at all (both as red globes).

I am now resigned to the fact that I have to stand motionless or walk very slowly under the open sky until I get the initial A-GPS fix, and may have to repeat the SIM procedure if the time to first fix gets too long again. Once I get the fix, the tracking is very accurate. It just ***** that I paid so much for an iPhone X and yet my wife's well-worn iPhone 6S with the same carrier and iOS always gets the first fix faster.

Thanks. I'll try some of the test apps; have always minimized allowing location permission for apps. Can't be sure whether WiFi was always on in past, but some of problems have been in car far from possible WiFi . Usually is on; Bluetooth usually off, but hard to believe that would help except in very special cases. Think I'll wait to try the Sim maneuver; it's going to be a while before I seriously need accurate maps location. In meantime, will follow news of upgrades, etc and defer IOS upgrade. Plan on buying either iPhone 8 or the upcoming 10 model before a trip in March, and hope things will become clear before that. Very frustrating: during trip to London in June, had amazingly precise location while walking using Google Maps--was very helpful. Hope Apple hasn't concentrated too much on adding new features I'll never use and let some of the old standards deteriorate.

Tntoofore,

In-vehicle GPS issues with your iPhone can depend on your vehicle model. They are discussed in other GPS threads in these forums, perhaps the "iOS11 screwed my GPS" (or whatever it is called), or the "iPhone 8 GPS one, or the iPhone X GPS one, or the iPhone 6 GPS one 😉. I have lost count of how many threads there are on GPS issues. Just when I thought this issue had subsided, if not been resolved, this new thread crops up (someone on another thread mentioned it to me).

It is up to you but I would definitely want to have a working A-GPS-based function as soon as possible, especially for emergencies. To give Apple, credit, its SOS function for sending out your location and alert messages to designated friends and family is pretty good, so I would make use of it by making sure you have a working A-GPS system . Also, your FindMyiPhone function won't be much use either if your location is based only on cellular triangulation/wifi, particularly whenever you are in rural areas.

Thanks again. I downloaded GPS diagnostic yesterday, and both then and today, I get green at 75% on 4 satellites. I've started testing a bit on my local walks, and today things seemed spot on--I'll try with WiFi turned off tomorrow . I'm not sure what happened just before and on our recent trip. Certainly, part of it was the rental car--had problems unlike any before on personal or rental cars (we were given a Jeep Renagade rather than our specified car--never again for many reasons!), but we didn't drive the car up to our hotel floor, where I got positioning suggesting we were in a different hotel with both Apple and Google maps, and we weren't connected to a car when I got a start point 15-20 miles from where we were a week or so before the trip. Perhaps the recent software reset has done more good than I realized (or perhaps there is an intermittent problem that will resurface). I'll keep testing, but will also defer upgrading IOS for now. Prior to all this, I had had such good performance with location on the maps that I had not realized the problems others have been having at times and had taken map performance for granted (except that Google refuses to change the numbering on the road to our local lake campsite, although Apple has corrected their addresses in the area.--but, that's not a GPS problem.) Thanks for tip on SOS; I'll look into it. Have also been interested that Apple has been working to make location better for 911 calls. I'd like to get rid of my lake cabin land line, but have hesitated because of fears that 911 might not work well.

I have now done a full restore of the phone back to new (not restoring the backup)

With no apps installed apple maps is still showing the incorrect location, and only refreshing every few minutes.

This makes it impossible to use navigation in the car, and all other location services are inaccurate

I have logged a support call with apple, they were lovely to deal with. They went through their diagnostic tests over the phone.

No issues came up from their end, they are now escalating the issue to their engineers to follow through.

I'll wait and see what the outcome is.

They did the remote diagnostic test over the phone with me too, but I was inside my home at the time, so I don't see how that could have tested the GPS chipset properly. I found the tech helpline not much use. Best thing is to take it into the Genius Bar.