iOS12 GPS Accuracy is off?

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.

Funny you should say that. I am now using iOS12.0.1 too.

Yesterday evening, I got an initial location fix that took way less time than usual. And I think the day before was pretty good too- certainly not bad enough for me to get irritated and remember.

(My accuracy after first fix has always been good, except for a one or two occasions when the issue first started.)

This may be yet another fluke or false dawn.

Time will tell.

BTW, I now update iOS via iTunes and USB instead of via Wifi. iTunes downloads the full package and does a self-validation before installing. The Wifi method doesn't according to these and other sites.

https://www.gottabemobile.com/ios-updates-over-the-air-vs-itunes-update-whats-th e-difference/

Updating iOS using OTA vs updating through Itunes | AppleVis

AppleQer wrote:

My issue was never with accuracy, as long as I got the initial fix.

The problem was with the time to first fix.

The iPhone X still seems far more fussy about me remaining motionless initially

Interesting - there really could be something to that.

I was always on the move when I hit go, either walking during a warm up countdown, or literally starting to run and hitting go - I didn't even know if I had a GPS lock (and didn't need to check before iOS 12 as never had problems).

It's only been in the past 2 weeks carrying another GPS device for comparison, that (due to IT'S requirement) I am consciously standing still watching for IT to report a GPS lock, more than enough time for the iPhone to be happy.

It still relates to a change in iOS 12 but your point is well made, standing still obviously seems to help it out (not great with the UK temperatures tumbling at this time of year). Will do more tests before allowing Apple to close my case.

I just found in a Twitter post the report issue function in the Apple Maps app, maybe if we all do this we may get some action from apple?

Branta_uk wrote:

You're in Hong Kong, land of the high rise and urban canyons. You can expect poor or unpredictable GPS performance

And I'm in central London and have the same issue. Also the original contributor, like me, reports this as occurring after the update to iOS12, so I expect that they, like me, had no problems with GPS performance prior to this update.

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.

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.

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.

pandahill wrote:

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.

They may be lovely to deal with but they are utterly powerless in respect of these GPS issues. I've now been dealing with "Senior Customer Advisors" for 3 weeks, I have had to start keeping logs and names - 5 different senior advisors and over 10 hours solid spent trying to resolve this issue - with zero admission of an issue and no resolution.

As "AppleQer" says, the diagnostic is meaningless. I did that and uploaded about 300mb of data to them and none of it counted for anything (I was also asked to do a screen recording of maps while walking outside). The engineers followed up with inane questions and eventually tried to palm it off as a hardware issue, which Apple won't address.

I've been off this thread for a week because it's all too depressing. I even had to send an 8 page slide deck containing all my evidence of this issue - I included lots of GPS tracked maps from before and after iOS 12 update, which clearly showed the problem. I even included a load of tweets and linked to this thread. Still Apple are "investigating".

They have no interest in resolving or acknowledging. In the meantime out of desperation I had to buy a GPS watch. It has been an education as GPS accuracy is clearly volatile even on other devices, but after several tests, it is obviously only the iPhone that is permanently out of whack - the watch has some tricky spots, iPhone GPS is always off.

I hope neither the new devices nor IOS are going to permanently require a still period or longer time to register the GPS signal--my use is primarily in driving and not infrequently my wife, who is not very computer confident, is asked to start the device as we are driving along. I had thought my recent problems were over after a software reset followed by several trips of +/- 50 miles with good accuracy and several walks with apparently good accuracy (I don't use a tracker). GPS diagnostic was showing ~75% indoors and near 100% outdoors on 3, slightly less on 4th satellite.

However, I then made a 7-8 mile drive into an area strange to me, and on exiting my driveway, location seemed about 20-30 yards off the road, with arrow indicator pointing off to side. This continued for about a mile, with arrow direction meandering around rather aimlessly. Then, luckily before I entered "unknown territory", the problem cleared up and the map (Google) worked well for the rest of the trip and return. Finally, yesterday I checked GPS diagnostic and got NO satellite either indoors or indoors and both map programs were 1-2 blocks off in indicating my home location with WiFi off. At that point, I figured OS 12.1 couldn't make things worse, so upgraded--unfortunately, hadn't noted the comments regarding using WiFi vs iTunes. In any case, now get ~75% on "4 or more" satellites indoors, near 100% outdoors. Google maps accuracy so far seems good, GPS D says 17 feet outdoors, 33 feet indoors. Takes ~2-3 seconds for GPS D to register outdoors, 5-6 indoors. General operation of phone seems a bit crisper overall with 12.1, but that's hard to judge for certain.

I'm hoping this will last until I'm ready to trade--will need good accuracy to walk around foreign cities, use for "Uber-like" transit, etc in late March and will need to make decision on going from 6s+ to either 8+ or XR before then. Still remember the rather incredible accuracy I got in walking around London in June before all this started, but suspect density of WiFi there probably helped.

Update on this.

After awful GPS accuracy with iPhone X under iOS 12, as reported I got a small improvement in October but certainly not back to the accuracy I experienced before iOS 12, and only on certain days (implying it could well be an acquiring GPS signal issue).

Since then I have tried (for running GPS purposes) the Fitbit Ionic and Garmin 635 (both standalone GPS watches that don't require a smartphone) and had poor GPS and other issues on both. I then held my nose after all Apple's problems and got a Watch 4.

The AW4 has been flawless for GPS - I'm amazed. Not one mistake the past 3 weeks, and I'm not spending any time to acquire a signal either (it's often 5.30am and 3 degrees so I don't hang about). So it's all the more unusual that GPS in the iPhone X is way off.

Surely GPS tech is comparative between AW4 and iPhoneX and if anything more high powered in the smart phone. This leads me to be more certain this was a software issue introduced with iOS 12 on the phone (although Apple continue to refuse to address it).

Anyway, since then I've continued to do a few more tests with the iPhone X as I still get hopeless GPS even with local search apps or things like Citymapper. I use a standalone GPS tracking app ("TrackMe") and the tracking, anywhere in London, is a mess.

Finally, today for separate reasons, I carried my iPhone during an AW4 run. Amazingly, first 1km on the watch reverted to the awful accuracy (c.10-15% out). I guess if the phone is near it uses its GPS. I turned the phone to Airplane mode and GPS was fine.

What more can I do to prove to Apple that GPS issues occurring on the iPhone relate to its software, and its software alone....??!!

I have the same issue in Australia. iPhone6 running iOS12

It is an issue across all my apps that use GPS.

GPS worked perfectly under iOS11.

When walking in open space the GPS would seem to refresh/connect infrequently with maps open.

The location arrow in the status bar would switch from solid (GPS active) to hollow at maybe minute intervals

So much so that while navigating I could drive 3 blocks past a turnoff before the GPS navigation realises to tell me to turn around.

Walking is the same you would easily be 20-40m away from the location the GPS is reporting.

Your location would stay static and then refresh every minute or so, exactly the same as Rob2775 reported with his running eratic route.

Apple please fix.