It’s getting increasingly harder and risky to unlock the iPhone. Proof is with the recent release of the UltraSn0w unlock for iOS 4.2.1, 4.1, and 4.0.2, which require you to update your iPhone baseband to 06.15.00 in order to be able to unlock.

As reported by many unlockers and officially confirmed by the Dev Team, there is an issue with baseband 06.15.00 which might cause your GPS to not function properly, if at all. While some users are able to get their iPhone GPS to work, others are experiencing problems…

Unlockers have been reporting mixed results about GPS functionality at 06.15.00. Until we can track down what differentiates those who retain GPS vs. those who lose it, be conservative and assume you’ll lose GPS at 06.15.00. As we work on finding the cause (and possibly a fix), please report your personal findings in our comments section. (Update: early indications are that while 06.15.00 is capable of GPS, it will require some further hacks. But please still be conservative and assume you will lose GPS at 06.15, in case the hacks don’t work).

Hardware designer ThreeFlight2005 explains in a rather technical document why this problem is happening:

The iPad uses the same, Infineon X-GOLD 608 PMB8878, baseband chip as the 3G and 3GS. (The iPhone 4 uses the Infineon X-Gold 618 PMB9800 Baseband chip) This is the major reason that substituting the iPad Baseband has allowed an unlock. The iPad Baseband is compatible with the PMB8878 Baseband chip; however, it probably does not contain the corret Memory Map and Read-Write commands to interface with the old PMB2525 GPS Chip.

So in short, it’s a compatibility issue. The hardware is compatible. Now they just need to make the software compatible.

The Dev Team and others are currently working on this issue. In the meanwhile, if you don’t want to lose your iPhone GSP capabilities, you may want to stay away from this baseband update to 06.15.00.

  • Jacob

    I think its a bit too late for that warning….

  • Doug

    Maybe all the people who were pressuring for an unlock will stop whining now that their desire to have everything they think they’re entitled to NOW has meant that something not entirely tested has been released and lost them important functionality as a consequence.

    I kid…they’re just going to complain at the Dev Team for releasing substandard code and give them more grief than usual of course. 🙁

  • Irha

    How about putting some more context into these reports? Is 06.15.00 relevant only to the iPad? If the articles started with the device(s) that it is relevant to, the readers can decide whether it is of interest to them or not.

  • J dubular

    @Irha ….. you´re an idiot.

  • J dubular

    Sebastian, not sure if you´ll see this but do you recommend upgrading the baseband for a much needed unlock or wait and see if a “nicer” option makes itself available? and on an off topic question (couldnt find it in forums) does upgrading the fm ever upgrade the bootloader? any info from anyone would be much appreciated.

  • Monauwarul Islam

    I unlocked my iPhone 3GS 4.1 using ultrasn0w 1.2 with upgrading bb 6.15.00. Now I have issue with the GPS and it’s not working. Could you please solve this problem and help me out of this. Thank you.

  • Monauwarul Islam

    Help me about the GPS issue after unlock iPhone with bb 6.15.00

  • Morfino

    I’ve been waiting for this fix before I upgrade my iPhone 3G to 4.2. Any news?? Thanks.

  • callum

    does upgrading your ios automatically change your baseband ?

  • chris

    i’ve upgraded to 6.15.00 with 4.2.1 and am NOT experiencing any problem with my GPS.

  • cclaudiu

    same prob here, have updated iphone with 4.2.1 and bb 6.15 and i am not able to catch up any gps, it stays in “looking for gps signal” like a lot of time, has some fractures while finding the signal and in 1 sec it looses it; google maps – OK, iGO – NOK
    Iphone 3GS after 40 week the case;
    I tried a lot of things in solving the GPS, like resetting the network, warnings, installing the gpsserial, xgps and reseting the iphone… and nothing…
    Downgrading from 4.2.1 to 3.1.3 needs the SHSH bulbs??? mandatory…. this i understood…
    any news greatly appreciated…

  • charly

    GPS DEAD. Thank you DEV-TEAM 🙁 3GS old bootrom upgraded to 4.2.1 (bb 06.15.00 redsn0W ultrsn0w)

    I’m upset against the Dev-Team (the “dev-team blog” admin censored this message. I simply remind the truth to people).

    I have 2 iPhones 3GS old boot rom (baseband 5.15) that I upgraded to 4.2.1, jailbreaked & desimlocked using redsn0W & ultrsn0w (Now baseband 06.15.00).

    Yes, there was a warning concerning baseband 06.15.00, when 4.2.1 was released with redsn0W & ultrsn0w.
    This warning simply stated that you wouldn’t be able to downgrade your baseband anymore after the upgrade, and that you would loose the warranty, NOTHING ELSE.

    So I trusted them, like many people, I upgraded my 3GS baseband to 06.15.00 to get 4.2.1.

    Result after the upgrade :

    1) my GPS are screwed-up :-((
    2) my batteries drain twice faster than before :-((
    3) the push function doesn’t work correctly any longer :-((

    Questions :

    1) why didn’t they tell people about theses consequences before?
    2) Why didn’t they test a minimum before releasing an alpha version (not even a beta !) of jailbreak & desimlock?

    Just to mention, SAM doesn’t fix the GPS, neither the push function 🙁

  • charly

    I’m just p*ssed off by these amateurs from the dev-team :
    Downgrade 06.15.00 BB To Fix GPS Issue Coming After i4 Unlock

    Geohot wouldn’t have realeased an alpha version of redsn0w + ultrasn0w…

  • charly
  • i hope there is answer soon as i use navigation a lot

  • Hi
    just to let you no people i have un installed both tomtom and i go from my iphone and installed

    skobbler from apps store and it piked gps without any problem what i will do is re install tomtom and let you no if that worked

    please let me no if there is any other method many thanks

  • Gps

    @yunus, is your phone 3g o 3gs

  • Hi my phone is 3gs also like to report is Sygic uk and Ireland work quie well and that is what i been using igo and tomom dont work waiting for fix like all

  • Glenn

    It also seems that in the UK someone has got wise to this as after upgrading my baseband to 06.15 within 3 months my phone was barred. Bill Paid. also when looking to sell it on ebay i have come across another couple of people whos iphones are barred which who have also done the baseband upgrade 🙁

  • dr.dre

    hello guys , i unlocked my iphone 3g 4.2.1 after upgrading to 6.15 using pwnage tool and ultrasnow .. i was very well aware of gps problems which a lot of people have reported .. but my problem is my 3g.edge/gprs is not working .. it says internet connection is offline although the edge symbol E is displayed beside the carrier on the left upper corner .. i can connect to the net only with wifi 🙁 this is a big problem coz i dont have access to wifi everywhere i go .. im thinking mine s the only one with this problem coz everybody seems to having battery and gps problems ..
    can somebody help me ?
    also my TSS request is still pending .. is it related to that ?

  • mel

    hey dr. dre, is your edge working now? my and the wife was working fine this whole week until todau. out of nowhere, we both dont have the E display. is this a tmobile issue?

  • Dzej

    I have 3g with 6.15bb too. I can connect to internet only with wi-fi, with 3g/gprs no!

  • kausik

    hey i use a navigon app as my GPS but after updating to bb 6.15.00 and unlocking i lost the gps signal on my iphone 3gs running ios 4.2.1

  • Cl33nSw33p

    First of all, I think its really stupid to give the Dev Team a shitload of grief. Did you pay for the upgraded BB and Unlock? Was it to the Dev Team? Id love to see those that bitch work on the mobile substrate and bb hacks like these guys do. If you think you can do better, GO RIGHT AHEAD!!!! Upgrading my iphone 3g to 4.2.1 was a great choice for me, but I should have blocked the BB upgrade. I need GPS for daily travel. I am on the road ALOT, and not having GPS on my Iphone anymore has been a major bummer. Am I mad at the Dev team for it? Hell no. I cant hack into IPhone IOS and do anything short of mess it up! Am I eagerly awaiting a fix? Sure as shit! But talking smack about these guys for doing work for free and finding solutions to issues we all face with our phones should not come with abuse, ya know? Hey, it doesnt work. Well, if we wanted 100% reliable IPhones, we would all be with Verizon or AT&T now wouldnt we? Sometimes people can really be major Douche Bags.

  • jorim van der saar

    Unlocked ios 4.0.2 – BB 06.15.00 – GPS issues battery drain FIX? any comments>?

  • Skyler

    3G on ios 4.2.1 with 6.15 baseband. GPS doesn’t work very long, if I start out at a wifi hotspot and start moving away from it it will work for about 500 meters or so then it goes haywire after that. GPS was slow before the baseband unlock so I decided the risk was worth it since I needed the iphone as a phone. I’ve been using it as a itouch but someone needed my other phone so I decided to unlock. For the battery problems activating the phone with a official sim card seems to have solved the battery drain issue for me, I couldn’t quite figure out how to use SAMperfs in Cydia and I borrowed my sisters sim card.

  • i upgraded my iphone 3gs old bootrom baseband to 06.15.00 to unlock ios 4.1. never had problems with gps and instead wifi issues. it has a very short range with different types of routers. if there is a fix please help!