That’s on an LG running 4.4.2, but I don’t have another device nearby to check to see if that is universal with Android or a carrier/OEM added setting.You've just read or heard that your phone is due for an update—maybe just bug fixes, or possibly a big version upgrade. Dial this keypad combination to force a "checkin" and possible upgrade.If there's no update available for your phone from your carrier, then this trick won't magically compile and distribute one, of course.
Sometimes it works, and sometimes it doesn't—but it doesn't hurt.
To get your phone into the queue right away, dial , substituting the dial pad numbers for the letters.
I used it on a Nexus S to pick up a bug-fixing upgrade, and users of other Android phones on different networks, like the Droid Eris on Verizon, have seen some success with it.
How To: Update your preferred roaming list (PRL) on your CDMA device PRL is a list that allows your phone to roam off of towers that are not part of your native network, such as a sprint phone connecting to a former Alltel tower if none of its own are available.
Because roaming agreements are constantly changing and new towers are added all the time, it's important to keep this list up to date.
For most CDMA carriers (including Verizon), you can update your PRL by dialing *228 and selecting the appropriate option.
For example, on a Verizon phone you dial *228 and then select option 2 and listen to the horrible programming music while your phone downloads the latest PRL."The PRL is the Preferred Roaming List for CDMA phones like Sprint or Verizon.
It basically tells your device the information it needs to contact to cell towers in your location and improve your coverage.
Since the towers’ frequencies aren’t all the same, you will need a new PRL for the different frequencies.
Usually the phone will update the PRL for you, but if you are travelling a lot you might want to update it manually from time to time in an attempt to get better coverage.
Under Settings System Updates there is an an option to update the PRL manually on my phone.