Before you start the procedure you need:
1. Rooting - This rom is rooted.
2. Get Mobileuncle Tools from play store
3. Get GPS Test from play store
4. Get Root explorer from play store or internet.

Procedure should be done outdoors:
1. Turn GPS off on your phone.
2. Open Root Explorer and find the mtkgps.dat file in /data or /data/misc
3. Delete mtkgps.dat
4. Reboot phone
5. Open Mobileuncle Tools
6. Tap on 'Engineer Mode'
7. Tap on 'Engineer Mode (MTK)'
8. Scroll across to 'Location'
9. Tap on 'Location Based Service'
10. Tap on 'AGPS' and then make sure 'A-GPS On/Off' is checked
11. Tap on 'EPO' and then make sure 'Enable EPO' is checked
12. Swipe down (notification bar) and turn GPS on
13. Hit back and then tap 'YGPS'
14. Wait until you get position lock (mine took about 5 seconds).
15. This process should create a new mtkgps.dat file.
16. Hit home button and open GPS Test.
17. You should get a position lock reasonably quickly.


ที่มา:  http://www.thlmobilestore.com/news/gps-fix/