TheGad

Finally you are able to downgrade your 3Gs & 3G Baseband from 6.15.00 to 5.13.04 in order to fix the GPS not working. This will work on any 3Gs or 3G that is currently running the 6.15.00 Baseband. Get your downloads below and follow the video above for the tutorial!

Redsn0w has now been Updated to 0.9.14b2 to fix any issues users were having with downgrading!
You will need to download Redsn0w 0.9.14b2, Your 5.1.1 Official Firmware for 3Gs Only and iDetector is Optional.

Redsn0w 0.9.14b2 for Windows: Windows Redsn0w 0.9.14b2
Redsn0w 0.9.14b2 for Mac: Windows Redsn0w 0.9.14b2
iPhone 3Gs 5.1.1 Official IPSW Firmware: iPhone 3Gs 5.1.1
iDetector : NEW/OLD Bootrom Detector NOTE: To check your 3Gs Bootrom on a Mac, Click Here: Mac Bootrom Guide