tilt module does not work after dropping the phone

First thing that I would is do do a reset and see what happens.

1. Hold down the home button (on the front of the phone) and the hold button (on the top right corner of the phone) at the same time.

2. Don't let them go

3. If the slider to turn the phone off appears, continue holding both buttons.

4. After 10 seconds or so, the phone's should go dark.

5. Then hold down the hold button at the top right until the Apple logo appears onscreen and the phone begins to boot up.

If that does not work I would try a restore with iTunes. Just make sure you have all your stuff backed up.The instructions for that are on the Apple Support Site

If any of this is still unsuccessful I would disassemble the iphone and take a look at all connections. Make sure that hey are all seated properly and that all cables are in good working order and without any visible damage. Take a look at the pictures on Phonewreck it does show you the location of the accelerometer check for any damage on that as well. Good Luck with this and let us know how it is going.