Hi,
Thanks for using justanswer.

Try out these steps and see if it helps,

1. Firstly you can try removing the batteries and replacing it with a new set of fully charge ones.

2. If the batteries ran down while you were taking photos with the lens extended, you might also get this error. Remove the the memory card and replace the batteries with a fresh recharged set. Try to power on the unit with the fresh set of batteries while the memory card is removed.

3. Connect your camera to your computer using your USB DATA cable which came with the camera. Once the camera gets power in this mode, the screen should stay off, hence, supplying the lens with more power to push or pull out/in.

4. Place the camera on a study table with the lens pointing to the ceiling. With a fresh set of batteries installed(Do this without a memory card) hold down the shutter button while you power on the unit.

5. Now, you can either use a compressed air canister to blow around the lens area. This will result in the sand or dust particles to be blown out of the area between the lens and the barrel. Or, you can use a vacuum and and carefully place the nozzle around the lens to remove out the particles.

6. Tap your camera with the palm of your hand a couple of times to displace the lens into the original position, or to dislodge particles in the lens barrel.Try gently pushing/pulling/wiggling the lens while powering up the unit.
Hope it helps, if not then contact the manufacture http://www.canon.com/.
First quote for the cost of repair.
It would be kind enough if you please remember to click the green ACCEPT button.


Regards.