It's been answered... look at the model number in the back. If it ends with an A you've got the sensor. If not then you don't have it.
I see dead phones, calling around just like regular phones.
My cell phone history: Ericsson GH788, Mitsubishi T200, Sanyo BAM 201, LG V111, Ericsson T28, T39, T68, T68i, Panasonic GD87, GD55, Nokia 3660, 6600, Motorola V525, A360, Panasonic X701, Palm Treo 600, HTC Blue Angel, Wizard, Herald, Kaiser, Touch Pro 2, Doubleshot MT4GS