Theres one or 2 sensors in the front but I think they're on the frame down low. Google it!
Edit: looks like they're on the radiator support. Ahhh that's what those things were- I just had my radiator support out and r&r'd two sensors but didn't realize they were impact sensors.
"There are 2 impact sensors up front on the bottom of the radiator support. the diagnostic module is also a sensor. (I would think it would be the least likely to go out) To unplug the ones on the radiator support pull the orange retainer clip out and then unplug the yellow connector (After the battery is disconnected) If memory serves me well they are held on with inverted torx bolts. (Loosen then a little and slide the sensor to remove)"