Location data comes from 3 possible sources:
- actual GPS chip (not all iOS devices have one)
- known position data of the WiFi node you may be connected to
- known position data of the cell tower(s) you are connected to.
So the question now becomes "do any of those location data sources use cellular data"?
- Unlikely since the data comes from the GPS chip and satellite data.
- Possibly since if WiFi is enabled on the device, but you are not connected via WiFi, cellular data may be used to obtain the estimated position of those WiFi nodes (if not known already by your iOS device).
- Maybe. Does the cell signal include the position data of the tower? If so, no data from a data plan should be used for this data. If not, then a small amount of the data plan may be used to obtain the data.