There are two ways to do the relearn on the Fit. With a tool like
or with a scantool that supports TPMS module bi directional controls.
With the tool you store each ID in the tool either manually or by querying each sensor. Plug it into the OBD2 port and it does the rest. With the scantool you need to know each sensor ID beforehand. Then you can manually enter them into the TPMS module.
The TPMS module will store codes. Assuming a bad sensor and not a wiring/module issue (very rare). You can also go into live data and check each ID for bad data. But, if you don't know where each sensor is in relation to the wheels it's not very useful. If you don't have a reader/programmer tool you'd have to break down each tire to find the bad sensor.