[HapaHaole]

Here is what Toyota says for this code.

P0462
Fuel sender gauge assembly voltage is less than 0.4 V for 2.5 seconds or more.
(2 trip detection logic)

P0462, P0463
If an open or short in the fuel sender gauge signal line is detected, the ECM interprets this as a malfunction in the fuel sender gauge, and stores the DTC.

P0462
Fuel sender gauge voltage (Fuel level)
Less than 0.4 V (100.7%)

Connect the Techstream to the DLC3.
Turn the ignition switch to ON and turn the Techstream on.
Clear DTCs (even if no DTCs are stored, perform the clear DTC operation) 2014 MY FR-S [07/2013 - ]; FA20 ENGINE CONTROL: SFI SYSTEM: DTC CHECK / CLEAR .
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the Techstream on.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher .
With the vehicle stationary, depress the accelerator pedal and maintain an engine speed of between 2500 and 3000 rpm for 40 seconds or more [A].
Drive the vehicle at 10 km/h (6.25 mph) or more for 1 minute or more [B].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.

Enter the following menus: Powertrain / Engine / Trouble Codes.
Read pending DTCs.
HINT:
If a pending DTC is output, the system is malfunctioning.
If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P462 or P0463.
Check the DTC judgment result.
TECHSTREAM DISPLAY
DESCRIPTION
NORMAL
DTC judgment completed
System normal
ABNORMAL
DTC judgment completed
System abnormal
INCOMPLETE
DTC judgment not completed
Perform driving pattern after confirming DTC enabling conditions
N/A
Unable to perform DTC judgment
Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
HINT:
If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the test result is INCOMPLETE or N/A and no DTC is output, perform a universal trip and check for permanent DTCs 2014 MY FR-S [07/2013 - ]; FA20 ENGINE CONTROL: SFI SYSTEM: DTC CHECK / CLEAR .
HINT:
If a permanent DTC is output, the system is malfunctioning.
If no permanent DTC is output, the system is normal.