Bobcat S510 09-21 Error Code
09-21 Error Code
Fuel Level Out Of Range High is the main cause of 09-21 error.A significant number of consequences can be suffered due to an overheating engine with code 09-21. The problem might be a blown gasket or something related to the fuel tank.

Tip For S510 Model
The overload warning device (if equipped) senses
hydraulic pressure in the boom lift circuit. When the
hydraulic pressure in the boom lift circuit reaches a
predetermined pressure setting, a buzzer will sound that
indicates an overload condition.
If the buzzer sounds, immediately move the arm closer to
the excavator and lower the boom. Reduce the size of the
load before attempting to re-lift the load.