Bobcat 773 12-21 Error Code
12-21 Error Code
Auxiliary Pwm Switch Out Of Range High is the main cause of 12-21 error.The condenser converts gases into liquids, which expels heat from your rig. Materials can build up over time, causing a layer of dirt and grime to form on the condenser's coils. Your AC system will only blow hot air since the refrigerant fails to cool down.
Tip For 773 Model
It is recommended in cold weather to cycle the glow plugs twice before attempting to start the engine. This will allow for additional heating time for cold weather starting.