The automobile dictionary meaning of the engine P0521 Code is not fruitful for solving the car engine. You should fix the car engine according to the right meaning of the engine code. The automobile dictionary meaning of the engine code is P for Powertrain Code Problem is related engine, transmission and emissions systems. 0 for SAE – Generic. 5 for Computer And Auxiliary Outputs. 2 for Air Conditioning (A/C) Clutch Feedback Circuit High Voltage and 1 for TFP Valve Position Switch-Drive Without Drive Ratio. The right meaning of the code is found from your car manufacturer and if you know the process of solving the car engine, you can try to fix the car engine.