The meaning P20DD Code is an important thing and if you do not get the meaning of the code, you cannot solve the car engine problem. The general meaning of the code is available online and you do not need to use this meaning for solving the car engine problem. The P for Powertrain Code – Problem is related engine, transmission and emissions systems. 2 for MFG – Manufacturer Specific. 0 for Transmission. D for BBV Sensor Circuit Low Voltage and D for TFP Valve Position Switch-Drive Without Drive Ratio. You can understand that where the main problem is of the engine.