The meaning of the engine P0811 Code is available from different sources and you need to find the real meaning and you use automobile dictionary meaning of the code when you do not find the real meaning. The automobile dictionary meaning of the code provides general information what may not seriously harmful for solving the car engine problem. The automobile dictionary meaning of the code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 0 for SAE – Generic. 8 for Ignition System Or Misfire. 1 for Low Coolant Circuit and 1 for TFP Valve Position Switch-Drive Without Drive Ratio.