The engine P0858 Code supports the automobile engineer to solve the car engine and real meaning of the code helps most for solving the car engine. You can use general meaning of the code what is found from the automobile dictionary meaning and it is p for Powertrain Code Problem is related engine, transmission and emissions systems. 0 for SAE – Generic. 8 for Ignition System Or Misfire. 5 for TP Sensor Learn Not Complete and 8 for PCM Stack Overrun. However, you should be careful about the car engine’s problem and you must not drive the car if the car engine is not fixed properly.