The engine P1912 Code has different meanings and those meanings are the automobile dictionary meaning and the real meaning of the car engine code. The main problem of the car engine can be found by the real meaning of the code. The powertrain problem of the car engine can be fixed easily and that is why, you should know the actual problem of the car engine. The automobile dictionary meaning of the engine is p for Powertrain Code Problem is related engine, transmission and emissions systems. 1 for MFG – Manufacturer Specific. 9 for Fuel And Air Metering. 1 for Low Coolant Circuit and 2 for A/C System High Pressure High Temperature.