The automobile dictionary meaning of the engine code also known as general meaning of the car engine code. The car engine P1918 Code is found for the test and meaning of the car engine code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 1 for MFG – Manufacturer Specific. 9 for Fuel And Air Metering (Injector Circuit Malfunctions Only). 1 for Low Coolant Circuit and 8 for PCM Stack Overrun. The engine P1918 code is a kind of powertrain problem and it should be fixed fast. Although, the problem is minor but it may be serious later.