The automobile dictionary meaning of the engine code is also important thing. You need to know the real meaning of the car engine code. The car engine P2816 Code is also meaningful and real meaning of the code is found from the automobile manufacturer of your car. Do not fix the car engine by immature person or engineer. The automobile dictionary meaning of the code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 2 for MFG – Manufacturer Specific. 8 for Ignition System Or Misfire. 1 for Low Coolant Circuit and 6 for Cruise Control System – Vehicle Accel Too High.