The car engine should be fixed as early as possible and that is why, meaning of the car engine P1782 Code is important. The car engine should be checked to know the problem and know the real cause of the car engine problem. However, the general meaning of the code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 1 for MFG – Manufacturer Specific. 7 for Auxiliary Emission Controls. 8 for Exhaust Gas Recirculation System Valve 1 and 2 for A/C System High Pressure High Temperature. Engage an automobile engineer to know the cause and solve the problem.