The car engine may get problem for different causes and it is necessary to know the real cause of the car engine problem. The car engine P1783 Code is found from the car engine by the test. The automobile dictionary meaning of the code lets you know about the problem in general. 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 3 for Transmission Control Module Reprogrammable Memory. Get help from an automobile engineer.