The automobile dictionary meaning of the car engine P3484 Code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 3 for SAE – Generic. 4 for Transmission. 8 for Exhaust Gas Recirculation System Valve 1 and 4 for Cruise Vehicle Speed/Set Speed Difference Too High. If you know the real meaning of the code, then that will be perfect and use that meaning of the code for solving the car engine. You must try to fix the car engine by an expert automobile engineer. If you have all necessary tools and you know how to fix the car engine, then you can fix the car engine in you place.